Mitch Preston (ROBERT DE NIRO) in a detective working for the L.A.P.D. who's been on the force for 28 years. Trey Sellars (EDDIE MURPHY) is a police officer with considerably less experience and a hankering to be an actor. When Trey gets into the middle of Mitch busting two criminals -- Rerun (TJ CROSS) and Lazy Boy (MOS DEF) - and lets one of them get away when he mistakes Mitch for a thug, the detective is none too happy and he takes it out on a nearby TV cameraman who's in the way by shooting his camera.
Having seen that display of hostility, TV producer Chase Renzi (RENE RUSSO) comes up with the idea for a new reality show revolving around the life of a cop like Mitch. He obviously has no interest in appearing in such a show, but Capt. Winship (FRANKIE R. FAISON) informs him that the only way they'll get a network lawsuit dropped against them is for him to do so.
Chase realizes that Mitch will need a partner and obviously draws the attention of Trey when she puts out a casting call for such a character. Mitch adamantly refuses to allow Trey to be his partner, but Chase, who likes the thought and sight of antagonistic sparks between the two, makes it happen. With the aid of her assistant Annie (DRENA DE NIRO) and director Williams Shatner (WILLIAM SHATNER), Chase starts production of the show, hoping to make Mitch and his environs more TV friendly.
As he reluctantly goes through such training and dealing with Trey as his camera-friendly partner, Mitch tries to solve a series of crimes involving Cesar Vargas (PEDRO DAMIAN) and the massive artillery he uses during them, all while becoming a celebrity due to the airing of the TV show that's been named Showtime.