William Friedkin - film - 1980 - p. 218    

Directed by famed horror and action film director William Friedkin, Cruising takes inspiration from a novel, also titled Cruising, by Gerald Walker, in which a serial killer preys on gay men in New York City. In it, Al Pacino plays Steve Burns, a cop who goes undercover into the world of leather bars in hopes of solving the murders of gay men who have begun turning up dismembered in the Hudson River. The case, about which he can disclose little, puts a strain on his relationship with his girlfriend, and Burns also finds himself disturbed by the police department’s excessive use of force and ability to arrest individuals simply for being gay. Though Burns finds the alleged killer, an ambiguous ending throws both the outcome and the protagonist into question.

Legend has it that Friedkin had to present edited versions of the film to the MPAA 50 times in order to evade the dreaded “X” rating. The film is believed to have moved some anti-gay bigots to violence; weeks after its release, a shooter killed two patrons and injured a dozen more in a bar Cruising featured.

Key elements: crime, homosexuality, mental illness, teacher