DetectiveSergeant Frank Tripp (Rex Linn) in the Homicide division of the Miami-Dade Police Department in CSI: Miami, (season 5-10; recurring seasons 1-4), is a homicide detective who regularly accompanies the team to the crime scenes. He joined the police force prior to applicants needing an undergraduate degree; although he is not as highly educated as the rest of the team, his knowledge and "street smarts" about the local area come in handy during investigations. He has a gruff appreciation for the capabilities of the CSIs and their excellent results. Consequently, he has a good working relationship with all the CSIs, particularly Calleigh Duquesne. He is divorced, with three kids (episode 118, "Dispo Day"). Before the season six premiere, Tripp is promoted to sergeant and it's seen that he has shaved his head. After passing the sergeant's exam, Tripp was required to spend some time in uniform on a patrol rotation. By episode #611, "Guerrillas in the Mist," he finished his mandatory patrol rotation and is back in Homicide, where his new title is given as "MDPD Homicide Detective Sergeant Frank Tripp".
Frank Tripp is originally from Texas. (Rex Linn, a Texas native later raised in Oklahoma, once missed a day's shooting of CSI: Miami to watch the Rose Bowl when the Texas Longhorns were playing.) Now that he's part of the MDPD, he's since become an avid Florida Gators fan. As a child, Tripp dreamed of being a firefighter. However, after his leg was shattered in a car accident, he fell in love with crime fiction during his many weeks' convalescence. Consequently, he joined the police force straight out of school, and was later transferred to MDPD's gang unit before moving to Homicide.
Tripp frequently accompanies Horatio Caine and his team of CSIs to crime scenes, especially those that involve dangerous gangsters and criminals, as well as assisting them in serving warrants.
The only one of Tripp's relationships that is mentioned in the show is a past marriage to his wife, Melissa, with whom he had three children, who remain unnamed. He divorced her after her alcoholism got out of hand. As their marriage deteriorates, she suspects him of cheating on her, and she hired a detective agency whose sole objective is to tempt men into cheating on their spouses and then report it. When the undercover investigator assigned to Frank is murdered, he becomes a suspect because the CSIs discover his fingerprints on her hotel room keycard. Eric Delko keeps Tripp's name quiet until he determines that Frank is not guilty of the murder, but Tripp is hurt by the suspicion nonetheless (episode 209, "Bait"). It was revealed in the season seven special features that Rex Linn stated "Give Frank a girlfriend or at least a dog."