Donald Flack Jr.
Donald "Don" Flack, Jr. is a fictional character on the TV series CSI: NY. He is played by Eddie Cahill.
Characterization
Detective Flack is portrayed as the legal muscle for the CSI: NY team, similar to the roles of his Las Vegas and Miami counterparts Jim Brass and Frank Tripp. He can often be seen interrogating suspects with a characteristic wit and sarcasm. Though not as highly educated as the CSIs (he only has a high school diploma), Flack is intellectual and trusts CSIs' judgment and respects their findings. Throughout the series, he defends them to skeptical colleagues, especially (c.f. episode 311, "Raising Shane"). In episode 203, "Zoo York," it is revealed he is allergic to cats (which is again mentioned in episode 503, "Turbulence").
In Communication Breakdown, it was revealed that he understands and speaks some degree of Irish. The extent of his fluency is not fully known.
Storylines
Flack is a homicide detective with the NYPD, known for both his dry wit and his determination to hunt down suspects (even to the point of chasing them down alleys and over rooftops). He was mentored by another cop, Gavin Moran, who he is later forced to arrest after it comes to light that Moran concealed evidence during the course of an investigation (episode 118, "The Fall"). He is at least a second-generation cop; Moran mentioned having worked with Don, Sr. as well. He is both a colleague and a friend to the members of the New York Crime Lab. After Stella Bonasera is attacked in her apartment by her unstable boyfriend, Flack gently helps her through when he comes to the hospital to take her statement (episode 221, "All Access"). His friendship with Mac Taylor is tested when Taylor uncovers evidence that one of Flack's men is a dirty cop and asks Don to turn over his memo notebook to prove it. Though Flack eventually capitulates, their relationship is a bit tense for a some time after (episode 308, "Consequences," episode 310. "Sweet 16"). Flack defends Taylor to Captain Gerrard, who is investigating Sheldon Hawkes, the prime suspect in a robbery-homicide, after Taylor locks himself in the interrogation room with Sheldon. Flack affirms that Gerrard would do the same for him (Flack) (episode 311, "Raising Shane"). He is also close to Danny Messer, attempting to offer him some sound advice in episode 121 ("On the Job") when it appears that Danny accidentally kills an undercover officer. It is also assumed that Danny and Flack spend some of their downtime together as friends, in the very first episode Season 1, episode 1 Danny is exiting an interrogation room and casually says to Don "Hoops on Saturday, Flack. Don't forget." They are seen together at a basketball game in season 4. They also meet up for drinks and pool in episode 323, "Comes Around," and have a heart-to-heart talk about their jobs and why they do what they do.
Mutual interest between Flack and Detective Jessica Angell has been hinted at in several episodes; first in episode 407, "Commuted Sentences." This was finally proven when they locked lips at the end of season 5 episode "Dead Inside". In Rush to Judgement, the professionalism of their relationship was questioned while Flack was under investigation by Internal Affairs. They kept it quiet but revealed to the viewers they were indeed "seeing each other".
Flack is emotionally affected when Angell is shot and killed in the Season Five finale "Pay Up". His grief over her murder causes him to kill her killer in cold blood when he finds the shooter alone. The shooting is never questioned, but his grooming and appearance have since suffered; he shows up to work in sweatshirts and jeans, as opposed to his usual ties, dress shirts, and sport coats, and Stella notices that he has stopped shaving. When Cliff, Angell's father, played by James Martin Kelly, runs into him at the station one day, he comments that he hadn't seen Flack since Angell's funeral. Cliff invites Flack over to his home for dinner on what would have been Jess' birthday. Flack accepts the invitation, but is unable to let himself join the festivities; after sitting in his car outside the Angell home for a few minutes, he drives away without anyone in the house knowing that he had been there.
On the job
In episode 224, (Charge of this Post) Flack is critically injured when a bomb goes off in a building he and Mac are evacuating. Until their rescue, Taylor is able to keep Flack alive using a shoelace and prior experience in the Beirut barracks bombing. Flack remains unconscious for the remainder of the episode, but has since fully recovered, his concerned colleagues (especially Mac) standing vigil at his bedside. When Flack returns to work, his friends tease him about using his "battle wounds" to impress the ladies (episode 301, "People With Money").
Later, Flack is instrumental in the safe resolution of a crisis when he and another officer successfully rescue the infant daughter of an angry and upset young deaf man holding hostage the baby and his dead girlfriend's mother. While Mac Taylor distracts the man on one side of the car, Flack and the other officer sneak up on the other and take the child out through the window, whereupon Taylor is able to safely disarm the man. Flack then returns the baby to the care of her relieved maternal grandparents (episode 312, "Silent Night").
When the aforementioned arrest of Flack's subordinate results in the release of a serial killer, Flack berates Mac, who angrily counters that they both want the man back behind bars. They put aside their indignation to collar the murderer once more. Flack is mere feet away when the man plummets from a roof, handcuffed, and lands on a police cruiser, fatally wounded. Looking up, he sees Mac staring down at him from where the suspect fell (episode 321, "Past Imperfect").
As a child, Flack would sometimes play in a hedge maze in Queens, where he later investigates the death of a Chelsea University student, though he says that, by that time, he hadn't been there in years (episode 315, "Some Buried Bones"). His family, which includes a sister named Samantha and at least one brother, lived in Queens, and his mother used to make corned beef every Wednesday, which Flack later terms "paradise". Flack claims that he would "endure every one of [his] brothers' insults for one more taste of that paradise" (episode 404, "Time's Up"). He also says that he "was a Monopoly guy," (in response to a comment Stella Bonasera made regarding the board game Clue in episode 211, "Trapped"). Flack appears to have an appreciation for fine wine, instantly realizing the value of the bottles in a murdered chef's private cellar in episode 319, "A Daze Of Wine And Roaches."
In the season 5 episode Rush to Judgment, Flack comes under heavy investigation when a suspect dies in his custody during an interrogation. His badge is revoked and he is demoted to desk duty until the end of the episode, in which his name is cleared. During the investigation, the team is shown to support him, with Stella Bonasera saying that "[Flack] does everything by the book", and showing up to offer words of comfort to Flack while he's working. Also, Mac offers to take Flack out for a beer and to watch a hockey game, even though Mac doesn't like hockey himself,and supports Flack throughout the episode.