The Metro-Dade Internal Affairs Division, or IAD, is a group of policemen specifically assigned to handle internal security; investigating allegations of wrongdoing by Metro-Dade officers, such as, but not limited to, police brutality, bribery, embezzlement of police funds (such as buy money), the lawfulness of any fatal actions, and other illegalities within the department.
Owing to their job investigating fellow police staff, IAD are often hated by other law enforcement divisions and viewed as 'traitors', and as such IAD officers can usually expect to be treated with suspicion and contempt. Their portrayal in fictional media is often scripted to emphasise this traitorous characterisation, with Internal Affairs agents appearing bullish, uncooperative, devious and devoid of compassion.
Several IAD officers have appeared on show:
- Ben Schroeder in "One Eyed Jack" -- Schroeder investigated allegations of bribery surrounding Crockett and Vincent DeMarco.
- Unnamed IAD officers in "Whatever Works" -- Internal Affairs investigated South Beach cops Tommy Solen and David Blakeney in the Santeria killing case.
- Louie Gallo and Ben Dokes in "The Dutch Oven" -- they investigated Crockett and Trudy Joplin regarding a shooting incident in which they allegedly fired without giving due warning.
- Earle Hodges in "Payback" -- Hodges was attempting to track down $3 million that was stolen from from the Fuente organization, allegedly by Crockett.
- Unnamed IAD officers in "Streetwise" -- Internal Affairs looked into Vic Romano's close association with prostitute Carla Cappoletti.
- Unnamed IAD officers in "Down For The Count (Part II)" -- Internal Affairs, much to the disgust of the Vice team, investigated Larry Zito's death to determine if it was a homicide or merely a self-inflicted overdose.
- Unnamed IAD officers in "Theresa" -- Internal Affairs also investigated Crockett's involvement in an explosion at an evidence warehouse and the associated death of two policemen.
- Officer Stroh in "Knock, Knock... Who's There?" -- he investigated the disappearance of $250,000 in departmental buy money, with Crockett and Tubbs the lead suspects.
- Walter Mills in "Vote of Confidence" -- Mills investigated the disappearance of gubernatorial candidate Tom Pierce after his meeting with Crockett and Tubbs.
- Officer Stroh reappeared in "Amen... Send Money" -- this time the officer investigated allegations of rape directed at Tubbs by Bill Bob Proverb disciple Faye Nell.
- Unnamed IAD officers in "Child's Play" -- Internal Affairs investigated the shooting of minor Jeffrey McAllister by Crockett.
- Walter Mills reappeared in "Bad Timing" -- the IAD agent gave hostile testimony in court against Crockett after his actions as Sonny Burnett.
- Between them, Crockett and Tubbs were investigated a total of ten times by IAD during the course of the show (and exonerated in each case). According to Tubbs, they came under scrutiny from Internal Affairs so many times that the Division must have had "a permanent poker with our names stenciled on it".