Martin Riggs is an L.A. cop with suicidal tendencies and Roger Murtaugh is the unlucky police officer with whom Riggs is assigned. Together they uncover a huge drug-smuggling operation, and as their success rate grows so does their friendship.

In the coastal town of Los Angeles, a gang of bank robbers call themselves the ex-presidents. commit their crimes while wearing masks of ex-presidents Reagan, Carter, Nixon and Johnson. The F.B.I. believes that the members of the gang could be surfers and send young agent Johnny Utah undercover at the beach to mix with the surfers and gather information. Utah meets surfer Bodhi and gets drawn into the lifestyle of his new friend.

Amidst a territorial gang war, a sophisticated alien hunter stalks the citizens of Los Angeles and the only man between him and his prey is veteran L.A.P.D. officer, Lieutenant Mike Harrigan.