Police officer Vic Mackey and the Los Angeles Police Department attempt to rid the city of crime, using their own unconventional, and often illegal, methods.
Vic sets out to stop stolen military weapons from fuelling a gang war, but he is unaware that his act threatens to expose him as the Armenian mob money theft mastermind.
Vic promises a gang lieutenant a top job if he agrees to set up his boss, and Dutch and Claudette's investigation into a gang shooting points to an unexpected triggerman.
A prostitute wants to Vic to punish her former pimp, and Dutch arrests a sex offender in an elderly woman's rape.
The rivalry between the Strike Team and the Decoy Squad heats up as they compete to find a murder suspect.
Dutch and Claudette continue to pursue a rapist who is targeting elderly women, and a gang arrest threatens to expose the Strike Team's involvement in the money train heist.
Officer Hisk becomes a prime suspect in the murder of his ex-wife and son.
A missing persons investigation uncovers a graveyard for illegal immigrants working in an illicit drug lab.
Vic is enlisted to save his rivals on the Decoy Squad when their undercover operation is at risk of exposure.
A lynching threatens to ignite a race war between Farmington's black and Latino gangs.
Aceveda turns up the heat in his search for a gangster who sexually assaulted him.
Dutch tries to understand the mindset of the rapist now dubbed The Cuddler, and Vic enlists Danny for an important undercover assignment.
The pursuit of a gang hitman pits Farmington's tight-lipped Korean community against the police.
Vic tries to sidetrack the money train investigation, and Claudette goes undercover to crack a child pornography ring.
The Strike Team are threatened with exposure in the money train heist, and Claudette goes it alone to find evidence of a public defender's drug addiction.
As Vic goes after Margos, Claudette risks her career to see that an innocent man is freed from prison.