Cop Land is a 1997 American drama film written and directed by James Mangold with an ensemble cast featuring Sylvester Stallone, Harvey Keitel, Ray Liotta, Robert De Niro, Robert Patrick, Peter Berg, and Michael Rapaport.

In the fictional town of Garrison, New Jersey, located across the Hudson River from New York near the George Washington Bridge, a large number of residents are New York City Police Department officers.

Murray ‘Superboy’ Babitch (Michael Rapaport), Lt. Ray Donlan’s (Harvey Keitel) nephew, gets sideswiped on George Washington Bridge by a couple of African-American teens. Thinking that they had fired a gun at him, he returns fire and they are killed in an ensuing crash. Worried about a possible racial incident, Ray decides the best solution is to fake Superboy’s death by suicide by jumping off the George Washington Bridge. When another corrupt cop Jack Rucker (Robert Patrick) is caught red-handed trying to plant a weapon on one of the deceased motorists to justify the shooting, their fellow corrupt cops (John Spencer and Arthur J. Nascarella) fear Superboy will testify to internal affairs about police corruption.

Smelling a cover-up in Superboy’s “death”, IA investigator Moe Tilden (Robert De Niro) asks Sheriff Freddy Heflin (Sylvester Stallone) of Garrison, NJ to provide internal affairs with information on the corrupt cops. Even though they are corrupt and work in a different city, Freddy views them as allies and brothers, able to accomplish what he could not. His reluctance to betray his friends derails the investigation.

Although the cover up at first seems successful, Ray is told by his PDA President Vincent Lassaro (Frank Vincent) that without a body, the case will not stay dead. Ray reluctantly decides that Superboy should be killed. However, they botch the job and in doing so reveal to Freddy that Superboy is actually alive. Freddy is forced to confront the truth about his friends and try to bring them to justice.

Summary via Wikipedia.