Being a cop is hard, but it's even harder when you're pretending to be one. Two years ago, Miles Logan was at the top of his game, an expert thief who steals a $17 million dollar diamond when one of his his accomplices, Deacon decides that he rather keep all of it to himself, killing one member of Miles' crew and nearly killing Miles who manages to take refuge in a construction site. Hearing the sirens of approaching cops, Deacon is forced to flee and Miles hides the diamond inside an airshaft so that he won't be caught with any evidence.
After spending the next two years in jail on a minor charge, Miles immediately heads out for his score only to discover to his horror that the building has been finished and is now police department's new headquarters! Which leads to his newest and strangest gig; posing as a cop to break into police headquarters and find his diamond!
But with him being constantly dragged out of the headquarters to attend to police calls, Miles discovers that his prior criminal knowledge makes him an incredibly talented cop and his unconventional methods quickly win him the admiration and accolades of his fellow police officers including rookie Detective Carlson and veteran Detective Hardcastle.
Deacon however has learned that Miles has been released from prison and is busy tracking his former accomplice down to take his $17 million dollar payday.
Miles eventually finds the diamond in the Evidence Room airshaft and accidentally drops it into an intercepted heroin shipment. But before he can recover it, the FBI arrive to take possession of the heroin. Desperate, Miles does some fast talking to convince the FBI and his fellow police officers that he has a plan to arrest the heroin smugglers themselves but he needs the heroin itself to gain their trust.
Eager to arrest the smugglers, the FBI agrees to his plan but the sting operation goes badly as the smugglers don't believe Miles and things go from bad to worst when Deacon crashes the party and a shootout ensues and Miles saves Carlson's life. Deacon steals the truck with the heroin shipment and races for Mexico with Miles trapped in the back. In a fierce struggle, Miles manages to force the truck to crash and then kills Deacon in self defense.
Afterwards, Carlson admits that he knows that Miles isn't a cop but he is still his friend and even if he is in possession of stolen property, Miles happens to be outside his jurisdiction as he is inches across the border of Mexico. A grateful Miles shakes hands with Carlson and departs with his diamond.
- Martin Lawrence as Miles Logan
- Luke Wilson as Detective Carlson
- Dave Chappelle as Tulley
- Peter Greene as Deacon
- Nicole Parker as Melissa Green
- William Forsythe as Detective Hardcastle
- Graham Beckel as Rizzo
- Robert Miranda as Glenfiddish
- Olek Krupa as Jean LaFleur
- Saverio Guerra as Benny
- Richard C. Sarafian as Uncle Lou
- Tamala Jones as Janiece
- Julio Oscar Mechoso as Detective Diaz
- Steve Rankin as FBI Agent Gray
- Carmen Argenziano as Captain Penelli
- John Hawkes as Eddie