List of Dexter characters
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This is a list of characters from the Showtime TV series Dexter and the Jeff Lindsay novels, including Darkly Dreaming Dexter (on which the show was based), Dearly Devoted Dexter, Dexter in the Dark, Dexter by Design, and Dexter is Delicious.
Main characters 
Dexter Morgan 
- Michael C. Hall
- Maxwell Huckabee (Dexter at 3)
- Dominic Janes (preteen Dexter)
- Devon Graye (teenage Dexter)
Dexter "Dex" Morgan (born Moser) is the main character and narrator of the series. Dexter is a forensics expert and blood spatter analyst employed by the Miami Metro Police Department, but has a double life as a serial killer. As young boys, he and his older brother Brian witnessed the murder of their mother, Laura Moser, and were left for two days in a shipping container filled with blood. The incident left them psychologically scarred. Soon afterwards, Dexter was adopted by Harry Morgan, who hoped to help repress his memory of the death of his mother. However, he soon realized that Dexter had an insatiable urge to kill that would begin to intensify. Harry, frustrated with the number of people who avoided justice, decided to train Dexter as a killer who would target and dispatch other murderers.
Dexter considers himself emotionally divorced from the rest of humanity; in his narration, he often refers to "humans" as if he is not one of them. Dexter makes frequent references to an internal feeling of emptiness, leading to several attempts in his youth to "feel alive". Dexter claims to have no feelings or conscience and that all of his emotional responses are part of a well-rehearsed act to conceal his true nature. In the first season of the television series he had no interest in romance or sex; this changed when he became involved with Lila in the second season. He initially considered his relationship with Rita to be part of his disguise. However, by the end of the fourth season, Dexter had fully evolved into a family man and wished to rid himself of his self-titled "Dark Passenger".
There are chinks in Dexter's emotional armour, however. He acknowledges loyalty to family, particularly his now-deceased, adoptive father, stating "If I were capable of love, how I would have loved Harry." Since Harry's death, Dexter's only family has been his sister, Debra Morgan, Harry's biological daughter. At the end of the first novel, Dexter admits that he could not hurt Debra or allow Brian to harm her because he is "fond of her".
Dexter likes children. The flip side of this affection is that Dexter is particularly wrathful when his victims prey on children. In the book Dearly Devoted Dexter, Dexter realized that Rita's son Cody was showing the same signs of sociopathy as Dexter had at that age, and looked forward to providing him with "guidance" similar to that which Harry provided him. Cody's perceived sociopathy has not been shown in the television series.
This also gives him a reason to continue his relationship with Rita, to whom (as of Dearly Devoted Dexter) he is engaged because of a misunderstanding. At the beginning of the third book, Dexter in the Dark, it is revealed that Cody is not the only one with dark impulses, as Astor too pressures Dexter to teach her. Dexter comes to accept his role as a stepfather to both children very seriously in Dexter in the Dark. For example, while on a stakeout, he begins to wonder if Cody has brushed his teeth before going to bed and if Astor had set out her Easter dress for photo-day at her school. These thoughts distract him while he is waiting for an intended victim, which thoroughly annoys him. In the TV series, Dexter also takes a detour in his code of only killing murderers in order to dispose of a pedophile who is stalking Astor.
Animals do not like Dexter, which can cause noise problems when Dexter stalks a victim with pets. He is quoted as having once had a dog that barked and growled at Dexter until he was forced to get rid of it, and a turtle, which hid in its shell until it died of starvation rather than have to deal with Dexter.
Rita Bennett 
Rita Bennett was Dexter's girlfriend and later wife. Rita is portrayed as a mother, who is slowly recovering from being physically abused by her ex-husband, Paul, and having difficulties maintaining a sexual relationship. Rita tentatively starts a relationship with Dexter, while remaining unaware of his extra-curricular activities. In season two, Rita's relationship with Dexter becomes troubled. After discovering that Dexter framed her ex-husband Paul with drug abuse, she suspects that Dexter owned the drugs himself. She pushes him into Narcotics Anonymous, but begins to suspect that he is having an affair with his sponsor, Lila, and breaks up with him. In anguish, Dexter turns to Lila, and consummates what had before been a platonic relationship. After Dexter lies to Lila about working late (he had gone to kill Jimenez), Lila breaks into Rita's house, afraid that they had rekindled their relationship. Angered, Dexter breaks up with her. His breakup with Lila, his love for Rita and her children, and his sincere regret over what he had done convinces Rita to start dating him again.
In season 3, Rita suddenly discovers that she is pregnant with Dexter's baby. Believing that being a parent is one of her main achievements, Rita decides to keep the baby, and leaves Dexter's role in the child's life entirely up to him. After much deliberation, Dexter decides (with Debra's help) that he will be there for the child and Rita accepts his marriage proposal. Rita loses her job when she is rude to a customer, but gets back on her feet by working as an assistant to Sylvia Prado.
After the baby, Harrison, is born, Rita and Dexter move into a house together in the suburbs. Rita begins to notice a pattern of lies from Dexter, including deceiving her about the concussion he suffered in the car accident and the ownership of his old apartment. Rita and Dexter then go to a marriage counselor, who allows them to sort out their problems and instigates peace between them. However, their neighbor, Elliot, begins to fall for Rita, kissing her and pointing out that Dexter is never home. Though she initially kisses him back, she quickly ends it before something begins. In the Season 4 finale, Rita is murdered by the Trinity Killer, leaving her son Harrison sitting in a pool of her blood.
Debra Morgan 
Debra Morgan (known as Deborah Morgan in the book) is the younger foster sister of Dexter and biological child of Harry Morgan. Debra believed that she truly knew her father, but is unaware of the secrets he kept, especially concerning Dexter (whom she sees as a true brother). Inspired by their father's legendary police career, Debra joined the police and desperately yearned to become a homicide detective. Initially assigned to Vice, she was transferred to Homicide at the start of the first season. Being new to the job and very insecure, she largely relied on Dexter's expertise on murderers to solve difficult cases. Debra met Rudy Cooper, who unknown to her is the Ice Truck Killer using her to get close to Dexter. She falls in love with him, but is later kidnapped by him in order to be able to reveal himself to Dexter. She is bound to a table in the same manner that Dexter kills his victims, while Dexter and Brian discuss her fate. In the show, she is unconscious, but in Darkly Dreaming Dexter, she is awake and finds out that her brother is a killer. Debra is severely affected by Rudy's betrayal; she moves in with Dexter for fear of being alone.
Throughout the second season, Debra stays in her brother's apartment as she deals with the trauma of what happened, but leaves his apartment in a mess. Debra is a key member of the police task force in charge of finding the Bay Harbor Butcher, who is secretly Dexter. She falls for an older man, Frank Lundy, the FBI agent in charge of the case, all the while improving her ability on the job. By the end of Season 2, Debra has recovered from the trauma of the Ice Truck Killer, confident as an officer, and is determined to get her detective shield.
In Season 3, Debra has had her hair cut to shoulder length, has "sworn off men, liquor and smokes" and is even more determined to get her silver detective shield. She is working with a new partner, Detective Quinn, but has been approached by an Internal Affairs officer who tells her that her partner is being investigated as a dirty cop, but she refuses to help them. She was originally part of the team investigating the murder of Miguel Prado's brother, Oscar, but because of her lack of tact and people skills she was removed from the case by newly-promoted Angel Batista; however, the case she had been assigned (the murder of a young woman) was eventually found to have been connected to the Skinner case, which she solved with the help of Anton, a C.I. whom she started dating after saving his life from the Skinner. Because of her success on the Skinner case, she was promoted to detective at the end of the season.
She is known to have a very foul mouth, and she hardly speaks a sentence without swearing. This has nearly gotten her into trouble, as she often speaks profanely to her superiors, only to realize a few seconds after. It finally got her into trouble in the third season, as a poorly-timed public comment caused her to be kicked off the Freebo case. She is also known for being easily angered and frustrated by suspects. Though she is frustrated at Dexter's inability to open up to her, she has defended him on more than one occasion.
A conversation between her and Dexter leads to her finding out that her father slept with one of his confidential informants. She investigates the files on Harry's informants and interviews some of them, hoping to find the one with whom Harry had an affair. One of the files is shown to be that of Laura Moser. Also during this time, her relationship with Anton had been breaking, especially now that he had secured a gig in the city instead of on a cruise ship. Also, Frank Lundy returns to Miami to hunt the Trinity Killer, and Debra once again becomes involved with Lundy. Soon, both she and Lundy are shot by an unknown assailant suspected to be the Vacation Killers. In her hospital bed, she confesses to Anton that she slept with Lundy, prompting him to leave her. Lundy dies, and she eventually concludes that the Trinity Killer must have been the shooter. As a result, Debra opens an investigation on the Trinity Killer. However, it is later determined that Trinity could not have been the shooter, since her wounds from the bullet were at a horizontal line, therefore someone of Masuka's height had to be the shooter. During a Thanksgiving dinner Debra remembers a conversation she had with Christine Hill and realizes Hill has knowledge of the shooting that no one outside the police department should possess. This leads Debra to believe that she was the shooter. This is backed up later when it is revealed that Hill is the daughter of Trinity. Hill later confesses to Debra that she was the shooter, and proceeds to shoot herself in the head. Due to her solving the Lundy killing, Debra restarts her search for Harry's C.I. mistress, and finds out about Laura Moser, and the fact that Dexter and the Ice Truck Killer were brothers.
James Doakes 
James Doakes is a sergeant serving as lead case investigator to Miami Metro PD's Homicide. Doakes had killer impulses which drove him to divorce his wife, confessing that if he had stayed with her any longer, he would have killed her.
Doakes instinctively hates Dexter; and is the only person in Dexter's life who can see through his mask of normalcy, Doakes suspects that Dexter is hiding something and has no reservations about telling him so. Ultimately, Doakes realizes that Dexter is withholding vital information on the Ice Truck Killer case and his frustration drives Doakes to physically attack him, only for Dexter to expertly fight back. Doakes' friend LaGuerta tells him to back off, but Doakes begins following Dexter in secret.
Doakes temporarily ends his stalking when he finds Dexter attending a Narcotics Anonymous meeting, supposedly for heroin addiction. Doakes erroneously believes Dexter's dark secret is that he is a drug addict whose addiction is caused by work-related stress, Doakes tells Dexter that he has seen many policemen led down the same path. Feeling sympathetic towards Dexter, Doakes briefly leaves him alone.
Doakes resumes the hunt, however, when Debra innocently reveals that Dexter does not so much as smoke. On finding Doakes meddling in his past again, Dexter goads him into a seemingly unprovoked fight in front of the entire squad room. Doakes breaks into Dexter's apartment, and stumbles upon Dexter's blood slide collection box, and realizes Dexter's secret—that he is the Bay Harbor Butcher. Ironically, Doakes is by now the prime suspect in the case, thanks to Dexter's manipulation of the evidence.
Doakes attempts to apprehend Dexter himself in the Everglades, but Dexter gets the upper hand and locks him in Jimenez's cabin while deciding what to do. Doakes tries to convince Dexter to turn himself in; however, Lila Tournay finds the cabin and blows it up by igniting propane tanks after finding out that Dexter is the Bay Harbor Butcher. Doakes' incinerated remains are found along with the dismembered body of Jose Garza, and so the case is closed, with the official conclusion being that Doakes was the culprit.
María LaGuerta 
Lieutenant María LaGuerta is a tough, determined woman in command of the Homicide division. At the series' beginning, she had a sincere dislike for Debra which in later series has all but disappeared. In the first season, she made no secret of her attraction to Dexter, with whom she flirted constantly, to his discomfort. After the first season, however, it is suggested that she sees him more as a good friend. At the end of the first season, she is removed from command.
She returns to her old job once the new Lieutenant, Esme Pascal, proves to be unstable (a state LaGuerta intentionally worsens by having an affair with Pascal's fiancé). When her friend and former partner and lover, James Doakes, becomes the prime suspect in the Bay Harbor Butcher case, she tries to clear his name. However, Doakes is found dead in a seemingly accidental explosion along with the body of drug dealer Jose Garza, and the case is closed. As she recovers from the trauma of Doakes' death, she leads an investigation into the murder of Oscar Prado, the brother of her ex-boyfriend, Miguel Prado. She also develops a close relationship with defense attorney Ellen Wolf, and is devastated when Wolf is found murdered. After Miguel's own murder (ostensibly at the hands of The Skinner, but in reality by Dexter). She wants to find admissible evidence to prove he killed Wolf, but Dexter is able to convince her that doing so would only hurt Miguel's family and the Cuban community, and that even then there is a high chance that nothing will be proved. Reluctantly, LaGuerta drops it.
At the start of Season 4, she is shown to be romantically involved with Angel. They keep their relationship hidden from the rest of the homicide department, aside from Dexter, who both Angel and LaGuerta confide in. Their relationship hits a roadblock when she tells their superiors about their relationship so that it cannot be used against them during a trial. The consequence of her disclosure is a threat of reassignment; either Angel or LaGuerta will have to move out of Homicide. Deciding that their jobs are integral parts of who they both are, the two decide to end their relationship, and sign affidavits to that effect. Staying away from each other does not prove easy however, and they begin having secret liaisons once more. In order to circumvent a reprimand from higher up, and also as a result of their deepening feelings for one another, they secretly get married with Dexter as witness.
LaGuerta and Batista divorce in between seasons 5 and 6.
In season 6, Captain Matthews is promoted to deputy chief and LaGuerta is promoted to fill Matthews' position. It was later disclosed that LaGuerta had blackmailed Matthews in order to become the captain. LaGueta wanted to install Angel Batista, whom she can trust, to be the new lieutenant of homicide division, but as a payback to LaGuerta, Matthews appoints Debra Morgan to be the new lieutenant instead. Later in Season 6, when Matthews was involved in a prostitute's overdose death, LaGuerta used Debra Morgan to keep the case alive and eventually leaked the information to the police chief, who forced Matthews to retire. It was implied LaGuerta would become the next deputy chief.
At the onset of Season 7, LaGuerta finds the blood slide of Travis Marshall at the scene of his death. Remembering that this is the MO of the Bay Harbor Butcher, she then launches an independent investigation as to whether the Butcher was still active and James Doakes was innocent. In Season 7's finale, LaGuerta finds out Dexter is the Bay harbor Butcher, and arrests him. Dexter, anticipating LaGuerta's move, made it look as though she was framing him as the Butcher. LaGuerta then finds more evidence of Dexter and Debra's involvement in the death of Travis. She eventually gets killed by Debra, with a shot to the chest, who finds her and Dexter in a shipping container as Dexter was trying to frame her for the murder of the killer of Dexter's mother, Hector Estrada.
Angel Batista 
Angel Batista is a detective in Miami Metro Police Department's Homicide Division. Batista is basically good-natured, with a dry sense of humor. He is also totally honest, at the request of his father on his deathbed. Angel is also shown wearing a trilby hat almost all the time. After having an affair with another woman, he confesses his actions to his wife; she immediately ends their relationship, although it takes months for the painful separation to conclude.
Angel takes an interest in Lila and eventually ends up sleeping with her. However, Lila takes rohipnol and then files rape charges against Angel. During this period, Dexter admits that if he were "normal", he would want to be a man like Batista. Ultimately, the charges are dropped once Lila moves to Paris.
At the start of season 3, Batista is promoted to sergeant and made the department's new lead case investigator to replace the now-deceased Doakes. However, he risks his career by attempting to sleep with a hooker who turns out to be an undercover cop. After persistent but gentlemanly advances, Angel begins a relationship with the other officer, Barbara Gianna.
By the start of Season 4, it appears that Angel and Barbara have amicably split, and he has a romantic involvement with LaGuerta, although this is kept hidden from those they work with. In "Hello, Dexter Morgan", they secretly get married with Dexter as witness. By season 5 their marriage has become common knowledge throughout the office.
Batista and LaGuerta divorce in between seasons 5 and 6.
In season 7, Batista buys a restaurant, and announces his retirement.
Harry Morgan 
Harry Morgan is Dexter's adoptive father. When alive, he was a detective and highly-respected member of the Miami Police Department. In the course of a high-stakes drug case, Harry began an illicit relationship with Laura Moser, Dexter's biological mother, to gather information and evidence on the drug lords in question. Laura was discovered and made an example of; she and three others were executed with chainsaws in a shipping container. Her sons, Brian and Dexter, were left in the container for several days until Harry and a police team recovered them. Harry adopted Dexter, while Brian was sent into foster care.
At first, Harry attempted to manage Dexter's violent urges by only allowing him to kill animals, but he eventually came to the conclusion that Dexter's pathology could not be repressed, only controlled: Harry decided to train the boy as a vigilante, to hunt and kill murderers without leaving any clues. Dexter prized these lessons as a means to fulfill his desires with his father's approval, dubbing them the "Code of Harry". Harry's relationship with his biological daughter Debra, meanwhile, was more complicated. She craved her father's approval, but felt that he favored Dexter.
When Dexter was 19, Harry fell seriously ill and gave Dexter "permission" to kill one of his nurses, who was intentionally poisoning him with morphine. A year later, when Juan Rinez, a pimp who was murdering prostitutes, was released due to a faulty search warrant, Harry lost his temper and told Dexter he was right in training him. When Dexter killed Rinez, Harry was horrified by the way Dexter proudly showed him the pimp's dismembered body. Harry committed suicide a few days later, by overdosing on his medication.
Vince Masuka 
Vincent Masuka is the Miami Metro Police lead forensics investigator and works alongside Dexter in the lab and in crime scenes. He often cracks innuendo to the rest of the team, and harbors decidedly unrequited feelings for Debra. He is portrayed as obsessed with sex, often makes inappropriate comments with implied sexual meaning on the crime scenes ended with characteristic for him laugh. The kinkier the better- he is not shy about propositioning any woman he meets. However, he has been able to tone it down when the situation calls for it, like when Angel was in hospital, as well as calming Debra down when Lundy returned. Detective Joey Quinn even confronted him about it, stating that his comments are why nobody likes to be around him, only for Vince to harshly brush him off. However, he seems to accept Joey's explanation when no one came to see his speech on his newly published work, for which he cleaned up his act and dressed formally, but soon returned to his former self. In the books, Dexter feels a kinship with him as, like him, he hides who he really is. In the novel as well as in the series, he sets up Dexter's Bachelor Party and kidnaps him to get him there (where, in the belief that he had been kidnapped by Ramon Prado, Dexter slugged Vince in the eye just as he opened the car trunk). However, he falls for the female Party Planner and it has been suggested they are still in a relationship. He is also shown to be greatly distraught after seeing Rita kiss another man, leading him to try to tell Dexter. In season 5 it is discovered that he has a giant tattoo of a dragon on his back.
In the novels, he is the closest thing Dexter has to a friend; Dexter senses that they are both pretending to be normal, albeit for completely different reasons. In Dearly Devoted Dexter Vince throws a large bachelor party for Dexter within a few hours of finding out about his engagement, and in Dexter in the Dark takes his role as best man so seriously that he calls in favors to hire Manny Borque, a famous caterer, for Dexter's wedding.
Joey Quinn 
Joseph Quinn is a detective who transferred to the Homicide division after being in Narcotics before Season 3. Quinn takes a liking to Debra Morgan, even giving her a C.I. to help with the Oscar Prado case. Quinn's past is unknown and even called into question, as Debra is pressured by Internal Affairs agent Yuki Amado to gather evidence against him. Quinn got the Internal Affairs case dropped, and later confessed to Debra that the real source of the Internal Affairs investigation was from the death of a former partner of his and Yuki's who had a crystal meth addiction. Quinn knew about the partner's addiction but tried to offer private help instead of informing his superiors. He is seen at Dexter's wedding, despite Debra's advice to Dexter against inviting him.
At the beginning of season 4, Quinn is infuriated when Dexter botches a case he worked on. Soon afterwards, Dexter sees Quinn stealing money from a crime scene, and Quinn attempts to buy Dexter's friendship with expensive football tickets, but Dexter gives them away to Masuka. Meanwhile, Quinn starts a relationship with Christine Hill, a seductive reporter who takes advantage of his access to police information. After a confidential police lead appears in one of Hill's articles, Lt. LaGuerta warns Quinn to be wary of any reporter who squeezes him for confidential information over pillow talk. Nonetheless, Quinn tells Hill about numerous police reports (supposedly "off the record"), and she uses this information to expose Frank Lundy's return to Miami. Quinn breaks up with Hill after the article about Lundy, but they soon make up. Though more careful about what he says around her, Quinn still defends Christine when Dexter tells her to leave Debra alone, as Hill claims to have wanted to do a "hero piece" on Debra. All of this leads to Quinn developing a confrontational relationship with Dexter. After Hill, revealed to be Trinity's daughter, shoots herself, he is clearly distraught.
In Season 5, he strongly suspects Rita was really murdered by Dexter and not Trinity, because of subtle differences in MO and because Rita shared a kiss with the neighbor. He also believes that Dexter was the Kyle Butler that was hanging out with Arthur. He tracks down Trinity's son, hoping he can identify Dexter as Kyle, but he is stopped by the FBI and suspended by LaGuerta. Unable to continue, Quinn hires Stan Liddy to investigate Dexter. After a one-night stand with Debra, Quinn repeatedly tries to get her back into bed, eventually succeeding as the two begin to date, until Debra discovers that Quinn was suspended by LaGuerta for investigating Dexter, and not taking vacation days as he had said. Liddy begins to harass Quinn but Quinn does not wish to continue investigating Dexter because of his romantic feelings for his sister, Debra. Stan Liddy was killed by Dexter in self-defense. Quinn is the main suspect because there is blood on his shoe and numerous calls between his phone and Liddy. Dexter makes the blood evidence on Quinn's shoe go away and Quinn is once again a free man. Quinn thanks Dexter, who plays dumb and just says "For what? Just doing my job."
In Season 7, Quinn falls for Nadia, a stripper who works at a club, The Fox Hole, operated by the Ukrainian Koshko mafia. He steals evidence that would have convicted Isaak Sirko in an attempt to win Nadia's freedom from Koshko control. However, after freeing her from her strip club job, Nadia runs away to Las Vegas leaving Quinn brokenhearted. In the season finale he is seen having drinks with Angel Batista's sister.
Supporting characters 
Relatives of Dexter and Rita 
Astor Bennett 
Astor Bennett is the daughter of Paul and Rita Bennett. When Paul returns home from prison, Astor, who remembers her father's abuse (and is in fact the one who called the police on Paul), is saddened but comes to love her father, who appears to have changed; she did, however, force Paul to promise that he would not hit Rita again. She has a good relationship with both Paul and Dexter, oblivious to the tension between the two men. At the end of the first season, Paul is back in prison and Rita tells him that he can either explain to Astor and Cody all the bad things he had done or never see them again.
During season two, Astor tries to maintain her relationship with Dexter even though he broke up with her mother. Dexter's love for Astor and Cody helps convince Rita to rekindle their relationship.
In Season 3, Astor brings out a protective streak in Dexter, in that Dexter kills a pedophile who was targeting her. He also considers her and Cody his family; in the aforementioned episode, he refers to them as his "cubs", and later says that nobody hurts "his children". Astor is the maid of honor at Dexter and Rita's wedding.
In season 4, Astor starts acting out: being rude to both Dexter and her mother, being in a constantly angry mood, and flirting with older boys. She and Dexter come to a peace after he promises to stop treating her like a child and admits that sometimes he is simply "dumb". Her attitude improves following this, though not by much. When he tries to become more involved with Astor's life, she often became hostile, at one point even asking "why do you hate me?" when he tried to suggest some after school activity.
In Season 5, Astor lashes out at Dexter in anger, blaming him for the death of their mother and for raising false hope that they could be a normal family. In episode 2 she and her brother move in with her grandparents in Orlando after her mother's death. In episode 9 of the season, Astor appears at Dexter and Rita's old home, to Dexter and Lumen's surprise, since Lumen was residing in the home at the time. She and her friend were drunk and Dexter allowes her to stay there, wanting to patch things up with his stepdaughter. While initially uncooperative, when her friend's domestic abuse issues are brought to light, Dexter takes matters into his own hands and teaches Astor's friend's mother's boyfriend a lesson and drives him away. Astor thanks him for his support, having thought that he would not want to help, and invites him into their grandparents' house. By the end of season 5, Astor is ready to agree to spending the summer with Dexter.
In the books, Astor and her brother Cody are two parts of a whole, with Cody performing killings and Astor acting as a sort of mentor who watches. Both she and her brother are kidnapped in Double Dexter, by Jeff Lindsay.
Cody Bennett 
Cody Bennett is the son of Paul and Rita Bennett. Cody does not remember the abuse his mother suffered at the hands of his father, so, when Paul returns home from prison, he is overjoyed. He has a good relationship with both Paul and Dexter, oblivious to the tension between the two men.
During Season 2, Cody tries to maintain his relationship with Dexter, even though he broke up with their mother; he hides toys in his bag, forcing him to come to their home to return it, and asks Dexter to attend an oral report he makes in class. Dexter's love for Cody and Astor helps convince Rita to rekindle their relationship.
As Season 3 begins, Dexter's relationship with Cody has developed to such an extent that Cody asks him to be a speaker at his school for Parent's Day, while Dexter's presentation of himself as a blood-spatter specialist does not go well with the other kids, Cody tells him that it would have been worse if Dexter had not been there. He also considers Astor and Cody his family; he refers to them as his "cubs", and later says that nobody hurts "his children". Cody is the ring-bearer at Dexter and Rita's wedding.
Cody learns of his mother's death but does not show any hostility towards Dexter, even growing closer to him. But when Astor insists that she wants to leave Miami and live in Orlando with her grandparents, Dexter makes Cody go with his sister because he believes the bond between him and Astor is something he should preserve. In later episodes Dexter notes that he is still talking with Cody. After Dexter dropped Astor off, he claims that Cody has gotten a foot taller since he last saw him.
Cody returned in season 7, episode 8, along with his sister Astor.
In the books, Astor and her brother Cody are two parts of a whole, with Cody performing killings and Astor acting as a sort of mentor who watches. Cody is able to sense Dexter's "Dark Passenger".
Harrison Morgan 
- Brandon Michael Bass (dream version, in Finding Freebo)
- Harrison, portrayed by various uncredited babies.
- Luke and Evan Kruntchev (2010-2012)
Harrison Morgan is the son of Dexter and Rita Morgan and the half-brother of Cody and Astor. Harrison first appears in season 4, crying in the car while Dexter tries to calm him down. His crying keeps Dexter constantly fatigued in the first part of Season 4 which in turn causes Dexter to make mistakes while practicing his "hobby". Dexter appears to care for him genuinely. At the end of Season 4, he is found by Dexter, crying in a pool of his mother's blood, much as Dexter had been found by Harry when he was three.
In season 5, Harrison is raised by Dexter, and is watched during the day, and sometimes night, by his Irish nanny, Sonya. It is a frequent concern of Dexter that there will be signs of a serial killer that will point to the baby following in his footsteps. This is seen when the baby inflicts harm on another child similar to how his father cuts his victims on the cheek, and when his repetition of the phrase "Bye-bye" sounds similar to "Die-die." to Dexter. A psychologist comforts Dexter with the knowledge that the baby appears to be fine; however, Harrison shows signs at the end of the season that he might indeed follow in his father's footsteps.
By the sixth season, Harrison has grown old enough to enter preschool by the premiere. Now being babysat by Batista's sister Jamie, he does not seem to have endured any permanent psychological impact from his mother's death. He is often seen playing or being read to by Dexter, who calls him a "light" to his "darkness". Harrison undergoes an appendectomy in the fourth episode, causing Dexter to have a crisis of faith.
In season 7, Harrison is missing from a few episodes while he is staying with his half-siblings, Astor and Cody, in Orlando with their grandparents. Harrison appears to bond some with Dexter's then-girlfriend and fellow serial killer, Hannah McKay.
Doris Morgan 
- Kathrin Lautner
Doris Morgan is Debra's biological and Dexter's adoptive mother. She died of cancer when Debra was 16. Doris is seen briefly in a flashback in Season 1, seen in a picture that is replicated by the Ice Truck Killer and another episode urging her husband to contact Dexter's biological father for a blood transfusion, and again in another flashback in Season 2, suggesting that Dexter be tested by a psychologist.
Laura Moser 
Laura Moser is Dexter and Brian's biological mother. She was involved in the drug trade and had a habit of painting her fingernails in different colors. She and three others were sawed into pieces in a shipping container as her two sons watched, causing their murderous urges. In the second season, it is revealed that Laura had an affair with Harry Morgan and was working as a police informant, trying to get evidence against Santos Jimenez's boss. She is not named in the books and no such revelation is made. Laura appears in Season 3 during two of Dexter's visions of Harry. While Dexter is tracking a victim on a cruise, she sits with Harry as if they were vacationing together, much to Dexter's discomfort. In the season finale, she appeared, again with Harry, at Dexter's wedding appearing to be happy for her son. Her mugshot was also briefly seen on Debra's desk as she investigated her father's infidelity. When Debra's investigation of another informant (coincidentally the file before Laura's) leads her to discover her father having multiple affairs with informants, she angrily gives up on her search; Dexter takes this opportunity to shred Laura's file and her photo, but is unable to go through with the photo ("I can't let her be cut up again") and keeps the upper half in his desk. Despite Dexter's efforts, Debra and a former informant locate Laura's house, which ultimately links Dexter to Laura, and to Brian.
Brian Moser 
- Christian Camargo
- Brandon Killham (child)
Brian Moser (alias Rudy Cooper, moniker The Ice Truck Killer) is Dexter's biological older brother and the main antagonist of the first season.
As children, both brothers witnessed the chainsaw murder of their mother, Laura, and afterward were left for two days with her body in a shipping container until the police found them, a memory that lay buried in Dexter's subconscious for years until a therapist unknowingly reawakened the memory.
In the aftermath of the killings, Harry Morgan, the officer-on-scene, adopted Dexter, while Brian was left in the state's care. Brian believed that Morgan did not want anything to do with him because he saw him as a "fucked up kid". Brian suffered severe psychological trauma due to the experiences in the container and was left in a mental institution, where over time he became a violent psychopath, resulting in him also becoming a brutal murderer, even more dangerous than Dexter himself.
Upon being released, he went underground, refining his ability to kill and taking on the identity of a plumber he killed (Rudy Cooper) as an alias, all while searching for his brother. Eventually, Brian not only discovered Dexter's location and history upon being separated, but also discovered he was similarly "damaged"; upon learning this, Brian immediately plotted to reunite with Dexter for the purpose of killing people side-by-side.
Brian went to Miami, working as a prosthetist and murdering prostitutes as the "Ice Truck Killer". At some of his kills and at Dexter's apartment, Brian left clues to his and Dexter's past. Brian developed a relationship with Debra, Dexter's foster sister, while treating one of his own victims, Tony Tucci. As Debra fell in love with him, he used Debra as a means to get closer to Dexter. The week before Dexter was informed of the death of his biological father (Joseph Driscoll) and met Brian Moser for the first time, Brian disguised himself as a cable repair man and visited the house of the deceased man. At the end of the ninth episode of the first season it was implied that Brian had murdered Joseph Driscoll while in disguise by injecting insulin. The body was cremated before Dexter could find any evidence of murder. Brian began slowly to show more of an interest in spending time with Dexter. When Brian talked to Dexter about possibly marrying Debra, he lied about a cut on his lip. He told Dexter it was a lab accident, but in reality he received the cut while attacking and nearly killing Angel Batista. This led Dexter to the realization that Brian was the Ice Truck Killer. Brian immediately kidnapped Debra, which led to the police suspecting his involvement in the Ice Truck Killer case.
After searching Brian's apartment, Dexter tracked him down at the site of their childhood home, where Dexter recalled that they were brothers. Brian told Dexter his history after their separation, and tried to convince Dexter to kill Debra in the same manner that he killed his victims. Dexter refused, leading to a fight between the two as the police arrived. Brian escaped the house and disappeared.
Brian later attempted to kill Debra when he thought she was staying at Dexter's apartment, but instead fell into a trap set by Dexter, who then brought him to the cooling room where Brian committed his murders. After a few choice words between them, a heartbroken Dexter slashed Brian's throat and drained his blood into a bucket, killing him in the same manner as Brian did his victims, but making it appear to the police that Brian killed himself.
Brian's death left Dexter in great pain, to the point that he began making mistakes in his killing rituals. In early episodes of the second season, Brian appeared to Dexter as a vision and, in the end, Dexter learned he needed to let go of his feelings about his brother before he could move on with his life.
However, these visions return after he avenges the murder of Brother Sam, becoming a darker advisor parallel to his father. After an escapade in Nebraska in which Dexter confronts a seemingly-murderous Jonah Mitchell, Dexter's adherence to the Code of Harry and Jonah's guilt lead to Dexter reaffirming his faith in his father, who returns at the end of the episode.
In Darkly Dreaming Dexter (unlike in the TV series), Brian does not use the name Rudy Cooper and does not get romantically involved with Debra. He is described as resembling Dexter so strongly that, upon seeing an image of Brian with dismembered corpses, Dexter and Deborah are convinced that Dexter is the murderer; when they meet, Dexter notes that Brian is an inch or two taller, thicker through the shoulders and chest, and paler. He first meets Dexter face-to-face in a shipping container located in the same place as the one where their mother was murdered, with Deborah tied up and ready for Dexter to kill. Rather than killing either Deborah or Brian, Dexter lets him go, whereas he kills him in the TV series, recognizing that it is the only way to save his sister. Their professions differ as well; the books have Brian working with imports, while the series has him as a prosthetic surgeon. The age gap between Brian and Dexter is given as one year in the book and two years in the television series. In the books he is known as the Tamiami Slasher; in the show, he is known as the Ice Truck Killer. Brian returns in Dexter is Delicious after learning of the birth of Dexter's daughter. He introduces himself to Dexter's family, and he worked for the cannibalist coven that would later lure Dexter and Deborah into a trap, later saving them from the cannibals.
Joe Driscoll 
Joseph "Joe" Driscoll was the biological father of Dexter. His exact relationship with Laura Moser is not made clear, nor it is specified whether he was Brian Moser's father as well. Joe was in the U.S. Army and served in the Vietnam War, and later became a drug-addicted criminal, at some point being imprisoned. When Laura was exposed and murdered for being involved with the police in their attempts to bring a gang to justice, Joe went underground, abandoning his sons to the justice system, and settled in Dade City, Florida. This was why "Joe" adopted an alias; his real name remains unknown. Dexter does not know or remember anything about Joe. He later finds out he is an expert bowler and recovered from his drug abuse.
Harry Morgan, Dexter's adopted father, was able to track Joe down, and convinced him to give a transfusion of his rare blood when Dexter was injured in an accident and needed surgery. Joe then received a handmade thank-you card, which he apparently treasured. His will named Dexter as executor and sole heir.
Joe met his death at the age of 60, when Brian (now the Ice Truck Killer and going under the alias of "Rudy Cooper"), who knew it was the best way to reconnect with his long-lost brother, tracked Joe down and got access to his house while disguised as a cable repairman. Brian was able to slip Joe a sedative, and then injected him with insulin, causing Joe to have a seizure and die of cardiac arrest.
When Dexter, Rita, Debra (Dexter's adopted sister) and "Rudy" came to sort out Joe's house, Dexter took blood samples of himself and Joe and sent them to Vince Masuka to perform a DNA test, which came back as a match. Dexter suspected that Joe's apparent heart attack was actually murder. However, the body was cremated before Dexter could obtain proof, and thus he never found out what "Rudy" had done. Rudy and Dexter stole Joe's ashes and scattered them at the entrance of Joe's favorite bowling alley.
Joe and Dexter, when compared, are shown to have great physical resemblance, and Dexter also inherited his father's bowling skill.
Gail Brandon 
Gail Brandon is Rita's mother, Cody, Astor and Harrison's grandmother and Dexter's mother in law. Gail is a former public-school teacher who was fired by the school board due to "philosophical disagreements" (she disapproved of what she saw as the gradual acceptance of mediocrity in the way schools treated children and made her feelings well-known). She has extremely high standards, making her judgmental of her daughter and her grandchildren. After she arrives, she becomes suspicious of Dexter, claiming that he is hiding something. She distrusts Dexter, and believes him to be a drug addict, and believes Rita is repeating her mistake with Paul by getting involved with another addict. Near the end of Season 2, her attitude causes Rita to break off her ties with her mother and force her to leave her home and return to Michigan, not wanting her children to be exposed to her the way she was. In Season 3, Gail refused to attend Dexter and Rita's wedding, claiming that because she had started teaching again she was too busy. She did, however, send a scathing card expressing her hope that Rita's third marriage would be "the charm", though Rita is hiding that fact in stating that her mother means the third child. (It is also revealed that her surname, and therefore Rita's maiden name, is "Brandon").
Paul Bennett 
Paul Bennett is Rita's abusive and manipulative ex-husband and the father of Astor and Cody. After his release from prison, where he was sentenced for nearly beating Rita to death, he tries to rekindle a relationship with his children, though he still harbors disdain for Rita. Paul (correctly) suspects Dexter of framing him for the drug charge that sent him to his latest stint in jail. After a short while in a federal prison, he loses hope after failing to convince Rita of Dexter's plan to frame him. Rita later tells Dexter that he provoked a fight shortly thereafter with another inmate, who beat him to death with a pipe.
In the book series, Rita's ex-husband is mentioned but never makes an appearance (or is named) since he is dead before the events of the books. In the TV series, by contrast, Paul appears in the second half of the first season and in the first episode of the second season, and his interactions with Dexter lead to a key plot point. In the books, he beat Rita's children as well as beating and raping her; in the series he clearly loves his children, the two of them appearing ignorant of the full reasons why their parents split up, and his violent tendencies are directed toward only Rita, though she says that "she bore his abuse so they wouldn't have to", suggesting that he would have beat them too. In the TV series, it is Astor who finally calls the police on Paul, while in the book series Rita does when he begins to beat Astor and Cody as well.
Bill & Maura Bennett 
Bill & Maura Bennett are Paul's parents, living in Orlando. They are quite the opposite of their son, providing love and comfort to both Rita and her kids after her separation from Paul. First appearing (played by unknown extras) in the season four finale, taking their grandchildren to Walt Disney World, they return to Miami in the season five premiere, only to learn of Rita's murder.
After Rita's funeral, as Astor decides she wants to live with her grandparents, rather than Dexter, Bill and Maura bring both their grandchildren with them back to Orlando. Although they are not Harrison's biological grandparents they have shown love and have cared for him when Dexter needed them to.
Additional characters, introduced in season 1 
Camilla Figg 
The Camilla Figg of the books and television series differ significantly. In the books, Camilla Figg is a young member of the forensics team who has a crush on Dexter. She is later killed by Bernard Elan, who attempts to use her obsession with Dexter to make him suffer.
In the television series, Camilla is older than Dexter, and had a close relationship with his father. She was a records supervisor at the Miami Metro Police Station. She and her husband, Gene, were good friends with Harry Morgan and his wife. She also knew Dexter and Debra while they were children and was still very good friends with Dexter who often brought donuts to her workplace at the records room. She knew far more about Dexter's past than she let on to him and was even willing to say that the case files had been destroyed, in order to protect Harry's secret. On Harry Morgan's orders, she destroyed the file of the crime scene where he had found the young Dexter. Near the end of the second season, she informs Dexter this will be her last year working as she is retiring. In Season 3, it is revealed that she has terminal lung cancer just like her husband, who died one year earlier, as they were both smokers, and in her deathbed Figg reveals that she knew that the Ice Truck Killer was Dexter's brother as she read his report before destroying it. During her agony, she frequently asks Dexter to bring her the "perfect key lime pie" until he realizes it is meant as a euphemism for euthanasia: she was asking for a poisoned pie. Dexter complies to her wishes, but before she dies he tells her that it was he who killed his brother. She surprises him by smiling and telling him that "it's good you did" right before she dies. She is the first victim of Dexter's who wanted to die by his hands as well as the first victim he felt he showed mercy towards.
Tom Matthews 
Tom Matthews is a high-ranking Miami Metro PD police official who serves as its deputy chief. Previously, he served as commanding officer of Miami Metro PD Homicide Division and the immediate superior of Lieutenant María LaGuerta. Before this, he was a lieutenant himself, serving as superior of, and best friend of, Harry Morgan. When Harry committed suicide, apparently having burned out from witnessing too many failures in the justice system, Matthews used his influence to bury any indication of suicide, and fulfilled a promise he made to Harry to look after Dexter and Debra; which is what he has done to this day.
Matthews is portrayed as having flaws: nominal racism and serious political ambition, neither of which are ever shown in the novel series.
While having originally promoted LaGuerta, he frequently clashed with her, trying to keep her focused on hunting the Ice Truck Killer correctly. Later, however, he fails to take his own advice, as, when Neil Perry was mistakenly arrested, and Matthews received all the praise, he went so far as to try to bury any evidence to the contrary. Seeing the investigation was being jeopardized, LaGuerta revealed that several mistakes during the Ice Truck Killer case had been made, landing Matthews in a world of trouble. Due to the fact he was friends with both the police commissioner and the review board, Matthews escaped punishment and, having been personally embarrassed and wanting vengeance, Matthews laid all the blame on LaGuerta, and so gained approval to install Esme Pascal as the new lieutenant; to supervise her. This proved temporary, however, having later seen Esme break down and regained his confidence in LaGuerta's abilities, Matthews restored her to her previous position.
Matthews' latest political effort, applying for the position of deputy chief, succeeded after Matthews used the fame of successfully ending the Bay Harbor Butcher case to propel himself to that position. Matthews did not appear in Season 3, but re-appeared in Season 4, having succeeded in being promoted to deputy chief, personally invested in the investigation surrounding Frank Lundy's death, and Debra's shooting. After LaGuerta and Batista reveal their relationship, he initially wants to transfer Batista out of Homicide to avoid complications during a trial. Eventually, LaGuerta and Angel both agree to end their relationship to continue working in Homicide; and while accepting this, Matthews warns them that there will be serious consequences if their relationship continues. After revealing a video of LaGuerta and Batista kissing, LaGuerta calls Tom out, asking if it was because of her gender or race that he seems to have a grudge against her. Matthews simply replies he has a grudge against her because of her arrogance. In order to circumvent a reprimand from higher up, and also as a result of their deepening feelings for one another, LaGuerta and Batista secretly get married with Dexter as witness.
In the sixth season premiere, Matthews oddly has promoted LaGuerta to captain, which many characters note as unusual. After the ceremony, however, it is shown that LaGuerta had found a "little black book" of a brothel with Matthews' name in it, trading the evidence for her promotion. Accordingly, her promotion left the lieutenant position open, which LaGuerta attempted to secure for Batista. However, Matthews declares Debra a more suitable candidate, being young and famous after a shootout at a restaurant in which Debra and Quinn were involved was recorded and posted online. LaGuerta and Batista both believe that he did this in vengeance, though little was proven. His prostitute-hiring tendencies leads to a call girl dead from a heroin overdose, which while not his fault, led to LaGuerta attempting to cover up the no-fault crime scene claiming the low clearance rate as unacceptable. However, Debra continues to search after a visit from the call girl's parents, leading to her discovery of Matthews' involvement. LaGuerta used the information on Tom and betrayed him and had him forcibly retired by the board when she told them. Tom however, believed it to be Debra who sold him out but she stated she never would do that and Debra would confront LaGuerta for doing such a low tactic, knowing full well she did it for her own personal gain. As such, LaGuerta will now take over Tom's position possibly as Deputy Chief.
After much absence, Tom is finally brought back during LaGuerta's suspicion that Dexter is the BHB. He is seen on his boat drinking scotch greeting LaGuerta as she confinds her suspicion that the BHB is alive and well. Tom doesn't believe her, stating the evidence was all against Doakes, but seems to show surprise after hearing a blood slide found at Travis Marshalls' church site. Though reluctant at first, Tom decides to help after discovering LaGuerta was the one who sold him out to the board and shows his anger despite LaGuerta stating he started it. He intends to help for his own reason for his 40-year pension despite LaGuerta's displease at the prospect.
As they dig into the case, the revisit the cabin Doakes died in and discover that Santos Jimenez had rented the cabin, prompting Tom to realize who he is and reveals to LaGuerta Jimenez is responsible for Dexter's mother's death and changing Brian, Dexter's brother, into becoming the ITK. This causes LaGuerta to, after hearing Jimenez's disappearance and Dexter's background, immediately starts to believe Dexter set Doakes up and he is the true BHB. Tom however, refuses to believe her and keeps LaGuerta to question him stating he'll do it having known Dexter since he was a boy.
As Tom talks personally to Dexter, he confides how LaGuerta believes he is the butcher (though Dexter is able to see that Tom also believes it in some way). Dexter then tells him about a boat Doakes once had to lead him off the case which has Tom believe him. He tells LaGuerta about this and she doesn't believe him stating she would have known if Doakes had a boat. They find a tackle box from the old cabin and find a key to a marina and, believing it to be Doakes's old boat spot, search the area and find several sheets of plastic, knives and one with degraded blood on it with Doakes's fingerprints on it. This causes Tom to immediately believe Dexter, but LaGuerta still believes other wise stating Dexter could have planted (which is actually true) it despite Tom's refusal and that Maria should move on. She says she'll keep her word and give Tom his pension and late is visited by Dexter where the two make amends for each other's suspicions.
Esme Pascal 
Lieutenant Esme Pascal is a Haitian American police officer who becomes well-respected (considered a "real up-and-comer" by Captain Matthews) after being shot in the line of duty but recovering. When LaGuerta oversteps her authority and embarrasses Captain Matthews with new developments in the Ice Truck Killer case, Matthews brings Pascal in to replace her. Pascal remains Lieutenant of the department well over a month after the end of the case, earning the trust of the police officers and friendship of LaGuerta, but soon begins to crack under pressure when she starts to experience personal problems with her fiancé Bertrand (portrayed by Kiko Ellsworth). She suspects him of adultery on little real evidence, which gradually casts doubt on her rationality. Her obsession becomes so strong that she uses department resources to investigate him, tracking his phone calls and having the forensics department do tests on his shirt (stating it had the smell of another woman on it). As a result of this, Captain Matthews becomes increasingly concerned that he had made the wrong decision in replacing LaGuerta with Pascal, but LaGuerta remains stalwart, apparently standing behind Pascal on principle of loyalty. Captain Matthews is impressed by LaGuerta, believing her to have abandoned her political scheming, and returns control of the Homicide Division to LaGuerta. It is later revealed that LaGuerta manipulated the whole incident, and was the one having an affair with Pascal's fiancé in the first place to try to get rid of Pascal and get her old job back.
Additional characters, introduced in season 2 
Frank Lundy 
Frank Lundy was a high-ranking and illustrious FBI Special Agent, serving as one of their manhunters and the Bureau's top agent. Lundy was recruited by Cpt. Matthews to lead the task force dedicated to identifying and arresting the Bay Harbor Butcher.
Lundy was cool, calm, confident, and incredibly intelligent and learned about the criminal mind, often finding the important case evidence the frustrated Miami PD normally overlooked. Lundy was infamous with police agencies due to him breaking impossible high-profile criminal cases (e.g. the real-life Green River Killer and the DC Sniper). On a personal level, he had a wife, who died due to cancer, and a daughter. He is fond of classical music. Unknown to anyone else, Lundy had secretly devoted 15 years of his career to hunting down the "Trinity Killer", tracking him and seeing him as the most elusive serial killer he has ever encountered.
During the hunt for the Bay Harbor Butcher, Lundy became dangerously close to finding out Dexter is the Butcher he is seeking, and at the same time becomes involved in a relationship with Debra, helping her get over her left-over chaotic emotions from her time as the prisoner of the Ice Truck Killer. In the end, Dexter outmaneuvers and frames Doakes as the Butcher, leading Lundy to lead the entire police forces in a full-scale manhunt to find Doakes. After Doakes is killed in a seemingly accidental explosion, the case is considered closed and Lundy moves on to find another serial killer in Oregon.
Lundy retired from the FBI some time later, but continued his mission of hunting Trinity. After tracking him to Miami, Lundy, no longer possessing access to the full resources of the FBI, asked for Dexter's, and later Debra's, help in pursuing the Trinity Killer. Eventually, Lundy began to close in on Trinity, going so far as to predict where and when the murders would occur, as well as identifying Arthur Mitchell (albeit unnamed) as a suspect. In the course of the investigation, Lundy and Debra rekindled their relationship, but shortly afterward, both Lundy and Debra were shot by an unseen gunman. Lundy bled out and died from his injuries.
Dexter mourned Lundy's death, having seen him as a "worthy adversary" and feeling that he deserved a more fitting end. Debra, however, blamed herself for what happened. It was originally believed the Vacation Murderers were responsible, but Dexter suspected Trinity. Debra's own investigation, however, revealed that neither the Vacation Murderers nor Trinity were the shooter. Quinn's girlfriend, Christine Hill, who was revealed to be Trinity's illegitimate daughter, was revealed to be the shooter.
Gabriel is a writer who becomes Debra's first boyfriend after Rudy Cooper/Brian Moser. He first appeared in the episode "Waiting to Exhale" where he met Debra Morgan at a workout gym. Noticing that Debra was checking him out, he offered to help her start training with a punching bag. This did not bode well; while taping up her hands, Debra had a flashback of her abduction by Rudy Cooper. She quickly ran from the scene with little explanation. She apologizes a little later however and they start going out, she takes him back to Dexter's flat where she handcuffs him to the bed on the grounds that the last person she slept with tried to kill her and Dexter walks in on them by accident. She begins to wrongly become suspicious of him and goes as far as searching his belongings and checking his e-mails. She finds an e-mail concerning a story he has written called "The Ice Princess" and believes that he is writing a story about her and leaves him accusingly. She then finds out that he is trying to be a children's writer and apologizes. They go on several more dates but breaks up with him due to her increasing attraction to Frank Lundy.
Lila West 
Lila West, who goes by the pseudonym Lila Tournay, is Dexter's Narcotics Anonymous sponsor and the main antagonist in Season 2. Originally from England, she works as an artist, often using stolen items in her work. Dexter has an affair with her, leading to his breakup with Rita. She confesses to Dexter that she went sober after unintentionally killing her ex-boyfriend while intoxicated. She is in fact a sociopath who hangs out in support groups in an attempt to feel emotions she is otherwise incapable of. She immediately sees through Dexter's "mask" and becomes obsessed with him, believing him to be her soulmate.
She sets her own loft on fire and helps Santos Jimenez attack Dexter, believing that she and Dexter are closest in times of crisis. When she breaks into Rita's house, afraid that Dexter might have gotten back together with her, Dexter immediately ends their relationship.
In retaliation, she seduces Angel Batista, has rough sex with him and then accuses him of rape, having taken Rohypnol immediately after sex so it would look like Angel had drugged her. Enraged, Debra asks Lundy to run a background check, discovering Lila is working under an alias. A fingerprint analysis turns up Lila's real surname (West) and that she has been illegally living in the United States on an expired visa. Debra confronts her and demands that she leave the country or be deported. Lila, following Dexter and watching him on his boat with Rita, Astor and Cody, breaks into his van, takes his GPS device and finds the address for Jimenez's cabin. Arriving at the cabin, she finds Doakes caged inside and, upon learning from him that Dexter is the Bay Harbor Butcher, decides to protect Dexter and ignites a propane tank inside the cabin, killing Doakes.
After finding evidence that Lila killed Doakes, Dexter has the justification he needs for killing Lila. Dexter gathers his tools in a bag and goes to Lila's apartment under the guise that they will leave town together. Dexter's plan is foiled when Debra shows up and Lila walks in on them. Lila leaves the apartment, taking Dexter's bag with her. Upon examination of the bag, Lila learns of Dexter's plan to kill her.
She abducts Astor and Cody, and uses them to lure Dexter inside her loft, and sets it ablaze again. Dexter and the kids narrowly escape, and Lila flees Miami. While living in Paris, Lila checks her mail and discovers a postcard from Miami with Doakes' picture on the back. Dexter emerges from the shadows, injects Lila with a spinal epidural (so he can speak his piece to her while also ensuring that her death is painless) and lays her down on the couch. Lila pleads for her life and tells him that she killed Doakes for Dexter's sake. Dexter asks if she tried to kill Rita's children for his sake as well, thanks her for helping him embrace what he is, and then stabs her through the heart. He wraps her corpse in a plastic garment bag.
Lila is so far one of the few main antagonists who was not given an official nickname. However, she has been called a "vampire" by Debra as an insult, alluding to her skin, which according to Debra is "pale like a fucking corpse". She was also known for setting things on fire, but never got an official nickname for that reason either. She was mentioned once by Rita and once by Vince in Season 4. Before Hannah McKay, she was the only female main antagonist throughout the series.
FBI Deputy Director Max Adams 
Max Adams was the FBI Deputy Director who pushes Lundy aside during the investigation of the Bay Harbor Butcher. He appeared in two episodes during the second season.
Francis is a friend of Debra, and the successor to Camilla Figg as the records supervisor of the Miami Metro Police Station. She first appears in the episode "The Dark Defender", and has appeared in a total of 7 episodes as of the season 5 finale.
Additional characters, introduced in season 3 
Miguel Prado 
Miguel Prado was a senior Assistant District Attorney, infamous for his harsh enforcement of the law, making him powerful, influential and popular with the regular police and citizens of Miami, and the main antagonist of Season 3. He has a romantic history with Lt. LaGuerta and he comes from a well-connected family, about whom he cares greatly. As such, Prado takes it hard when his younger brother Oscar is found dead in the house of a drug-dealer nicknamed "Freebo", and even worse when it was found Oscar was a drug addict to whom Freebo sold and that Oscar was in Freebo's debt, making it look like he was killed for not paying his debts. Oscar was indeed battling Freebo when Dexter arrived, and while Freebo fled, Oscar was killed by Dexter himself in self-defense. Prado asks Dexter to join him at Freebo's house, where Prado expresses great appreciation to Dexter not only for helping to track down Freebo, but also for trying to understand why Oscar had been killed, and invites Dexter to attend Oscar's wake. Prado finds Freebo's hideout and goes to kill him, but finds Dexter there after already killing him. He expresses appreciation to Dexter for killing Freebo and later, gives Dexter his shirt with Freebo's blood on it as a form of mutual assurance that he will not betray Dexter. Dexter and Prado form a close bond, often drinking beer and watching television at each other's homes, and Prado becomes Dexter's first true friend. He eventually finds out that Dexter is a killer, a fact that earns great admiration from Prado. Prado even goes as far as to learn the Code from Dexter, and is the second person to witness Dexter in a kill room. With Dexter's guidance he would go on to kill a mob enforcer.
Later that same night, without Dexter's knowledge, Prado kills Ellen Wolf, a defense attorney who was trying to ruin his career by claiming some mistakes he made in his cases were "proof" of Prado's claimed "illicit prosecution tactics, which include witness tampering and deliberately ignoring evidence". Dexter was disappointed with Miguel's violation of the Code and digs up Wolf's body for the police to find to teach Prado a lesson. Prado seems to have learned his lesson after a talk with Dexter, but Dexter later begins to doubt the authenticity of Miguel's friendship when he learns Miguel used exactly the same language he used in a talk between them in a talk with Rita about trust. Dexter's suspicions are confirmed when he examines the shirt Miguel gave him after the murder of Freebo. The blood on the shirt is in fact cow blood, and Dexter realizes that Miguel has been manipulating him all along. After a game of one-upmanship with regard to Ellen Wolf's murder case, with Miguel threatening to expose Debra Morgan's relationship with the CI Anton and use his position as ADA to make trouble for Dexter, Dexter decides to kill Miguel using the MO (Modus Operandi) of a sought-for killer, just as LaGuerta discovers Miguel killed Ellen. When Miguel discovers that LaGuerta is investigating him, he plans to kill her, but Dexter discovers what Miguel is planning, traps him at LaGuerta's house when Prado goes there to kill her and kills Miguel by garroting him, but not before telling him that he killed his brother. The entire city of Miami mourns the passing of Miguel Prado, a hero to all, and so the City Council votes to name the city's main freeway interchange after Miguel. This greatly upsets LaGuerta, who is ready to accuse Miguel of murdering Ellen Wolf. Dexter is able to convince her that doing so would only hurt Miguel's family and the Cuban Community, and even then there is a high chance that nothing could be proven, so she drops it.
It was later discovered through Miguel's brother, Ramon, that he also lied about the story of defending his family from their abusive father where it was in fact Ramon who did it. He stated that Miguel "always had to be in the spotlight" and that he had been covering up for Miguel for years.
Miguel is the first main antagonist to die before the last episode of a season.
Ramón Prado 
Ramón Prado was one of the three Prado brothers, and was a county sheriff with the rank of lieutenant. He was married to Sara (portrayed by Paula Miranda), and the couple had one son, Carlos (portrayed by Aramis Knight) and a daughter in pre-school.
Ramón and Miguel were both devastated at Oscar's death, with Ramón steadily becoming more and more unstable with time, frustrated with the Miami Police Department's handling of the murder case. Initially, Ramón attempts to keep working, though he steadily slides into alcoholism. In an effort to help his brother, Miguel tries to convince Dexter to tell Ramón about Freebo's death, but is convinced otherwise when Ramón, with a little provoking from Dexter, attacks an innocent person in front of his brother. His increasing recklessness eventually drove him to the point of kidnapping and torturing one of Freebo's clients, which in turn got him arrested by Debra and Quinn. To avoid a prison sentence, Ramón, largely disgraced in the eyes of his Miami Metro PD colleagues, unwillingly accepted the offer from the police union of early retirement with benefits, and so surrendered his gun and badge.
After Miguel was seemingly killed by The Skinner (really Dexter to stop his murderous rampage), Ramón, desperate for someone to blame, went out of control. Having been taken on earlier as a bodyguard for Miguel against Dexter (whom he had always had a slight distrust of), and so was driven to hunt Dexter. Dexter tried to find Ramón without success, but instead Ramón showed up in a drunken rage at Dexter and Rita's rehearsal dinner, and pushed off Dexter's calm attempts at discussion. He instead drew his pistol and jammed it in Dexter's face, but was stopped and arrested by Batista and Debra.
Even though Harry recommended Dexter kill Ramón out of mercy, Dexter, instead, elected to speak to him while he languished in the county jail. Dexter's words made Ramón understand and face his own demons, and brought peace between them. The end result was Ramón finally coming out with the source of all his pent-up anger, frustration and distrust: Miguel. All of his life, Ramón remained in his famous brother's shadow (and even helped to build it—such as knocking their abusive father down the stairs and letting Miguel take the credit), that, while Miguel had the appearance, charm and even the intelligence, Ramón had the strength and spent his whole life holding Miguel's legend together. Now that Miguel was dead, Ramón let go of his harsh behaviours so as to not pass it on to his beloved son and daughter.
As one last favor from his famous brother, Ramón was released a matter of days later.
Anton Briggs 
Anton Briggs is a pot-smoking guitarist who is a confidential informant (CI) for Detective Joey Quinn. Quinn helps Debra out by giving her Anton's information in hopes that he will help her find a lead to Freebo, to which he obliges. Debra continues to meet with Anton to help her find information about both Freebo and later The Skinner because of his connections. Debra becomes close to Anton and eventually develops a romantic relationship with him, which occasionally clouds her judgment. She also finds out that Anton is not officially a CI because Quinn was trying to do him a favor by keeping it off the books. The police end up using Anton as bait in a possible trap for The Skinner, but Debra objects. The Skinner kidnaps Anton and removes two strips of skin from his back before Debra and Quinn rescue him. After Debra finds out that her father cheated on her mother with a CI, she becomes wary of Anton and they eventually break up. At the end of Season 3, they get back together when Debra realizes (with the help of Dexter) that her father Harry would have been so proud of her for being a great cop and getting her detective shield, regardless of her relationship with Anton. At the start of Season 4, their relationship starts to move forward just as Lundy returns and admits he still has feelings for Debra. Debra, who had begun to feel claustrophobic in her relationship with Anton, eventually realizes she returns Lundy's feelings and sleeps with him. This results in Anton and Debra breaking up and Debra leaving his place after she admitted she slept with Lundy to Anton. Anton visits Deb in the hospital, where she officially ends their relationship for good. He has not been seen since.
Yuki Amado 
Yuki Amado is the Internal Affairs officer who was pressuring Debra Morgan to give her information on Joey Quinn, promising to help her become a detective in return. Debra has not yet agreed and has been shown to become extremely irritated with how much Yuki is forcing her, to the point that Yuki is giving Debra orders as if she did agree to help the case. After being confronted by Debra that Quinn told her that it was just a personal grudge of hers, she states that he is lying and is investigating him because of his alleged tendency to cut corners.
Sylvia Prado 
Sylvia Prado is Miguel Prado's wife. She is a real-estate agent and becomes close friends with Rita, even hiring her as her assistant. Later she confides in Rita that she suspects her husband is having an affair. After a miscommunication with Dexter, Rita believes that Prado is cheating on his wife with LaGuerta, which she later tells Sylvia when trying on bridal outfits. Due to bad timing, she sees her husband leaving LaGuerta's house and she believes he has been cheating on her all this time and forces him out of her house. Sylvia was devastated when Miguel was killed, apparently by The Skinner (really Dexter).
Ellen Wolf 
Defense Attorney Ellen Wolf is Miguel Prado's main rival. Ellen believes Miguel (who she derides as a "fascistic prosecutor") bends the rules to put innocent people in prison while Miguel believes Ellen helps guilty people get off. Miguel believes that people like Ellen are the root of the problem that Dexter tries to solve through killing. However, his opinion of her seems to change favorably when Wolf betrays her client, a murderer named Albert Chung. Later, after participating in one of Dexter's murders, Miguel realizes he's capable of cold-blooded killings himself, comes to Wolf's house alone and murders her. Wolf was a close friend of Lt. LaGuerta, who is devastated upon Wolf's death. LaGuerta quested to solve the crime, and in the end discovered Miguel's actions. She initially vowed to tear what life he left behind apart (Miguel had recently been killed by Dexter, although everyone thought it was the Skinner), though Dexter makes her understand she would be hurting Prado's family, the local community who supported and admired him and the city at large, and there was no guarantee she would find anything. In the end, LaGuerta accepted Dexter's advice and closed the case, keeping Prado's actions a secret and saying goodbye to her friend.
Jorge Orozco 
Jorge Orozco, alias George Washington King, was one of the primary antagonists of Season 3. Conscripted into the Nicaraguan army, he rose to the rank of Captain in the Resistencia Nicaragüense, heading an interrogation unit. Orozco tortured and killed people for a living, earning the nickname "The Blade". His time in the army left him with a deep need for respect. Orozco left the army and moved to Miami, founding and becoming boss of his own tree-trimming company.
When Freebo, a petty criminal, disappeared (killed by Dexter) while in debt to Orozco, Orozco resolved to hunt him down and make him pay for his affront, though Dexter saw this as a transparent excuse for his own sociopathic needs. As Debra Morgan met with Freebo's old associates in an attempt to find him, Orozco trailed her, covertly watching their homes under the cover of trimming their trees, and eventually kidnapped each of them, tortured them for information and killed them, taking a patch of skin from each victim, for which he was dubbed "the Skinner".
Upon questioning, Orozco deflected attention to one of his violent employees; but when the employee learned Orozco was involved, he had a near-panic attack, causing the police to focus on Orozco. The police then set up Anton Briggs, a former confidential informant, as bait by making him seem to know where Freebo was. Orozco kidnapped and tortured Briggs, but Debra and Joey Quinn interrupted, saving Briggs's life and forcing Orozco to flee.
The man-hunt continued, escalating when Dexter framed Orozco for ADA Miguel Prado's death (in reality by his own hands), but Dexter was ultimately captured and abducted by Orozco, having been told by Prado that only Dexter knew where Freebo was. Orozco intended to torture and skin Dexter for information, but instead Dexter effectively stripped him of his control (by revealing the truth that Freebo was long dead), then broke free. In a brutal fist-fight, Dexter broke Orozco's neck, killing him. The police arrived, having tracked down Orozco's hideout, but Dexter avoided detection by dropping Orozco's body in front of one of the speeding squad cars, making it look as if the collision caused the death. Getting hit by the car skins his face; Debra joked that "what goes around comes around".
Barbara Gianna 
Barbara Gianna, a detective with Miami Metro Police Department's Vice Division, was the girlfriend of Sgt. Batista. According to Masuka, her work has made her a "Wikipedia of perv". She is attacked and beaten by a would-be "john" and Sgt. Batista has Dexter run her keys for blood and DNA. She appears suspicious of Sgt. Batista's rapid devotion to her and subsequent good behavior, considering she met him while he was "trolling for hookers". In the beginning of Season 4, it is revealed that they have broken up. Angel credits this to them "wanting different things".
Additional characters, introduced in season 4 
Arthur Mitchell 
Arthur Mitchell is the main antagonist of the fourth season. He is an unassuming suburbanite man who has been living a double life as one of America's most prolific and deadly serial killers, dubbed the Trinity Killer by FBI agent Frank Lundy.
Christine Hill 
Christine Hill is a Miami Tribune reporter who meets Joey Quinn at the scene of Lisa Bell's murder. She starts a relationship with Quinn, often seducing classified police information out of him, including the Vacation Shootings, and the return of Frank Lundy to Miami. The police use her to help catch the Vacation Murderers. It turns out that Christine is the daughter of Arthur Mitchell/Trinity, and is also the shooter of Frank Lundy and Debra. She also reveals that she saw Arthur commit his first murder, and she shot Lundy to prevent Arthur's arrest. The police find out the biological connection and arrest her. She did not confess, however, until Mitchell angrily tells her that he wishes she had never been born. Devastated, Hill confesses to killing Lundy to Debra Morgan, then shoots and kills herself.
Elliot becomes the neighbor of Dexter and Rita, after moving in with their family following their wedding. Recently having separated from his wife, he's now a single father, and becomes friends with the Morgans, much to Dexter's annoyance. Even though he has a new girlfriend, Kate (portrayed by Marisa Petroro), Elliot eventually develops a romantic interest in Rita. During Thanksgiving he shares a kiss with her, as witnessed by Masuka. When Dexter eventually finds out, he responds with knocking Elliot down.
After Rita's death, he is interviewed as a potential witness and suspect, but is cleared. Later, he apologizes to Dexter for kissing Rita. Later, he meets Lumen Pierce while she is staying at Rita's now-unoccupied house.
Sally Mitchell 
Sally Mitchell is the wife of Arthur Mitchell and mother of Jonah and Becca Mitchell. In "Dirty Harry" and "If I Had a Hammer" it appears she has an ideal family. The entire family appears loving, is a pillar of the community, church-goers, and involved in a project to build homes for the homeless. However, this is revealed in "Hungry Man" to be a facade; Arthur is very controlling and abusive. His wife, fearing her husband, perpetually puts on a cheery facade and is willing to let her daughter continue a perceived affair with Dexter as long as Arthur remains unaware. She is last seen in tears being taken out of her home by the police when they uncover that Arthur is Trinity.
Unable to accept the reality of her husband being a veteran serial killer, Sally begins blaming her children for the loss of their lives, hoping Arthur returns to "whisk her away". The blame shifting impacts Rebecca significantly, leading to her suicide, which in turn leads to Jonah beating his mother to death in retribution. Blood-splatter indicates that the murderer was someone of Trinity's height, making people believe that Trinity had found killed them, when in reality Jonah killed his mother standing on the stairs at the same height as his father was.
Jonah Mitchell 
Jonah Mitchell is the son and oldest child of Arthur and Sally. He is a member of JROTC, plays football and at one time played baseball for his high school, which he quit; angering his father greatly. Though at first they seem to have a great father/son relationship, it is soon revealed that his father is very domineering on him and physically abusive, going as far as to break his fingers for damaging Arthur's car (a white 1968 GT-500 Shelby Mustang convertible with a blue racing stripe). Jonah tells Dexter he always comes up with excuses to explain the injuries given by his father to the school, but due to the number of injuries, is running out of excuses. He later snaps during Thanksgiving dinner and destroys his father's awards as well as smashing Arthur's sister's urn, causing him to nearly kill Jonah by strangulation but he is saved by Dexter. When Dexter is trying to find a child Arthur kidnapped, Jonah goes on Arthur's computer, discovering his father had been looking up vacant houses (although he does not know Arthur's intent for doing so). In the season 4 finale, he is seen being taken out of his home by the police when they uncover that Arthur is Trinity.
In season 5 he is seen in a store where Quinn approaches him with a composite sketch of Kyle Butler which resembles Dexter. Before Jonah can give him an answer of whether the picture is Kyle Butler/Dexter or not, Quinn is taken into custody by an FBI agent in charge of guarding Jonah while in witness protection.
In season 6, he reappears in the episode "Nebraska" as the sole survivor of his family who has been murdered by who was reported to be the Trinity Killer. While Dexter suspects that Jonah was the perpetrator, with evidence supporting, Jonah's guilt emerges in a confrontation which shows that he killed his mother for instigating his sister's suicide. No longer truly fitting the Code of Harry, Dexter tells him to forgive himself and returns to Miami.
Becca Mitchell 
Rebecca Mitchell is the daughter of Arthur and Sally. Though she is a 15 year old teenager her room resembles that of a young child. After running away once Arthur now has locks on the outside of the door and on the windows. Arthur sometimes calls her "Vera", the name of his deceased sister. When Dexter asks her about this and tries to console her, she asks him to take her away, saying she would do "anything", implying she will give him sexual favors to do so (which Dexter flatly refuses). Both Becca and her mother believe he will take Becca up on her offer, however, the latter hopes that Dexter will not allow Arthur to find out. She is last seen in tears being taken out of her home by the police when they uncover that Arthur is Trinity.
A year later, due to the unstable rantings of her mother, Rebecca committed suicide in a way similar to the first victims of her father's kills. This discovery prompts Dexter to investigate.
Additional characters, introduced in season 5 
Lumen Pierce 
Lumen Pierce is first seen after witnessing Dexter kill Boyd Fowler, a serial killer who had been keeping her captive. Despite Lumen being a witness to the murder and a clear threat to Dexter, due her not fitting Dexter's code by being innocent, he is morally obligated to keep her alive and keeps her locked up in a secluded area to give himself time to decide what to do with her. At first, Lumen is petrified of Dexter, believing that he will kill her for being a witness to his crime. Despite Dexter's constant assurances that he will not kill her, Lumen refuses to trust him. After an escape attempt, she is once again captured by Dexter. Instead of imprisoning her again, Dexter shows Lumen the bodies of Boyd Fowler's previous victims, and assures her that had he not killed Boyd, she would have been next. It is at this point that Lumen confides in Dexter and tells him that Boyd was not the only one who hurt her. It is ultimately revealed that she had been held captive for an unknown amount of time, during which she was repeatedly raped and tortured by a group of five men.
Her mentally scarring experience has left her with a desire for vengeance, and she attempts to enlist Dexter's help to hunt down and kill the remaining perpetrators. He is willing to do this for her, but suggests that she gets on with her life and leave Miami. Upon returning to her motel room, Dexter discovers that she has been attempting to track down the group of people who raped and tortured her, and has gone to kill a sex offender who Dexter, having hunted him down earlier, knows to have been wearing a tracking anklet. This revelation leads Lumen to realize she does not possess the skills or experience to discover the identities of the men who tortured and raped her and kill them. However, finding herself unable to leave Miami, she shoots a man she suspects of being one of her abusers, due to recognizing his distinctive smell. When the man escapes after being shot once in the leg, Lumen calls Dexter, who helps track down the wounded criminal, albeit reluctantly, and cautions her about killing the wrong person. Protesting innocence at first, the victim calls his co-conspirators on Lumen's cell phone, confirming her suspicion and prompting Dexter to kill him. They later meet at Dexter's house, where Lumen reveals that his death brought her a sense of peace, stating that the only way she will be able to find that peace again is to kill all of her other abusers. Dexter recognizes this as being her own "dark passenger", and agrees to help her.
Lumen turns up at the crime scene where Boyd's stocked and preserved bodies have been discovered following a traffic crash, where she is spotted by Quinn, who asks Liddy to investigate her connection to Dexter. She identifies Cole Harmon, Jordan Chase's head of security, as one of her torturers, and manages to saves Dexter from a surprise attack by Cole when Dexter attempts to gather information from Cole's house. Setting up base at the hotel where Jordan Chase is giving his seminar, Lumen assists Dexter prepare for the kill. Cole spots her in the lobby and gives chase, with Dexter barely managing to save her from Cole. Unable to extract any information from Cole, she watches while Dexter kills him. They then dispose of the body by dumping it in the ocean from Dexter's boat, and Liddy is seen photographing them.
After the police uncover DVDs of the men torturing and raping female victims, Dexter switches Lumen's DVD with a blank DVD, which he scratches in order to avoid suspicion as to why it was blank. Lumen then acknowledges that she knows what a risk he is taking by being with her, and tells him that he has been her only way through the experience. Lumen proves instrumental in getting information from Emily Birch, the first victim of Chase's team and the only other known survivor. Tilden is Lumen's first kill, as Dexter allows her to make the killing blow at her request. The two then return to Dexter's apartment, where they have sex.
Lumen and Dexter begin to plan how will they will capture Chase when they realize that they are being watched. Once Dexter determines that they are being watched by the police, he attempts to convince Lumen to leave Miami for her own safety. However, Lumen refuses to abandon him, and Dexter ultimately admits that he wants her to stay. After receiving a distressed call from Emily, who says Chase contacted and threatened her, Lumen goes to her house to reassure her, having been unable to contact Dexter. This was a trap meant for her and Dexter, however, and Jordan Chase murders Emily and takes Lumen back to camp Jordan, which he owns, and which is the location where each of the victims was originally raped and tortured. Dexter arrives at Emily's house to find that Lumen and Jordan have already left and he is able to tell that Lumen fought, albeit unsuccessfully, and swears that he will not lose her too. Dexter finds the location of the camp and shows rescues Lumen, who finally kills Chase. After Lumen and Dexter dispose of Chase's body, she admits to Dexter that she did not think they would be able to pull it off, describing it as a miracle. The next morning Lumen tearfully reveals to Dexter that her "dark passenger" has left her and that she no longer feels the need to kill. She tells Dexter that she does not want to leave, but has to, because his dark passenger has not left him. Dexter ultimately understands, and tells her that she should not be sorry that her darkness has left her, promising her that he will carry her darkness as well as his own. Dexter is devastated by her departure, but swears that he will be thankful for what she gave him, and notes that Lumen is the only person whose life has been made better by discovering his secret, "true" self (i.e., that he is a serial killer).
Cira Manzon 
Cira Manzon is a young Hispanic police officer that gets assigned to the Santa Muerte murders investigation. Debra accepts her to the team mainly due to her knowledge of the neighborhood plagued by the Santa Muerte killings. She quickly proves competent and a valuable addition to the force, despite being somewhat of a rookie and having a hard time handling some of the more gruesome murder scenes. While she has no trouble getting acceptance from her new colleagues, her optimistic outlook makes her somewhat an odd bird at the Miami Metro PD.
When an attempt to arrest the Fuentes brothers at Club Mayan gets their informant killed because of LaGuerta's bad judgment call, LaGuerta plans to use Manzon as a scapegoat for having a sidearm on her during the botched sting operation, but Debra fiercely defends her by asking LaGuerta to "stick together" rather than pinning the blame on someone else. However, Manzon backs LaGuerta's version of the story, blaming the incident on Debra alone and thus betraying Debra's trust. Manzon is rewarded with a sudden promotion to detective and transfer to the detectives division – leaving Debra, the enraged scapegoat, working in the dreary file room.
Jordan Chase 
Jordan Chase (birth name Eugene Greer), is a highly intelligent and well known and highly regarded author, a motivational speaker, and the main antagonist of Season 5. His book Take It Now is an international bestseller, and Vince Masuka counts himself among Chase's most loyal fans. Alongside his books, Chase is also famous for his audiotapes and seminars, encouraging people to "take what they think they deserve". In private, Chase is actually a misogynist, misanthropic, cynical person who uses his words to encourage people to act out their frustrations. He was obese as a teenager, a fact which caused Dexter and Lumen to misidentify him in a picture of the 'Barrel Girl' gang as teenagers.
When Dexter and Lumen start tracking down the members of a secret circle of men responsible for the rape, torture and murder of several young women, they come to suspect that Chase is a part of it. They are eventually proven right, and that he is the driving force within the circle. Even though Chase never participated in any actual rape or killing, he cheered on and commanded his followers, watching and videotaping them as they brutally raped and tortured their victims, delighting in mocking and tormenting Lumen and the other victims.
Dexter approaches Chase, claiming to seek counseling for his grief over Rita's death, Chase eventually figures Dexter out. He responds by sending a message, through Lumen, that not only does he know about Dexter's motive for having contacted him, but he is also aware of Lumen's identity as the circle's escaped victim. With this, he enters the police station giving his DNA voluntarily (as he never touched them, only commanding and cheering the others on), and begins planning to destroy Dexter. He allows Emily Birch to identify the last attacker, Alex Tilden, knowing that Dexter and Lumen would execute him, planning to set them up to the police. However, they escape as they moved Alex to another house before killing him, with the police finding the house empty.
In another attempt to catch Dexter and Lumen, Chase has Emily call Lumen to convince her and Dexter to come to her house, planning to kill all three of them to cover all his tracks. However, only Lumen shows up, which sends Jordan into a rage. While he is screaming at Lumen, Emily tries to defend her, and Chase kills her with a fireplace poker. There is an off-screen scuffle between Lumen and Jordan in which he stuffs her into the trunk of his car. He then drives her to an abandoned summer camp he owns outside of town (under the name Eugene Greer, presumably to avoid suspicion), which is the location each of the gang's victims (including Lumen) had been raped and tortured. Dexter eventually arrives, and is subdued by Chase. He takes Dexter into the basement where Lumen is, and inspects Dexter's kill tools. He notices one knife is missing, which Dexter hid and uses to stab Jordan in the foot and subdue him. As Chase is restrained, he mocks Dexter's belief that killing him will atone for failing Rita. He also takes credit for the new strength in Lumen, claiming that he allowed her to discover it. He then taunts her by reminding her of the pain she suffered the last time she was in the room, and an enraged Lumen stabs him in the heart. As he is dying, she tells him "that's not just for me, that's for everyone you've hurt, even Emily".
Sonya becomes Harrison's nanny after Rita's death. For most of the episodes, she mainly takes care of the infant and offers her opinion of his development. She appears a warm and gentle woman, originating from Ireland, and a devoted Catholic. A former hospital nurse, Sonya explains that she was let go due to budget cuts, and therefore is more than happy to become Harrison's nanny. After some initial arguing over Dexter's parenting and tendency to, from Sonya's point-of-view, put his work before his son, she decides to quit working for him. Much thanks to Sonya's love for Harrison, Dexter is able to convince her to come back. She does not appear in later seasons; Dexter has since hired Angel's sister as his nanny.
Stan Liddy 
Stan Liddy was a corrupt narcotics cop, under investigation by Internals Affairs detective Jim McCord, with help from LaGuerta. Quinn hires Liddy to look into Dexter's past. Liddy discovers Lumen and takes pictures of Dexter and Lumen disposing of Cole Harmon's body, though he is not sure what was in the bags. Liddy, assuming the bags to contain either drugs or a dead body, attempts to report to Quinn, but Quinn ends the investigation as his feelings for Debra now have become serious. Liddy refuses to stop, believing he has stumbled upon criminal activity that he can use to reintegrate himself in the police force. After Dexter realizes he's being watched, Liddy successfully sets a trap in his van and manages to apprehend Dexter. Having phoned Quinn, ordering him to come to the van's location, Liddy attempts to force a confession out of Dexter in order to regain his (Liddy's) reputation and status as a police officer. However, Dexter manages to fight back and in a short struggle, kills Liddy with his own knife in self-defense. When Quinn arrives at the van, he tries calling Liddy and shortly walks away, but not before a drop of Liddy's blood drops on to his shoe. Dexter then disposes of Liddy's evidence. The police find Liddy's body, and Quinn is considered a suspect, due to Liddy frequently calling him and the blood on his shoe. Quinn refuses to say what the nature of their relationship was, likely to protect Debra. Realizing how much Quinn means to Debra, Dexter sabotages the blood test, making it appear that it was not Liddy's blood on Quinn's shoe, clearing him. Quinn later thanks Dexter for this, although Dexter pretends to not know what Quinn is talking about.
Additional characters, introduced in season 6 
Brother Sam 
- Mos Def (credited as Mos & yasiin bey)
Brother Sam is a reformed criminal who runs an auto-body shop in Miami where he tries to extend his good luck to other ex-convicts by giving them a place to work. While Dexter is skeptical of his reformation, Brother Sam proves himself redeemed and Dexter befriends him, introducing him to Harrison.
At the end of the fifth episode, Brother Sam was shot in his garage by Nick, an ex-gang member who wished to return to the gang. On his deathbed, Sam tells an angry Dexter to forgive Nick for the shooting as he has done.
James Gellar 
Professor James Gellar is a former religious studies teacher at the University of Tallahassee, fired for stealing an ancient Roman sword which belonged to John the Revelator. Gellar had since then gone underground and was unheard of until the Doomsday Killings. Gellar has a blog, which has a cult following; it is dedicated to explaining the End Time as described in the Book of Revelations. With time, Gellar became consumed in recreating these scenes with his apprentice, Travis Marshall, acting as the two witnesses. The first three killings are successful, but Gellar's callous treatment of his victims leads to Travis releasing their Whore and leaving him. Gellar continues to stalk Travis and his sister Lisa, and upon seeing her talk to Deb, he kills her in the playground as the Whore of Babylon, kidnapping Travis when he arrives. Chaining him in the headquarters, he berates him before branding him with an iron. Upon Dexter's arrival, Gellar is able to escape while observing Dexter.
Working alone, Gellar tracks down the devoutly atheist Professor Casey, whom he sees as a false prophet and disembowels to serve as the seven bowls; he uses Casey's hand to paint a message for Travis in blood. Travis tells Dexter that he posted on his blog telling him to meet, where an angry Gellar tells Travis to repent, before knocking him unconscious. As Dexter searches the church for clues, he discovers an opening that leads to a basement. In that basement, Dexter is shocked upon seeing Gellar's dead body in a freezer, concluding that Travis was acting alone the entire time, under Gellar's imaginary guidance. In reality, Travis was the one who stole the sword three years prior to the doomsday killings, incriminated Gellar and came up with the gruesome idea to act out the End of Days. Gellar called Travis on his delusions and advised him to seek professional help, but instead, Travis stabbed Gellar multiple times to "prove" their immortality. Refusing to grasp reality, Travis stored Gellar's body in the freezer, keeping him alive in his delusions, until Dexter's discovery forced Travis to accept Gellar's death and move on to find new disciples.
Jamie Batista 
Jamie Batista is Angel Batista's sister. Dexter hired her as Harrison's nanny, while she studies for university. Her tendency to be in scantily-clad clothing in public leads to some issues with her brother, due to their age difference.
She has begun to build a relationship with Masuka's third intern Louis, a game developer. While Jamie attempts to get Batista to accept him, he attempts to scare him away when she is away at dinner. After Dexter mails Louis' secret video of Louis with a prostitute to Jamie, Jamie breaks up with Louis.
Mike Anderson 
Mike Anderson is the new detective hired in lieu of Deb's promotion to Lieutenant. Transferring in from Chicago, he initially causes friction by believing Debra is only pranking him when she introduces herself as Lieutenant, which Debra dismisses to maintain her composure. He however begins to mesh well with the team, noting on Dexter's incredible deductive skill in bloodwork and leading the religious research division of the Doomsday Killings when he notes the religious significance of the "tableaux" as he dubs them.
He is murdered in the first episode of Season 7 by Viktor Baskov.
Ryan Chambers 
Ryan Chambers is a forensic intern and newcomer to the Forensics department in Miami Metro Homicide in Season 6. She attends the university Vince Masuka teaches a class for in Forensic studies. Originally a fellow student, Peter, was chosen in favor for an internship with Vince, as he placed the highest test scores. However, later on when Omar Rivera's body was found, Peter faints at the scene, and Vince immediately replaced him with Ryan. She works alongside Vince Masuka during the Doomsday Killings acting as both his partner in the case and understudy, and slowly forms a relationship with him. Vince worked up the courage to ask her out on a date, and Ryan agreed.
Ryan has a fascination with the buried Ice Truck Killer case; Masuka eventually brought up the evidence from the investigation for her to look through as a sort of gift. She expressed her fascination with the case, having followed it since the details were made public. A mannequin arm left in the evidence box was later stolen by her and sold on the internet because she needs money for rent. The breach of trust led to Vince replacing her with Louis Green, leaving Vince quite sore about it.
Travis Marshall 
Travis Marshall is a researcher in artifacts, professionally a bible restorer who is tied to the Doomsday Killings (DDK, also stands for 'Doomsday Killer') and the main antagonist of Season 6. He is in fact directly involved in these murders, with mentor Professor James Gellar passing on his legacy to his student, making him believe that every murder committed is justified. However, his empathic nature leads to him to come in conflict with Gellar's demands. Travis has a sister Lisa (Molly Parker), a teacher, who tells her students that he is a talented artist.
As the season progresses, particularly after his encounter with Dexter, Travis begins to feel guilty about the suffering of their victims despite Gellar's insistence that the victims are sinners and their deaths are necessary. When told to brand their "Whore of Babylon" he relents to her suffering and releases her, which leads to the police looking for an accomplice. He also leaves Gellar and returns to live with his sister, though Gellar continues to stalk him. When the police department begin researching possible accomplices, his sister answers Debra's house call. Dexter also attempts to recruit Travis before the police find him, which Travis refuses in fear of Gellar. Deciding he has waited long enough, Gellar brands Lisa as the Whore and kidnaps Travis, chaining him at their base. Dexter tracks down their headquarters, but Gellar escapes. Travis pledges allegiance to Dexter in vengeance.
Dexter stashes away Travis while he hunts for Gellar; Gellar somehow finds him and paints a message to repent on the bathroom wall, which Travis tells Dexter is a message to meet. On arrival, Gellar reprimands Travis and allows him to return, though he knocks him unconscious. When Dexter enters, he attempts to locate Gellar but instead finds Gellar's frozen long-dead body. Dexter concludes that Travis has a dissociated identity in Gellar.
When faced with the body of Gellar, Travis detaches himself from his persona of Gellar and resolves to "finish what they started", seeking new acolytes in the Dorseys to complete the tableau of "Wormwood", a poison gas attack. He also is determined to locate Holly Benson, the first Whore, and kills her. While hiding out with Beth Dorsey, Travis detains a lone Sergeant Batista, and sends Beth with Wormwood to attack Miami Metro, which Dexter narrowly averts.
While falling for a trap Dexter sets, the side-effects of the gas's components disorients Dexter which allows Travis to defeat him, completing his "Lake of Fire" tableau in the middle of the ocean.
In the season finale, Travis, believing Dexter to be dead, prepares for his final ascension into Heaven by completing the last of his tableaus during a solar eclipse. Hiding in Dexter's empty apartment, Travis learns of Harrison, and as the final sacrifice requires the death of an innocent, Travis kidnaps Harrison at his Catholic school's Sunday pageant and attempts to kill him atop the Miami Transcorp Building. In the midst of his ritual, Travis is halted by the reappearance of Dexter who proceeds to bargain his life for Harrison's. As Travis believes Dexter to be the embodiment of The Beast and values his death above all others, he agrees to release Harrison but not before demanding that Dexter inject himself with some of his tranquilizers to render himself unconscious. Unbeknownst to Travis, Dexter, having anticipated his demands, plays possum manages to overpower DDK, knocking him out during their ensuing struggle. After dropping Harrison back home, Dexter brings Travis back to the abandoned church, and after a heated debate concerning the existence of God, Travis screams that it is not God's Will that he is to die by Dexter's hand, with Dexter concluding that things are exactly the way they are supposed to be. Dexter then stabs DDK in full view of his sister Debra, who had unknowing walked into the church at the exact moment Dexter murdered Travis.
At the beginning of Season 7, Debra and Dexter burn Travis' body to make it look like a suicide. By the end of season 7, Capt. LaGuerta uses the circumstances of Travis Marshall's death to conclude that Dexter is the Bay harbor Butcher.
Louis Greene 
Louis Greene is the third intern in Miami Metro PD's forensics department, replacing Ryan. He is a computer genius, whose expertise leads to critical breaks in the Doomsday Killer case. Louis falls for Detective Batista's sister, Jamie and reveals he is well off due to his side-gig of developing video games. Louis was developing a video game based on serial killers, and seeking Dexter's approval, showed him the game much to Dexter's disgust. He seems to have a hunch on who Dexter is, as he sends the Ice Truck Killer's hand to Dexter's home. He tries to destroy Dexter for discouraging his video game for which Dexter warns him to leave his life, to which Louis refuses. Dexter gets him fired and broken up with, leading Louis to attempt to sabotage Dexter's boat. In the process, he ends up getting killed in a mix up with people trying to find Dexter.
Additional characters, introduced in season 7 
Viktor Baskov 
Viktor Baskov was a member of the Koshka Brotherhood and the head of their operations in America. While in Miami, he killed Detective Mike Anderson after Anderson discovers a dead stripper in Baskov's trunk. He attempts to flee the country afterwords, but is intercepted at Miami Airport by Dexter. He is Dexter's first kill in Season 7.
George Novikov 
George Novikov is the manager of a strip joint, The Fox Hole, owned by the Koshka Brotherhood. Novikov puts pressure on a reluctant Quinn to destroy evidence against Isaak Sirko in a murder case by threatening Nadia's safety. He later informs the Brotherhood of Sirko's erratic behaviour and continues to blackmail Quinn so his drugs shipment won't be intercepted by police. After the two assassins the brotherhood sent failed to get Sirko, George shoots him himself. He is killed by Quinn in the episode The Dark... Whatever after he physically assaults Nadia twice. Quinn has Nadia help him out by shooting him in the arm while the gun is in George's hand, so that the murder can be set up as self-defense, although Quinn's partner Batista quickly sees through the ruse.
Isaak Sirko 
Isaak Sirko is a high-ranking member of the Koshka Brotherhood, a Ukrainian based international crime syndicate with operations in Miami, and a main antagonist of Season 7. After the disappearance of Viktor Baskov, one of Isaak's top subordinates, Isaak travels from his home in Kiev, accompanied by his bodyguard and right-hand man, Jurg Yeliashkevych, to Miami, in order to investigate Viktor's vanishing. Cunning and ruthless, Isaak begins tracking down Viktor, and upon realizing that Viktor was killed, he sets out to avenge him. His trail leads him to Dexter's boat, the Slice of Life, which Louis Greene was trying to sabotage. Louis tells Isaak that the boat belongs to Dexter Morgan, at which point Isaak promptly shoots Louis in the head. Isaak later shows up at Dexter's apartment, with an arsenal of killing tools, prepared to murder him. However, Dexter manages to lure Isaak away from the apartment to a restaurant, where the two (by phone conversation) speak to each other for the first time and Isaak reveals his intentions to kill Dexter. As Isaak continues to hunt down Dexter, who is forced to flee from his apartment and no longer able to use his own car, Isaak learns of Dexter's vigilante serial killer persona. In an attempt to kill him, Dexter leads Isaak, who was at the time following Dexter, into a bar owned by the Koshka Brotherhood's Colombian rivals, the Rojas Cartel. Three armed Colombians attack Isaak, but Isaak disposes of them all in rapid succession. This leads to Isaak being brought in by Miami Metro and later incarcerated. Dexter visits Isaak in prison, where Isaak reveals that he is not nearly finished with Dexter yet.
Isaak is later released from prison after Joey Quinn, who is being blackmailed by George Novikov, disposes of the DNA evidence linking Sirko to the murder of the three men. Much to George's affliction, Isaak continues to pursue Dexter, a campaign which begins to get in the way of the brotherhood's more profitable operations. With approval from the leaders of the Koshka Brotherhood in Kiev, George sends a hitman to dispose of Isaak. Fortunately for Isaak, the hitman is disposed of by Dexter. Now aware that he is no longer welcome in the Koshka Brotherhood, Isaak begins operating alone (with Jurg as his sole aide), with his only purpose left in life being to kill Dexter. In a public bar, Isaak and Dexter meet once again, where Isaak expresses that "Under different circumstances, I'm sure we could have been good friends." There, Isaak also reveals that he was in a romantic relationship with Viktor and that Viktor was the only person he could express himself to. Following this, two of the Koshka Brotherhood's top hitmen, Oleg Mickic and Benjamin Caffrey are sent to Miami to kill Isaak. Isaak, unable to confront the hitmen himself, decides to enlist Dexter's help in killing them, ensuring his cooperation by kidnapping his girlfriend, Hannah McKay (who would be left in the hands of Jurg), and calling a permanent truce between the two parties.
Dexter eliminated Mickic at a shooting range. Later, a meeting between Isaak and Dexter results in a heated discussion, which causes Isaak to believe that he himself may have been partially responsible for his lover's death. Isaak and Dexter later manage to dispose of Caffrey by having Dexter lure him on to a freighter, where Issak quickly guns down Caffrey. While Dexter disposes of Caffrey's body, Isaak is cornered by George Novikov, who shoots Isaak in the gut. George attempts to finish Isaak off, but flees at the sight of Dexter. Knowing his wound is fatal, Isaak asks Dexter to dispose of him in the same place where he disposed of Viktor's body. On the way to Isaak's final resting spot, Isaak and Dexter discuss how Dexter felt like he had no control over his life since he met Hannah. Isaak states that he felt the same way, detached from society and forced to hide a secret, until he met Viktor. With his final breath, Isaak tells Dexter that there is still hope for him.
Jurg Yeliashkevych 
Jurg Yeliashkevych was a member of the Koshka Brotherhood. He was Isaak Sirko's bodyguard. Jurg accompanied Isaak to Miami while the latter was investigating the death of Viktor Baskov. Strong and silent, Jurg is highly loyal to Isaak, remaining loyal to him even when Isaak is removed from the Koshka Brotherhood. At this time, Jurg assisted Isaak in the kidnapping of Hannah McKay, in order to assure the cooperation of Dexter Morgan in killing Oleg Mickic and Benjamin Caffrey. However, while Jurg held Hannah at the home of Andres Rodriguez, the deceased boss of the Rojas Cartel, Hannah tried to poison Jurg in an attempt to escape. Although the poison was not fatal, it allowed Hannah to bash him over the head with a lamp, but not before he stabbed her in the stomach. Although Hannah's wound was non-fatal, Jurg was killed in the struggle.
Hannah McKay 
Hanna McKay was a fifteen-year-old from Alabama when her boyfriend Wayne Randall commenced a three state killing spree. She spent six years in Juvenile detention after pleading guilty to being an accomplice. She claimed not to have actually committed any crimes and received immunity from prosecution after agreeing to testify against Randall.
She married an older man but poisoned him when he was pressuring her to have an abortion, in spite of later claiming she wanted to have the child. She inherited her gardening business from her mentor, whom she is later suspected of poisoning with aconitum.
When Randall decides to reveal where the last of his victims were buried, Miami Metro Homicide wants a DNA sample from her. Dexter is assigned to get the sample and he seems quite infatuated with her, becoming uncharacteristically distracted in his work.
After Randall commits suicide, she assists in locating the remaining bodies. After uncovering the bodies of a couple Wayne killed, Dexter realizes Hannah’s story isn’t truthful. While on a date, Dexter takes Hannah to a closed Christmas-themed amusement park, where it turns out Dexter has a kill room set up. He prepares to kill Hannah, but cannot go through with it and releases her. They end up having sex in the kill room instead.
When Sal Price, an investigative true-crime writer who has written a book about Wayne Randall, wants to write a sequel about her, she agrees to an interview. She admits to stabbing the woman at the hotel. She poisons Price who later collapses and dies in Dexter's apartment. Furious over Sal's death, and knowing that Hannah had confessed to him, Debra calls Hannah in for questioning. Debra has very little proof against Hannah and instead baits her with information about a miscarriage. Dexter realizes that Hannah is showing sincere emotion - this isn't an act. Dexter later confronts her at her home, telling her that Price's death was needless. Hannah is touched to learn of Dexter's deleting of Price's files. The two later sleep together.
Realizing that Hannah has gotten away with killing Price the next day, Debra Morgan would discover Hannah got away with killing Price and, angry that she got away again, called Dexter and asked him to kill her, surprising Dexter. He refused, trying to make it look like because there's no proof and because he can't do it, disappointing Debra. Hannah would later be visited by Debra and warns Hannah that she won't get away with this and as Hannah tries to apologize, Debra says she hasn't even begun to be sorry, worrying Hannah.
Hannah falls foul of Dexter by poisoning Debra. Hannah had tried to form a truce with Deb but she declined. She spiked Debra's drinking water causing her to pass out while driving. Dexter later gives Deb evidence to prove Hannah poisoned Price. Debra has Hannah arrested.
Dexter visits Hannah in prison. She admits she poisoned Debra because she tried to separate her from Dexter. Dexter tells her he had no choice but turn her in because he doesn't want anything happen to his sister. Hannah assures Dexter that she won't tell his secret when she got to trial. Dexter and Hannah share a passionate kiss before Hannah bites Dexter's lip as a sort of revenge for everything that has happened. Before she stands trial, she is confronted by Debra Morgan. Hannah plans to plead "not guilty" and that she will confess her crimes when Deb confesses hers. Debra tells Hannah her conscience is clean, to which Hannah replied that she is lieutenant of Miami Metro Homicide but still knows about Dexter's secret and ask her how she can bring her to justice but not her brother. During Hannah's arraignment on murder charges, Arlene slips Hannah a substance that causes a seizure. Hannah is taken to the hospital and escapes. She is last seen leaving a plant on Dexter's doorstep, becoming the first main antagonist to survive a season.
Nadia is a Ukrainian dancer at a strip club linked to the Koshka Brotherhood, and also the same establishment that employed murdered dancer Kaja Soroka. When Miami Metro focuses its investigation into Det. Mike Anderson's murder on the club, she eventually enters into a romantic relationship with Quinn. She is aware of and fears the criminal element that runs the club. By threatening Nadia's safety, George Novikov convinces a reluctant Quinn to destroy evidence against Isaak in a murder case. Nadia eventually flees Miami to get work in Las Vegas.
Minor characters 
Minor characters in season 1 
- Mike Donovan (Jim Abele) is a 42 year-old pastor and Church choir conductor who raped and killed at least 3 young boys, Corey Balanti, Tyler Kale and Joe Bigalow. He is Dexter's first victim shown in the series. Dexter chokes him inside his station wagon and forces him to drive to a house on the outskirts of Miami and forces him to look at his crimes. He then kills him with a hand saw, where Donovan had buried several of his victims (who are exhumed by Dexter and shown to Donovan shortly before his death). His wife comes to the station the next day to report his disappearance. Dexter shows particular anger towards him, which could be because of a personal hate for pedophiles or that they were still finding the character of Dexter. In Darkly Dreaming Dexter, this character is referred to as "Father Donovan", suggesting that he is a Catholic priest. There is no mention of him having a family. Unlike the television show, Father Donovan's victims include both boys and girls. Also he thanks Dexter for killing him, recognising his own 'sickness' and grateful for the relief.
- Jamie Jaworski (Ethan Smith) is a 29-year-old hotel valet with a taste for sexual sadism and snuff films. He recorded his rape and murder of Jane Saunders, mother of 2 small boys, and posted it on the Internet. He had been formerly arrested but escaped justice due to a faulty search warrant. Dexter, whilst stalking him, noticed a red devil tattoo on his arm and identified him from it in the video on the fetish website. In order to capture him Dexter lures him with a photo of his latest kill and then sticks a syringe in his neck. He kills him at a deserted construction site where Jaworski had been stealing copper pipes. He is Dexter's second victim on the show. In Darkly Dreaming Dexter, Jaworski works as a janitor who abducts young girls. Frustrated by the Tamiami Slasher case, Dexter kills him very sloppily, even forgetting to take a blood sample from him. The Slasher kills his next victim in a similarly messy way as a form of satire.
- Jane Sauders (Neeona Neel) was a mother of two boys. She was raped and killed in a snuff film by Jamie Jaworski. Her children were emotionally devastated after her death and Dexter avenged her by killing her murderer.
- Carlos Guerrero (Rudolf Martin) is a powerful drug lord responsible for the death of Officer Ricky Simmons and his wife Kara. Dexter at one point thinks about killing him but decides that he did not fit the code and that he had just chosen to live in a dangerous world. Sergeant Doakes becomes Guerrero's main target after accusing him of murder in front of his church and daughter Rose. In an act of retaliation, Guerrero has men tail Doakes in several attempts to scare him off. Guerrero eventually kidnaps him, and is ready to execute him when Guerrero is shot by several officers, including Kara's brother Detective McNamara (portrayed by Scott William Winters). It becomes clear that Doakes' colleagues had used him as bait to get to Guerrero—thus getting the evidence they needed to finally having the drug lord convicted.
- Norberto Cervantes (Cristos) was a professional hitman and assassin working for Carlos Guerrero. Norberto was dispatched to kill Officer Ricky Simmons when Carlos discovered that he was an undercover cop trying to infiltrate his organization, and Norberto did so by throwing him off a freeway overpass, but not before Ricky bites and takes a chunk of flesh out of Norberto's arm. Norberto then checked Ricky's phone, and discovered he had been in constant contact with his wife, Kara, and to prevent information leaking to the police, Norberto went to the Simmons residence, and shot Kara in the back and departed, but not before his bleeding arm left a drop of blood at the scene. When Kara succumbed to her injuries in hospital, her secret lover, Doakes, was driven to investigate harder and soon discovered the DNA trail and arrested Norberto. LaGuerta offered Norberto a more lenient sentence in exchange for providing enough evidence to bring down Guerrero, and he seriously considered this, but somehow Guerrero knew, and arranged for another one of his assassins, disguised as a prison guard, to bring Norberto to the prison's showers, where he stabs Norberto to death.
- Kara Simmons (Maureen Moldoon) was the wife of Ricky Simmons. She became evidently unhappy with her relationship with Ricky and became unfaithful to him by sleeping with the sergeant James Doakes. After her husband was shot for working undercover, Carlos Guerrero sent a man, Norberto Cervantes, to their house and shot her in the stomach, she tried to call her husband during the attack. Soon after, María LaGuerta and James Doakes arrive on the scene to find her gutshot. James Doakes becomes very concerned with her recovery and stays by her side while she is in hospital, to the suspicion of LaGuerta, who later confronts him with her theory that he is sleeping with her, to which he admits that he was. Doakes is shown to be very upset and vengeful regarding Kara's death.
- Matt Chambers (Sam Trammell), also known as Matt Brewster and Matt Rasmussen, is a 35-year-old alcoholic. Dexter first learns of him in court by noticing the crying family of his latest victim, Alexander Pryce (18). Chambers uses his AA sponsor to vouch for his false recovery and he is found not guilty due to a mask of emotions that instill empathy and sympathy from people, where only Dexter could see his emotions were completely fake. Matt is a repeat drunk driver, who has killed and crippled several people, yet shows no remorse or guilt for his crimes, the people he has killed and severely injured while driving drunk, and the horrible way his actions effected all those who loved his victims. Whenever he kills or injures someone in a drunk driving, he changes his name and moves to a new city. Dexter kills him in an abandoned liquor store.
- Sean (Richard Gunn) is a mechanic and temporary boyfriend of Debra's. Dexter and Rita double dated with them and Debra got on well with him, but later he turned out to be married and after Debra found out that he was using her as a bit on the side, she dumped him. He plays a part in making Dexter's relationship with Rita uncomfortable as she notes that they get on well with each other and that she and Dexter do not have the same fluency in their relationship.
- Shanda (Lizette Carrión) became friends with Debra during Deb's undercover work as a prostitute. Shanda, being street prostitute herself, became a helpful resource in the Miami Metro PD's hunt for the Ice Truck Killer.
- Jeremy Downs (Mark L. Young) is a 19-year-old boy living in a halfway house after he is released from juvenile hall. At the age of fifteen, he was convicted for killing another boy. Dexter attempts to kill him, but lets him go after finding out that his victim raped him. Before leaving he encourages Jeremy to only kill those who deserve to die. After Jeremy killed a second innocent boy Doakes arrests Jeremy. While he is detained, Dexter talks to Jeremy who revealed to Dexter that the trauma from the rape has left him just like Dexter, "empty", and he kills to feel something—although he does admit that it does not help, and in fact makes the feeling worse. Dexter later visits Jeremy in prison, as he is the only one who can understand him, and vice versa, but finds Jeremy had killed himself.
- Nurse Mary (Denise Crosby) is Dexter's first victim, as seen in flashback. She was nurse who over-medicates her patients with morphine who will eventually die from overdose. Dexter incapacitates her with a syringe which is where he obtained his syringe technique. She believes that she is helping her victims by "ending their pain", and keeps an album containing their obituaries. Harry Morgan almost becomes one of her victims when he has a heart attack and is placed in her care. Harry gives Dexter 'permission' to kill her and he ambushes her at her house. Her victims were Phoebe Burns, Jason Kheel, David Nammers among others. Dexter gives her the nickname "First Nurse" in the series, although in the novels her nickname is "Last Nurse". In the novels, the nurse is basically the same as in the TV series. However, her motivation for killing her patients is never given in the novels. In the TV series, she claims to be helping her victims by "ending their pain". She is speculated to have been inspired by prolific serial killer Harold Shipman.
- Tony Tucci (Brad William Henke) is a security guard in an ice skating rink. LaGuerta initially thinks that Tucci is the Ice Truck Killer, and puts out an arrest warrant for his arrest—one quickly rescinded when the real killer kidnaps him. The killer amputates Tucci's left arm and right leg- Dexter realising that Tucci is still alive based on the blood flow in the severed limbs being unaltered- and leaves them as clues for Dexter to find, choosing locations that Dexter visited with Harry based on photographs in an album of Dexter's. The killer eventually leaves Tucci in an abandoned hospital for Dexter to find, as a sort of invitation to kill him. He fails to meet Dexter's code, however, and Dexter sends Debra an anonymous tip leading her to the hospital and Tucci. Because of LaGuerta's rash decision to brand him as the Ice Truck Killer, this (along with a few other rash decisions) led her to be demoted.
- Mrs. Tucci (Gina Hecht) is Tony Tucci's mother. She was inconvenienced by Lieutenant María LaGuerta's false accusation of her son, followed by his kidnap and María was forced to apologize to her by Captain Matthews, but she was thankful rather than displeased that she came in person. Throughout the time her son was kidnapped, she prayed almost non-stop and towards the end of the episode reminded María of her faith.
- Nina Batista (Angela Alvarado Rosa) is Angel's ex-wife. The couple separated some months prior to the series premiere, following Angel having an affair with another woman. Despite Angel's attempts to get Nina back, she constantly turn him down. However, as seen following Angel nearly fatal confrontation with the Ice Truck Killer, Nina still cared a lot for her former spouse. Even so, neither Nina, nor the couples daughter Ally, has been seen or referred to following the end of the first season.
- Neil Perry (Sam Witwer) is a brilliant, but deeply disturbed, computer analyst with a compulsion to kill animals. Neil was regularly abused by his mother, but never struck back; only when she died of a heart attack did he finally lash out, mutilate her corpse and bury it outside his trailer home. Neil began to see the chance for fame during the Ice Truck Killer case, using his own skills to hack into the police database and reading the newspapers. Eventually, he set himself up as the killer, kidnapping a prostitute in a fake attempt to kill her, possessing photographs of the corpses not released to the public, allowing his mother's corpse to be discovered, and readily confessing to the murders. While in prison awaiting trial, Dexter, who had been contacted by the true Ice Truck Killer earlier, realized Neil was a fraud when Neil failed to recognize him. Despite Dexter and LaGuerta's insistence, Captain Matthews refused to acknowledge the possibility that they may have the wrong man, and publicly announces Neil's identity as the Ice Truck Killer. Dexter's subtle manipulation eventually drives LaGuerta into investigating Neil's innocence, and she soon realizes that he found the information in the database, though the Captain and District Attorney continue to refuse to release him. LaGuerta appears to deliberately fail to convince the Captain of Perry's innocence as a scheme to undermine him. Later on, the Ice Truck Killer pours the collected blood of several of his victims in a hotel room. Shortly after its discovery, the blood is matched to the drained victims by DNA, proving Neil's innocence to the police and leading to his release. After LaGuerta undermined the Captain by publicly stating Neil's innocence behind his back was the final straw that caused her to be demoted.
- Jorge and Valerie Castillo (José Zúñiga and Valerie Dillman) are a husband-and-wife team of human traffickers—known as "the Coyote", as only one of them was officially known about—who transport illegal immigrants from Cuba. If an immigrant cannot pay them, he or she is locked up in Jorge's junkyard, taken out on Jorge's boat and drowned. Dexter kills them both, but not before getting relationship advice out of them. Shortly after Dexter dumps their bodies, the Ice Truck Killer dives into the ocean and places Valerie's corpse (which Dexter did not have time to dismember) in the junkyard, where it is discovered by the police, almost leading to Dexter's capture until he manages to find a way to cast doubt on the evidence.
- Oscar (Cesar Flores) is a Cuban child immigrant who is found locked in the trunk of a car by Jorge and Valerie Castillo. He witnesses Dexter injecting his captors and taking them away from the keyhole in the car. After this, he develops attachment issues, trusting only María LaGuerta, who in turn develops maternal feelings for him. When asked to describe the killer by a sketch artist for a facial composite, he describes a man with facial features similar to Jesus Christ, thus saving Dexter from being caught. He is then put in his uncle's care.
- Cindy Landon (Julie Dolan) is a black widow who appears in a flashback. Her only line is "I'll fuck you if you let me go." She was the focus of an episode of Dexter: Early Cuts. She was a freelance magician’s assistant who married men and killed them for their money.
- Gene Marshall (Benton Jennings) is an arsonist, who ironically was a fire inspector, who appears in a flashback. Dexter places candles around him before cutting him up. His only line is "Have you ever watched someone burn alive?". Marshall was a real-estate developer and millionaire who set one of his own apartment complexes on fire, killing seven people. His psychiatrist deemed him mentally unfit to stand trial. After three months in a psychiatric institution, Marshall was released and went back to his usual life of luxury. Dexter killed Marshall in June 1993. Dexter surrounds him with candles when he straps him to the table.
- Alex Timmons (Demetrius Grosse) is a sniper who appears in a flashback. His only line is "Yes, I did it. Is that what you want to hear?" His death appeared in the animated webisode series "Dexter: Early Cuts" where it was shown that he was the first of Dexter's kills from which a blood-slide trophy was taken. Timmons had been a hunter since he was young, developing a fondness for killing. He later became a U.S. Marine Corps sniper, allowing him to kill in the open while masking it as warfighting. Eventually, his impulse to kill overcame him and he shot and killed three civilian children and received little punishment for it, only being discharged from the Corps. Dexter first approached him at a gun range which Timmons often practiced at. He then pretended that his car had broken down and asked Timmons for assistance. While he was distracted, Dexter sedated him, abducted him and killed him in his home with a Marine Corps combat knife. Before his death Alex admitted that he had committed the crimes which brought him there.
- Emmett Meridian (Tony Goldwyn) is a psychotherapist who, as Dexter figures out, targets financially successful women and has encouraged at least three of his female clients to commit suicide. Dexter stalks him by taking therapy sessions under the guise of Sean Ellis and to Dexter's surprise ends up making a psychological breakthrough with him. Emmett puts Dexter into a state of calm and helps him to remember his dark past, seeing a boy in blood but initially not understanding the meaning. This also helps him to let his guard down and helps his relationship with Rita. Dexter also manages a major catharsis by telling Meridian about his murders before killing him. He sees a camera recording in his office and breaks in at night to find the files on Meridian's computer showing him talking women into suicide. His victims were Meghan Dowd, Carolyn Jillian and Vanessa Gayle.
- Bob Hicks (Scott Atkinson) was Paul Bennetts' sponsor from Narcotics Anonymous for his recovery from drug abuse. Bob came around Rita's house to plead that Paul was innocent and that there had been a mistake and was there to tell him that Paul had been clean for over a month and that it was unlikely that he committed the crime. Rita politely but firmly tells him to mind his own business and he is not seen again.
Minor characters in season 2 
- Little Chino (Matthew Willig) is an enormous, powerful and dangerous, yet surprisingly cunning and intelligent, member of the Twenty-Ninth Street Kings gang, serving as an enforcer. Chino, despite his nickname, is extremely tall and well-built (his mugshot photo indicates he is just short of 6 foot 9 inches) and used a machete to kill any witnesses of his gang's crimes; and for every kill he makes, he has a teardrop of blood tattooed on his arm. Dexter targeted Chino for death after he personally killed a man and arranged the death of the man's mother (the only witness), thus leaving the woman's daughter psychologically scarred—just like Dexter. While still reeling from the death of his brother, Dexter finally pulled it together after his initial failure to kill Chino, and later after a failed ambush by Chino. When the gang was betrayed and arrested, Chino escaped to hunt down the young boy who sold out his gang, but Dexter intercepted and captured him. Dexter later killed Chino, making him the first victim of Season 2.
- Jimmy Sensio (Glenn Plummer) is a blind Voodoo high priest nicknamed "the man with God in his mouth". He can be hired to perform "death curses" by selling his targets drinks poisoned with ricin. He appears to be truly insane, claiming to be possessed by a spirit and cursing Dexter. After weeks of being stalked by Doakes, Dexter's murderous urges have become unbearable. However, he is for some reason reluctant to kill Jimmy and lets him go. Jimmy quickly leaves town, alive and well.
- Roger Hicks (Don McManus) is a car salesman who targets and murders brunette women. He uses credit checks to obtain information on his victims, ensuring that they are single, have no pets, and live in a place that keeps neighbors at a distance. When researching Hicks for his next kill, Dexter ends up buying a new minivan from Hicks. This ends up working to Dexter's advantage when he realizes it is an ideal vehicle to aid him in his killings. Dexter manages to match Hicks' DNA with semen found at a crime scene. When Dexter tells him about his relationship problems with Rita, he seems to empathize and rants on his hatred of women. An enraged Dexter quickly stabs him in his chest after Hicks uses a nasty slur to refer to Rita. Dexter also compliments Hicks on his talent for lying as he is able to change his story on a whim.
- Curtis Barnes (John Marshall Jones) is a former U.S. Army Ranger who served several tours of duty in the Gulf War. Curtis experienced, did, and saw many terrible things during his time in the armed forces, leaving him emotionally scarred. Settling down in Miami with his Vietnamese wife Alicia, Barnes' problems never leave him; he repeatedly wakes up screaming and punches holes in the walls of his home. Alicia repeatedly tells him to get help, and arranges for him to see a psychiatrist, but Barnes never goes, believing no one could help him. Alicia eventually could not take it anymore and declared to Barnes she was leaving him. In response, Barnes shoots Alicia twice through the heart, and once again through the head, all with his arm remaining steady and in the space of a split-second. Barnes flees for his life, and the police begin hunting him for his wife's murder. Somehow, Barnes learns that James Doakes, who also served as an Army Ranger, is leading the investigation, and arranges with his friends in the military to lead Doakes to him on his boat. Doakes goes with no support, as he was informed the man he was meeting was a member of Barnes' unit, rather than Barnes himself. Doakes sympathizes with Barnes, as he shares his emotional problems, and Barnes tries to convince Doakes to stall the investigation long enough for him to arrange passage to Cuba. Doakes, however, tells Barnes that turning himself in is a better way to deal with his pain. Barnes refuses to surrender, and raises his gun, forcing Doakes to kill him.
- Santos Jimenez (Tony Amendola) One of the three men present at the murder of Dexter's mother, Laura Moser. Jimenez was able to cut a deal with police and he was included in the witness protection program. In his old age he was running a tavern in Naples, Florida, while at the same time he continued to sell cocaine. Dexter tracks him down and finds that he is a bartender, he waits for him and beats him and attempts to kill him but in a moment of confusion, Lila is able to convince him to stop. Later, in an attempt to bring Dexter and her back together, Lila gives Jimenez the address of the bowling alley Dexter will be leaving. Waiting outside his truck, Jimenez slashes Dexter's arm with a knife and escapes. After Lila's influence nearly gets him exposed as a killer, Dexter abandons what she taught him and kills Jimenez with a chainsaw, the same weapon used to kill Laura Moser. Afterwards, Dexter had to leave his body at the cabin because he had to go to Rita since Lila had broken into her home. Dexter went to Jimenez's cabin at night and attempted to dispose of his body. Later, Jose Garza came looking for Jimenez, because he wanted to get his cocaine, but was caught by Dexter. Since Santos killed Laura Moser, he was responsible for Dexter turning into a serial killer despite that Dexter only kills dangerous criminals who commit murder.
- Ken Olson (Silas Weir Mitchell) is a wannabe vigilante inspired by the Bay Harbor Butcher. He has successfully killed two criminals. One was a drug dealer he ran down with his car (Olson stole his drugs afterward). The other was an abusive husband whose anger was provoked when Olson slept with his wife, who was pushed down a flight of stairs. His third attempted victim, a robber who hurt Olson's mother, escaped by stretching out the rope Olson used. Dexter originally planned to stop Olson without killing him. Upon learning of Olson's first two victims, who Dexter believes did not deserve to die, Dexter decides that Olson must be killed. Dexter did not obtain a blood sample from Olson. Under Lila's influence, Dexter said he "had" to kill Olson (out of necessity) but did not "need" (feel the urge) to kill him.
- Juan Rinez is a pimp who murdered one of his prostitutes; he was Dexter's second human victim. He is arrested, but let off due to a faulty warrant. When Tom Matthews visits Harry Morgan during Debra's birthday party to inform him of Rinez's release, Harry loses his temper and later tells Dexter that he was right in training him. However, Dexter finds and kills Rinez himself; Harry finds his son standing over Rinez's dismembered body. Dexter later learns that Harry committed suicide days later, rather than dying of natural causes as he had previously believed, and guesses that he was unable to face the reality of what he trained his son to do.
- Jose Garza, or "Christopher Harlow", is a murderer and drug trafficker connected to Santos Jimenez. Initially supposed to make a deal with Jimenez for Garza to buy a quantity of cocaine, he was surprised and angered when Jimenez did not show up, and texted Jimenez's cell phone. By this point, Jimenez had been killed by Dexter, and the cell phone was in Dexter's possession. When Garza announced he knew where Jimenez's cabin was, where Dexter was holding Doakes captive, Dexter, knowing about Garza's crimes, saw a way to get rid of him: by killing him. Luring Garza into an ambush outside of Jimenez's bar, Dexter sedated and brought him back to the cabin and killed him in front of a horrified Doakes with a hand saw. Later, after the cabin is destroyed by Lila, Garza's brutally dismembered body parts are found as well as that of Doakes himself; which the task force considers conclusive evidence that Doakes was the Bay Harbor Butcher.
- Esteban and Teo Famosa (Gilbert Saldivar and Wilmer Calderon) were Cuban brothers and drug dealers who, after finding James Doakes in the Everglades, knocked him unconscious and brought him back to the cabin where Santos Jimenez had planned to sell them cocaine. Dexter, while protecting himself, also saves Doakes by killing them both, he snaps Esteban's neck and then shoots Teo in the head.
Minor characters in season 3 
- A carnival worker is the first victim of Dexter seen in Season 3. No background story was given as Dexter was telling his dentist that he "had fun at a carnival" and "won a prize". It also reveals that he has at least one-eighth of his new blood-slide box filled, showing there were many more off-screen.
- Oscar Prado (Nick Hermz) is the first victim of Dexter's that does not follow "Harry's Code". While attempting to seize "Freebo", Dexter is caught by Oscar and mistakes him for a junkie looking for drugs. Oscar attacks him and Dexter, in self-defense, grabs a bayonet from Oscar and stabs him in the chest, severing his aorta and killing him almost instantly. Dexter expresses remorse after killing him, especially after learning he worked with at-risk youth and that, for the most part, despite his drug use (which Debra discovered he bought from Freebo) and a few traffic tickets, he had not harmed anyone. He is the brother of ADA Miguel Prado, who is distraught over the loss of his brother. Because of that Dexter attended the funeral.
- Fred "Freebo" Bowman (Mike Erwin) was a drug dealer who has murdered two college girls. Dexter's initial try at killing him did not go as planned. When Dexter goes to Freebo's house, he expects to take him to a nearby house and kill him, but is instead attacked by Oscar Prado. The police believe that Freebo is the killer of Oscar Prado. Thus, Freebo becomes the prime target of policemen throughout the city. Dexter eventually finds and kills Freebo; but, at the scene of the crime, Miguel Prado finds Dexter with the killing tool. Dexter tells Prado it was self-defense, but Prado admits to Dexter he was going to kill Freebo himself. Meanwhile, the police search for Freebo is halted when people associated with him are killed.
- Teegan Campbell (Jelly Howie) was the drug-addicted girlfriend of Freebo. Dexter witnesses a falling out between Freebo and Teegan before he initially goes to kill Freebo. When Teegan is found dead with a piece of skin cut off, she is considered a Jane Doe, but Dexter recognizes her. Teegan is assumed by Debra to be a "strawberry", a rich college girl who pays for drugs with sex. This helps Dexter locate her apartment where he surprisingly finds Freebo hiding out. After killing Freebo, Dexter surreptitiously feeds clues to Debra that lead her to Teegan's identity and her link to Freebo. Debra, and initially Dexter, assumes that Freebo is Teegan's killer, though in reality she was actually killed by George Washington King, aka The Skinner.
- Wendell Owens (Marc John Jefferies) is a 15-year old boy who once served as the doorman for Freebo. Debra finds him and questions him, in the process establishing a friendly relationship with the boy. A short time later, when Owens is found to be the latest victim of the Skinner who unlike the previous victims died from the skinning process and not strangulation, Debra takes it personally. His murder leads Debra to the conclusion that the Skinner is tracking the investigation and using her leads to find Freebo.
- Javier Garza (Ray Santiago) is a pimp who Debra pressures information out of about Freebo. Javier is soon found dead with his skin peeled off, and it is assumed that Freebo killed him. However, Dexter killed Freebo before Javier died, and the police eventually figure out that Freebo is not likely to have killed Javier or Teegan. It was later revealed Javier was killed by The Skinner.
- Mario Estorga (Jerry Zatarain) was a tree trimmer and illegal immigrant. He had a family but would rather get deported than divulge any information on The Skinner. But when Debra puts trimmed trees in his drive to make him think that the Skinner had come to his house, he tells them that he has a cabin under a highway.
- Nathan Marten (Jason Kaufman) is a pedophile who approaches Astor while Dexter, Rita, and the kids were shopping at a grocery store. Later, while at the beach, Dexter sees Marten taking pictures of Astor. While initially hesitant to kill Marten because he does not satisfy "The Code of Harry" (he is not a killer), Dexter strangles him after it becomes apparent that Marten will eventually try to rape Astor. Possibly because he is not a murderer, Dexter does not take (or is at least not shown taking) a blood slide sample from him.
- Ethan Turner (Larry Sullivan) married wealthy women, killed them, and took their money and assets. Ethan has killed at least two wives. Miguel Prado tried to prosecute him, but could not, supposedly due to lack of evidence. Miguel brought his frustrations about the case to Dexter's attention, who investigated as well and decided to do his friend a favor by seeking out Ethan in Bimini. Upon boarding the same cruise ship Ethan was on, he trapped Ethan in his room, killed and dismembered him, then got off the ship. Miguel's office later received a fax reporting that Ethan had been reported missing, and, having been told by the Coast Guard, Dexter was not where he said he was "fishing", knew immediately that Dexter had killed Ethan. Miguel confronted Dexter about this, and revealed he had deliberately mentioned Ethan to Dexter in the hope he would avenge Ethan's victims, who the justice system had failed. Having seized this opportunity, Miguel expressed his admiration and respect for Dexter for achieving through vigilantism what he had failed to do legally.
- Clemson Galt (Blake Gibbons) is a neo-Nazi who murdered his girlfriend for getting pregnant, as well as the family of an "Aryan defector". He was found not guilty of the killings after his associates frightened or killed all witnesses. However, he was found guilty for an unrelated armed robbery and was sentenced to 15 years in a maximum security prison. Dexter suggests Galt to Miguel Prado as a target, intending to scare Prado off by showing the difficulty and risk of such a project. To Dexter's surprise, Prado brings Galt to a Miami courthouse as an expert witness and release him. Dexter, posing as a fellow neo-Nazi, picks him up only to capture him, and kill him. Dexter says that Galt had been on his "Top Ten" list of people to kill for years, but he never got the opportunity to do it, although this could just be a lie in order to sell Miguel Prado onto the idea.
- Albert Chung pushed an old woman down the stairs and escaped prosecution with the help of Ellen Wolf. Afterwards, he breaks into a house and, being discovered by a young college student named Lisa Morton, kills her and flees. He is identified by Vince Masuka because he left bloody sock prints at the crime scene, something he had done numerous times before. Wolf tries to get his charges lessened as well as several other benefits. However, she later helps turn him in to the police. Masuka shows hatred towards him as he states that "he gives Asians a bad name", even more so when Dexter observes that Masuka and Chung look strikingly similar.
- Billy Fleeter (Jeff Chase) is an ex-football player who gave up sports for gambling. Running up serious debts, he pays them off by helping his bookie kill others who cannot pay their debts. Dexter uses Fleeter to help train Miguel Prado in his trade. He shows Miguel how to research his victims to be sure they deserve to be killed (or meet the "Code of Harry" in Dexter's case). He also reveals to Miguel how to stalk and subdue his victims, as well as how to kill them and not leave any traces behind. Fleeter is killed by Miguel Prado in an old casino storage room.
- Toby Edwards (Vincent Pagano) was a bartender who Ellen Wolf hit on when she went into his bar, he flirted back and later that day calls her several times and goes around her house. She does not answer because she has been killed by Miguel Prado. Toby is later taken in for questioning and was Lt. LaGuerta's prime suspect and she vented some of her emotions on to him, but Quinn finds an alibi for him and he tips her off on the fact that he saw an SUV at the time he was there. This leads to María suspecting Miguel of Ellen Wolf's death.
- Tammy Okama (Jane McLean) is the party organizer, hired by Dexter's co-workers to organize his bachelor party. After the party she and Masuka spend the night together. Her sense of humor resembles Masuka's, and she attends Dexter's and Rita's wedding as his date. Even so, she has not been seen or mentioned since the season three finale, where she and Masuka dance at the wedding reception.
Minor characters in season 4 
- Marty (Alexander Lewis) becomes Dexter's supplier of the drugs he needs to be able to stay alert, juggling both his work, his late night killings, and his new life as a family father.
- Benito Gomez (Gino Aquino) is a former boxer who has beaten two people to death, to the point of disfiguration. A fatigued Dexter is set to testify his forensic evidence at Gomez's trial, but he brings the wrong evidence, leading to Gomez being freed. As a result, Joey Quinn was very upset with Dexter. Dexter later catches and kills Gomez in an abandoned boxing ring. He is the first victim in Season 4. It initially appears as though Dexter crashes his car with Gomez' body parts in the trunk; but it is later revealed that Dexter stored Gomez' body parts in the boxing ring where he killed Gomez.
- Zoey Kruger (Christina Cox) is a policewoman who shot and killed her husband and daughter, and hid the crime by killing the suspect. Kruger finds out that Dexter is stalking her but is initially suspicious that his motive is to re-open her murder case. She explains how family life forced her to kill her family. Dexter realizes the similarity between them, but realizes he would rather get caught than kill his family. He also realizes (to his own surprise) that he does not want to lose his family. He then kills her.
- High school sweethearts Nikki Wald (Alicia Lagano) and Johnny Rose are a pair of robbers who target tourists and shoot those who are uncooperative. When LaGuerta and Batista approach the suspects house for questioning, the Vacation Murderers shoot at them. In the fourth episode of the season, being suspected of gunning down Detective Debra Morgan and former FBI Special Agent Frank Lundy (actually committed by Christine Hill), Sergeant Angel Batista decides to reveal to the press that one of the killers, named Johnny Rose, has syphilis and has numerous partners. Within hours, the news is spread around Miami. This revelation of information was designed to create dissension between the Vacation Murderers, thus making them easier to catch. Johnny Rose was gunned down by his female partner in crime, being shot three times in the chest. She was shortly found in the street, gun in hand, having a nervous breakdown. She was tasered by Detective Joseph Quinn, and taken into custody. Wald confessed to the vacation murders and robberies but stated she did not kill Lundy or shoot Debra.
- John Farrow (Greg Ellis) is a contemporary artist and photographer who enjoyed having his subjects slightly beaten and cut, creating violent photos that disturbed even Dexter. He was also accused of a rape years before but the charges were dropped when the victim recanted; however, the lead detective believed she was paid off. When an arm of one of his models is found in an alligator, Farrow becomes the prime suspect on her and several other murders and, despite Harry's demands that he focus on Trinity, Dexter considers him a potential victim. After suggesting he photograph Debra like his models, Dexter immediately decides to kill him. After finding blood and a fingernail of the dead model at his studio, Dexter sets out to find him at a club, only for Quinn to interfere. After camping with Cody the next night, Dexter instead heads to Farrow's house and kills him in typical style, albeit using Farrow's equipment for a much more dramatic kill room. Even while strapped down, Farrow maintains his innocence, defending his work as a contrast of beauty and violence. The next morning, to Dexter's shock, Farrow's assistant Timothy Brand (portrayed by John Griffin) is arrested for the murders on airtight evidence. This revelation left Harry greatly disappointed in Dexter and left Dexter feeling what could only be described as guilt for killing the wrong person. Farrow was innocent and is the second person Dexter has killed that did not fit the Code of Harry.
- Valerie Hodges (Mary Mara) was one of Harry Morgan's many lovers. She had a romantic relationship with Harry at the same time that he was with Doris Morgan. Debra tracks her down and asks her about Harry. She initially does not remember much but later remembers the address of one of his lovers, which turns out to be Laura Moser's old house which leads to Debra discovering Dexter's brother was the Ice Truck Killer and that he witnessed his mothers' death.
- Scott Smith (Jake Short) is a boy kidnapped from his father Nick (portrayed by Roger Ranney) by Arthur Mitchell. He was rescued by Dexter before Arthur got to kill him. Later during Debra's interview with Scott, his experience helped the police to identify Arthur as the Trinity Killer.
- Stan Beaudry (Ian Patrick Williams) is a trucker who allegedly murdered a prostitute, but was never arrested due to contamination of the chain of evidence of the alleged murder weapon by the police. Dexter sets him up to be the primary suspect for the Trinity killer as Miami PD is closing in, and then kills him in his truck. This kill was done very hastily on scant evidence, lacking even the picture of Beaudry's victim, which Dexter acknowledges. Later, the police track the movements of Beaudry from city to city on his truck routes and the Trinity killer's post cards to his daughter Christine clears him as being the Trinity Killer after finding rock solid alibis for Beaudry; he was hundreds of miles from the scene of some of the Trinity Killings at the time of the murders. They determined correctly that the DNA, murder weapon, and Lundy's files were planted, but attributed this to the real Trinity Killer (the evidence was actually planted by Dexter).
Minor characters in season 5 
- Ray Walker (Adam John Harrington) is an FBI agent investigating Rita's death and its ties to the Trinity killer. Quinn asks him where the safe-house from the Mitchell family is, to ask them some questions about Kyle Butler.
- Rankin (Brad Carter) is Dexter's first kill following Rita's death. It was not, however, a murder by Harry's code, but rather an act of rage. Dexter, roaming the Miami outskirts, meets him at a boat shed, and—as Rankin taunts Dexter's dead wife—Dexter responds by beating him to death. When done, Harry appears to his son, saying that the slaughter was the first human thing he had seen Dexter do since Rita's death. It is Dexter's third known inadvertent killing.
- The Barrel Girl Gang, a raping/killing circle folds out as the main target of Dexter for Season 5. The circle is responsible for kidnapping, raping and killing twelve women; Lumen was intended to be their thirteenth victim. Their victims were initially held captive in the campgrounds where they raped their first victim, and later in the attic of Boyd Fowler. Famous author and motivational speaker Jordan Chase is revealed to be the driving force of the circle, which consists of him and his childhood friends. All five men appear in a photo, taken by their first apparent rape victim, Emily Birch. As members of the circle begin to disappear, Debra deducts that their latest victim escaped and is exacting her vengeance, with the possible help of a man who loves her. While Debra eventually arrives to the camp, almost catching the vigilante couple (in reality, Dexter and Lumen, hidden behind an opaque plastic and therefore, unseen to her), she spares them by advising to disappear before the police arrives.
- Boyd Fowler (Shawn Hatosy) works in roadkill pick-up. Dexter first targets him as he spots blood in of the van he used to move out of his and Rita's home. Fowler serves as the circle's "finisher", i.e. the one responsible for finally killing and dumping their victims. His M.O. is to electrocute them, putting their bodies in an oil drum filled with formaldehyde, and dumping the drums in the Florida swamps. Since Boyd tranquilized Dexter in his initial attempt to kill him, Dexter kills Boyd in his home, only to realize he had been watched by the circle's last victim, Lumen, whom Boyd had yet to finish off. Boyd kept locks of hair as trophies of his victims. However as he only took them once he killed the women, there are only 12 of these. This, plus Cole having thirteen DVDs, leads Debra to conclude that a victim of the circle escaped, and is killing the members.
- Dan Mendell (Sean O'Bryan) is a dentist (and called "Dan the Dentist" by Dexter, Lumen, and Debra), and the first of circle to be tracked down by Lumen after Boyd's death. She attempts to kill him by shooting him, but only manages to wound him. Not able to handle the situation herself, she calls Dexter, who initially does not believe that Mendell is in fact one of her abusers, due to the fact she only recognized his smell. However, Dexter is proven wrong when Mendell manages to phone his friends, warning them that Lumen is alive. Dexter responds by snapping Mendell's neck. He was a married man, able to keep his wife in the dark of his activities by claiming he and his friends (whom she had never met) were going on a week long fishing trip.
- Cole Harmon (Chris Vance) is Jordan Chase's head of security, as well as a part of the circle. Lumen refers to him as "Suit and Tie", since he had a habit of folding his coat and placing it on a chair before he would rape her, as well as the only rapist to remove her blindfold, as he was sure the woman would be killed. He also tortured her, leaving scars on her back. He encounters Lumen in a hotel during the seminar and nearly kills her, before Dexter subdues him. He is eventually killed by Dexter, with Lumen as a witness. Before Dexter killed him he asked what the names of the others were, but Cole refused to say. His death does however lead to a conversation with between Chase and Dexter, in which Dexter realizes that Chase is one of the men who did this. He kept videos of the circle torturing and raping their victims as trophies.
- Alex Tilden (Scott Grimes) is a bank employee who saved a piece of jewelry from each of his victims. He is the last of the circle to be tracked down by Dexter and Lumen, identified to them by Emily Birch. In attempt to save himself, Alex states that the real blame lies with Jordan Chase, claiming that he was the one who made them assaulting the women. That Chase made him do things he never would have done, enraging Lumen who tells him that they made her do things she never would have done. He then claims that he can give them Chase, only to be rebuffed by Dexter. In a final attempt to stay alive, he offers them money, all they have to do is give him a number. Lumen coldly replies "Thirteen" a reference to her DVD number, and how all she was to them was their thirteenth victim. He is then killed by Lumen, per the code of Harry.
- Jim McCord (Raphael Sbarge) works in Internal Affairs, and investigates Angel for a possible assault on a co-worker. While the investigation is dropped, Angel starts believing that McCord and LaGuerta are having an affair, and accidentally ruins an undercover operation of theirs, believing himself to walk in on them sleeping together.
- Brothers Carlos and Marco Fuentes (Joseph Julian Soria and Jose Aguirre) become the first proper suspects in the Santa Muerte murder investigation. Debra leads a storming of the Fuentes brother's apartment complex, and finds Carlos holding a teenage boy hostage with a machete—the same kind of weapon used in the Santa Muerte killings. Carlos escape the building after slitting the boy's throat. The boy survives, but the Fuente brothers have gone off-grid. Thanks to a tip from an acquaintance of the Fuentes brother, the police is able to track them down at a local dance club. However´- the arrest fails miserably, leaving the Carlos and two additional people dead, and Marco on the run again.
- Lance Robinson (Chad Allen) is a man cruising the Internet for sexual encounters with other men, occasionally killing them as well. Hoping for it to be his first "normal" killing since Rita's death, Dexter drugs him. However, before he is able to finish Robinson off, he is interrupted by a phone call from Lumen, who has just shot Dan Mendell. While Dex is attending to Lumen and Mendell, Robinson regains consciousness and tries to escape. Dexter recaptures him, kills him, and manages to stage Robinson's and Mendell's deaths as a sexual encounter gone out of hand.
- Emily Birch (Angela Bettis) was seemingly the first victim of Jordan Chase's circle. According to her story, she was victimized while she and her assailants were still teenagers, but was let to live and is still in an abusive relationship with Chase. She was also the one to take the picture of the circle, after being raped. Controlled by Chase, she set up Lumen and Dexter for a trap. However, Chase kills her after she protests the killing of Lumen.
Minor characters in season 6 
- Nick (Germaine De Leon): one of Brother Sam's employees at the garage. Wanting to remain in the gang he was a part of prior to going to prison, he murders Brother Sam to prove which side of the law he is on. He is later confronted by Dexter, who intends to kill him against Brother Sam's wishes, and asks for forgiveness, stating he had no choice. He then realizes that the police have no evidence to tie him to the killing and subsequently gloats about how he got away with it. Dexter, initially willing to let him go, then goes ahead and kills him.
- Dr. Michelle Ross (Rya Kihlstedt): a therapist who the police department assigns to Debra after she is involved in a shooting.
- Professor Clarissa Porter (Mariana Klaveno): Professor Geller's assistant who provides Miami Metro with insight into their prime suspect in the "Doomsday Killers" case. Quin has a brief affair with her.
- Holly Benson (Lacey Beeman): a would-be victim of the "Doomsday Killers" whom Travis released because he was questioning the morality of their acts. When Travis acknowedlged that Geller was no more than a figment of his imagination and hence completely responsible for the Doomsday Killings, he tracks down Benson and killed her to clean up "a mistake".
- Beth Dorsey (Jordana Spiro): she and her husband, Adam (Kyle Davis), a fanatically religious couple, team up with Travis to kill Holly Benson. She is later dispatched to Miami Metro to release Wormwood as a poison gas. Dexter, realizing her plans, locks her in an interrogation room just as she releases the gas, making her its only victim.
Minor characters in season 7 
- Ray Speltzer (Matt Gerald), was suspected of two murders, to whom Dexter believed would most likely kill again. Dexter investigated him further noting that he had access to a mausoleum at the cemetery where he worked. Dexter found proof of Speltzer's guilt inside it. Speltzer bought a girl home to his place and killed her. Debra broke in to confront him. Dexter saves Debra from Speltzer, who escaped. Speltzer removes the evidence from the Mausoleum, but is caught by local police. During Debra's interrogation he cracks and admits that he murdered at least one of the girls. The arresting police officers failed to properly mirandize him. Speltzer's lawyer uses this technicality to set him free. Dexter entered Speltzer's Motorhome to catch Speltzer off-guard, but he unexpectedly comes in and knocks Dexter out. Dexter awakes in a maze like the previous one. He manages to fend off Speltzer and escape from the roof. Speltzer attended the burial of his last victim, which makes Debra lose control and she has to be restrained. Dexter finally catches Speltzer late at night at the cemetery and straps him to the cremation bench. He then burns him and his slides of blood in the fire.
- Sal Price (Santiago Cabrera), was investigative writer who had written a book on the life story of Wayne Randall. He thought Hannah McKay might have beem more involved in the killings than previously presumed, and wanted to write a sequel about her. To further his personal investigation into the subject, he approached the Miami Metro hoping to get access to the case files. He asks Debra for a date and later tells her about the differences in the blood reports submitted by Price's guy and Dexter. The next day, Price had spotted Dexter dropping off Hannah at her home, he confronted Dexter in the street telling him he knows Dexter fudged the blood reports. Dexter managed to convince Price not to say anything in exchange for information on Wayne Randall. Price visited Hannah at work and pressured her to give interview. He threatened to go public with her relationship with Dexter. She agreed to the interview on the condition that he keeps Dexter out of his book. Price interviewed Hannah, who admitted to stabbing the woman at the hotel. Later that night, Price went to Dexter's apartment to find out what he knows about Wayne Randall. Dexter confronts Price with his plan to frame him for murder unless he backs off, but Price collapses and dies, apparently from a heart attack.
- Oleg Mickic (Karl Herlinger) was an ex-soldier, and one of the two assassins sent by the Koshka Brotherhood to eliminate Isaak. Mickic had worked for Isaak in the past, and when Isaak discovers that Mickic is being sent to kill him to see if Mickic has any loyalty to his former boss, but Mickic's mind was already made up. Mickic was a sniper who was accustomed to killing from a distance, and had a habit of buying his rifles locally. When Isaak recruited Dexter into helping him dispose of the brotherhood's hitmen, Dexter tracked Mickic to a firing range near the airport where Mickic was testing out his rifle. While Mickic was lying on his stomach for precision, Dexter came behind him and stabbed him through the torso, covering his mouth to muffle any screams.
- Benjamin Caffrey (Sherman Augustus) was a hitman based in New York and one of the two assassins sent by the Koshka Brotherhood to eliminate Isaak. Caffrey killed all of his victims with from a close range with knives. Caffrey had worked for Isaak in the past, but had no qualms about killing his former boss. When Caffrey was unable to contact Mickic, as he had been killed by Dexter, Caffrey begins to follow Dexter, who Caffrey believed would lead him to Isaak. Caffrey begins trailing Dexter, who leads him to a cargo ship. There, Dexter and Caffrey face off, both wielding knives, but before either can make a move, Isaak appears from behind, shooting Caffrey with a silenced pistol. Dexter and Isaak then threw Caffrey's body overboard.
- Clint McKay (Jim Beaver) was Hannah McKay's father. A convicted felon and gambler, he initially makes contact with Hannah to reconcile with her about his past behaviour. Things turns nasty when Hannah refuses his request for $20,000 to open a business (actually, to pay off his gambling debts), using threats of exposing her for a past murder. He trys to extort money from Dexter as well, so Dexter kills him.
- Joseph Jensen (Mike Foy) is the Phantom Arsonist. After killing seven people in two weeks, Dexter tracks him down when he runs his fingerprints through juvenile records. He initially planned to kill the arsonist himself but, instead, he hands him over to the police department anonymously.
- Phil Bosso (Brett Rickaby) is an arson investigator, who Dexter suspected as the Phantom Arsonist. However, his selection of incindiaries turns out merely to be for Civil War reenactments.
Recurring background characters at Miami Metro PD 
Alongside the main characters and supporting characters, there are some members of the Miami Metro Police Department that appear on recurring basis through the series, but only as background characters. While the actors receive proper credit for their appearances, they do not have any influence on the storyline, and mainly operates in the background, assisting the other characters. These characters include technician Karen (portrayed by Mary Alyce Kania during the first four seasons of the show), Detective Simms (portrayed by Francisco Viana in the first and second season), Detective Ramos (portrayed by Pablo Soriano in season two and three) and Detective Weiss (portrayed by Eli Goodman during season two).
Novel characters 
Darkly Dreaming Dexter characters 
- The original Dexter novel, Darkly Dreaming Dexter, upon which the TV series' first season is based, includes the characters of Dexter, Debra (as Deborah), Rita, LaGuerta (first name Midgia), Batista, Doakes (first name Albert), Masuka (as Masuoka), Harry, Astor, Cody, Doris, Laura (although unnamed), Brian, Camilla Figg, Captain Matthews, Mike Donovan (as Father Donovan), Jamie Jaworski, and Nurse Mary (only referred to as "Last Nurse"), although some of them with different characteristics. Notably, Rita's ex-husband is referred to (although not by name), but the character himself does not appear. All other season one characters are created exclusively for the television series, and do not appear in the novels.
- Daryll Earl McHale is the most notable character exclusive to the book. He is arrested for the Tamiami Trail killings after confessing to them. Dexter finds out that McHale is a security guard at the arena, and that he is prone to getting drunk, robbing gas stations and beating his wife. The character is separated into two for the TV show, with Tony Tucci as the arena security guard and Neil Perry confessing to the killings.
Characters from subsequent novels 
The first season is largely based upon the first book (Darkly Dreaming Dexter), but for the following books and seasons the stories develop separately. Thus (with few exceptions) the characters from the subsequent novels (Dearly Devoted Dexter, Dexter in the Dark, Dexter by Design and Dexter Is Delicious) do not appear in the television series, nor do the characters introduced in seasons 2–5 appear in the books.
- Kyle Chutsky is a federal agent who appears only in the book series. He is a former Special Forces operative who worked alongside Sgt. Doakes. When a member of their old unit is found with all of his body parts removed, Doakes recognizes the work of his former comrade, Dr. Danco, and Chutsky is called in to help with the case. In the course of the investigation, Chutsky is captured by Dr. Danco. His little finger, on which he wears a distinctive ring, is amputated and mailed to Debra. Chutsky is later found missing an arm and a leg but fortunately, not much else. Dexter, after examining Chutsky's finger, pockets the ring, intending to return it to Debra. The ring is found by Rita, who mistakes it for an engagement ring. In Dexter in the Dark, Chutsky stayed with Deborah and had not been returned to work for his agency due to his handicap. In Dexter is Delicious, after believing himself of no use to Deborah after the kidnapping of her and Dexter at the hands of a cannibalist coven, Kyle leaves Deborah, and despite her efforts, she is unable to find him.
- Dr. Danco is a surgeon who mutilates people while keeping them alive. He shaves his patients, then removes everything in a body that is not essential for life (arms, legs, penis, teeth, tongue, etc.), leaving his victims unable to move or communicate, driving them insane. His procedure also involves chemicals that cause brain damage. In medical school, he learned that he could cut people open without feeling any empathy. He offered his services to the United States military as a torturer. His comrades, who included Sergeant Albert Doakes, nicknamed him "Danco" after a vegetable slicing machine. The joke was that Dr. Danco, like his namesake, made sliced "vegetables". Dexter makes a similar conclusion about his victims, before the name is revealed, calling them "yodeling potatoes". Dr. Danco likes to listen to Tito Puente while working on his victims. He also plays a warped version of hangman, with his subjects being the 'hangman' in question. During a covert operation in El Salvador, he was turned in to the enemy in exchange for several prisoners. In Dearly Devoted Dexter, Dr. Danco is released and goes to Miami, looking for revenge on his former comrades. His real name is revealed to be Martin Henker.
At the end of the novel, Dexter tracks him down, but is uncharacteristically unprepared, allowing Danco to overpower him. Just as Danco is about to mutilate Dexter, however, Deborah bursts in and shoots him dead.
- Randy MacGregor is a real estate agent who rapes and murders young boys. He takes the boys out on his boat, equipped with toys and children's movies, and, when he is finished with them, ties their bodies to anchors and drops them overboard. He keeps several photos of his victims. When confronted with these photos, he says to Dexter "I hope one of them was yours." A red cowboy boot worn by the photographer in one picture shows Dexter that MacGregor has an accomplice. He appears in Dearly Devoted Dexter.
- Steve Reiker is a pedophile who photographs the young boys that Randy McGregor rapes and murders. Dexter wishes to kill him, but cannot because Sgt. Doakes keeps following him. Dexter is finally able to kill him at the end of Dearly Devoted Dexter.
- Carl is a serial killer who murdered 11 people before being captured by Harry Morgan. After catching a teenaged Dexter trying to kill a school bully, Harry introduces him to Carl to teach him the importance of not getting caught. Carl appears in Dexter in the Dark. He also appears in Season 2 as Harry took a teenage Dexter to an execution to teach him the importance of not getting caught. After the exhilarating experience, the teenage Dexter learns the importance of not getting caught.
- The Watcher is not a single person, but a group of cultists worshiping the ancient god Moloch. They believe that the spirit of Moloch jumps from one person to another. The Watcher tails Dexter, who he refers to as "The Other", in Dexter in the Dark, believing that Dexter's Dark Passenger is a child and enemy of their god.
- IT—introduced in Dexter in the Dark—is a mythical, godlike entity which has existed since the beginning of time and has several similarities to the Dark Passenger. IT's story is explained with a somewhat Biblical tone. IT takes great pleasure in entering creatures as a "passenger" and influencing them to kill other creatures. IT works to create other murderous entities similar to ITself but soon turns against many of them, causing them to flee. IT and IT's offspring go to war, with IT being victorious. Some of IT's remaining children stay in hiding, fearing IT's power.
- Manny Borque is a conceited caterer who appears in Dexter in the Dark. He is hired for a very high price to cater Dexter and Rita's wedding. He claims to be booked two years in advance. Through a contractual loophole, Manny is able to make whatever he wants and charge whatever price he decides. He is killed by members of the Moloch cult. This makes Dexter a murder suspect as he was the last person to see Manny alive and owed him a large amount of money, giving him a motive.
- "The Old Man" is the unnamed leader of a cult that worships the ancient god Moloch. His cult is responsible for several murders in which the bodies were burned and decapitated, the heads replaced by ceramic bull heads. He wields an ornate bronze dagger with the Aramaic letters "MLK" (Moloch) etched into it. He is killed by this dagger, wielded by Cody Bennett, at the end of Dexter in the Dark.
- Dr. Darius Starzak is a former professor of religious philosophy at the University of Krakow. He was fired for membership in an illegal society, a cult worshipping Moloch, and was suspected in a string of child murders. Dexter shoots him dead at the end of Dexter in the Dark.
- Alexander "Zander" Macauley is the son of a rich family who owns citrus groves, a large ranch, and a business that Dexter says "[dumps] phosphates into Lake Okeechobee". Zander is publicly hailed as a philanthropist for employing homeless people to work on his family's ranch. In reality, however, Zander murders them and disposes of their bodies in large drums of acid, keeping a single shoe as a trophy. Zander is also connected to the cult of Moloch. While looking through Zander's tax and travel records, Dexter finds out that the ranch is in fact idle, and that Zander takes frequent, unexplained flights in his private jet. Dexter kills him in much the same way he (Zander) kills his victims, even wondering if he, too, should take a shoe as a souvenir.
- Kurt Wagner is a college student and a member of the cult of Moloch. He is responsible for several murders in which the bodies are beheaded, burned, and given ceramic bull's heads. One of his first victims is his girlfriend. He has a distinctive tattoo of the Aramaic letters MLK on the back of his neck. He is found killed in a fashion similar to his own victims.
Notably, Wagner shares his name with popular Marvel Comics character "Nightcrawler". It is unknown if this is coincidental or a deliberate homage to his Marvel namesake, given Nightcrawler's own religious background and demonic appearance.
- Dr. Wilkins is a professor at the University of Miami. He attempts to frame a colleague for the murders of the Moloch cult. He attempts to sacrifice Astor and Cody to Moloch, but Dexter intervenes and shoots him in the head.
- Brandon Weiss is a character from Dexter by Design who is suspected of stabbing Deborah and leaving decorated corpses all over Miami. After Dexter kills his partner Doncevic (whom it is implied they had a romantic relationship), he is contacted by Weiss with evidence that shows Dexter killing Doncevic who then focuses his attention on Dexter for revenge. At the end of the novel, Weiss kidnaps Rita and plans to publicly kill her at an art convention. Dexter arrives in time and frees Rita; during the struggle against Weiss, Dexter is overpowered by him; he is saved when Rita hits him from behind, causing Weiss to fall on his own power saw killing him.
- Alex Doncevic is a victim of Dexter's who appears in Dexter by Design. Dexter suspected him of stabbing his sister Deborah as well as displaying several decorated corpses around Miami. Dexter feels some semblance of guilt when he learns that Doncevic's fingerprints do not match the ones on the knife that stabbed Deborah and that the corpses were stolen from a morgue rather than killed.
- Lily Anne Morgan is Dexter and Rita's daughter in the books, replacing Harrison. Dexter is extremely protective of her, deciding to give up his night-wandering ways in order to raise her well. However, when he later suspects that he is being watched (by his brother, Brian), he decides that his kills protect Lily Anne from the evil in the world. She is born in Dexter Is Delicious.
- Mitchell, Sean (October 1, 2006). "So He’s a Serial Killer? A Guy Needs a Hobby". The New York Times. Retrieved 2007-10-21.
- "Dexter". Dexter. Season 1. Episode 01. 2006-10-01. Showtime.
- "Seeing Red". Dexter. Season 1. Episode 10. 2006-12-03. Showtime.
- "See-Through". Dexter. Season 2. Episode 04. 2007-10-21. Showtime.
- "The British Invasion". Dexter. Season 2. Episode 12. 2007-12-16. Showtime.
- "Astor Bennett in Dexter Season 7 [Set Photos]". Wordpress. 2012-08-21. Retrieved 2012-11-18.
- "Dexter Season 7 Episode 8 Official Synopsis". Wordpress. 2012-10-03. Retrieved 2012-11-18.
- "Father Knows Best". Dexter. Season 1. Episode 9. 2006-11-26. Showtime.
- "Born Free". Dexter. Season 1. Episode 12. 2006-12-17. Showtime.
- "Truth Be Told". Dexter. Season 1. Episode 11. 2006-12-17. Showtime.
- "An Inconvenient Lie". Dexter. Season 2. Episode 03. 2007-10-14. Showtime.
- Matt Fowler (2012-12-02). "Dexter: "The Dark... Whatever" Review". IGN Entertainment. Retrieved 2012-12-03.
- "Crocodile". Dexter. Season 1. Episode 02. 2006-10-08. Showtime.
- "Popping Cherry". Dexter. Season 1. Episode 03. 2006-10-15. Showtime.
- "Circle of Friends". Dexter. Season 1. Episode 07. 2006-11-12. Showtime.
- "Love American Style". Dexter. Season 1. Episode 05. 2006-10-29. Showtime.
- "Return to Sender". Dexter. Season 1. Episode 06. 2006-11-05. Showtime.
- "Shrink Wrap". Dexter. Season 1. Episode 08. 2006-11-19. Showtime.
- "It's Alive!". Dexter. Season 2. Episode 01. 2007-09-30. Showtime.
- "Dex, Lies, and Videotape". Dexter. Season 2. Episode 06. 2007-11-04. Showtime.
- "There's Something About Harry". Dexter. Season 2. Episode 10. 2007-12-02. Showtime.