What movie was jack nicholson a cop in?

Jack Nicholson played a cop in several movies, but the most famous one is likely "Chinatown" (1974) where he plays Jake Gittes, a private investigator who becomes entangled in a web of corruption and murder in 1930s Los Angeles.

Here are some other movies where Jack Nicholson played a cop:

* "The Last Detail" (1973): He plays a tough, but sympathetic Navy Master Chief Petty Officer assigned to escort a young sailor to prison.

* "The Pledge" (2001): He plays a detective who is obsessed with finding a killer after a young girl is murdered.

* "Ironweed" (1987): He plays a drifter who returns to his hometown and becomes entangled with the local police.

Let me know if you'd like more details about any of these films!