Trivia

Brian De Palma really wanted to direct this film but his producers could not obtain the rights to the material, so he made Dressed to Kill instead.

The LA punk band The Germs recorded five or so songs expressly for the soundtrack to this movie, although in the actual event, only "Lion's Share" was actually used. During the recording sessions, director William Friedkin was so energized by the Germs' playing that he took to doing the "pogo" dance around the engineer's booth.

In an effort to make the scenes of gay "leather bars" as real as possible, actual gay bars for men were used in the film that existed in New York City at that time. These locations are in the lower west neighborhoods in the meat packing district of Manhattan, most of which remain open to this day. Movie extras in full black leather and chaps, including other provocative sexual attire, were actual gay patrons of the bar recruited for the scenes a few days before filming began. The extras were instructed to act as they would normally act in gay bars, but to tone down sexually-oriented activities because of the likelihood these acts would give the film an "X" rating.

Karen Allen was never shown a complete script before she worked on this film. Director William Friedkin deliberately kept the actress in the dark about the events of the film since her character Nancy wasn't supposed to be aware of what was happening to Al Pacino's cop as he explored the gay underworld.

James A. Contner's first job as a director of photography. William Friedkin gave him the opportunity after having been impressed with his work as a camera operator.

The film is based on a series of real murders of homosexual men that took place between 1962 and 1979 in New York City.

The film was part of a breakthrough cycle of mainstream Hollywood studio movies featuring gay partnerships and drag characters. Others included Making Love, Victor Victoria, Partners, Tootsie and Personal Best.

In 1977 and '78, New York homosexuals were terrorized by a series of "bag murders," in which six male victims were mutilated and dismembered , their remains wrapped in black plastic bags and dumped in the Hudson River. Some of the grisly fragments washed up on the New Jersey shore, others coming to ground near the World Trade Center. Police traced items of recovered clothing to a shop in Greenwich Village, catering to gays, and distinctive tattoos identified one of the victims as a known homosexual. Lacking identities and confirmed cause of death in several cases, the crimes were not officially classified as homicides, but were listed as CUPPI's - circumstances undetermined pending police investigation. A solution in the case derived from evidence collected in an "unrelated" case. On September 14, 1977, film critic Addison Verrill was beaten and stabbed to death in his New York apartment. Charged with the slaying, Paul Bateson, a 38-year-old X-ray technician, confessed to meeting Verrill in a Greenwich Village gay bar. After having sex at Verrill's flat, Bateson crushed his victim's skull with a metal skillet, afterward stabbing Verrill in the heart. Convicted of the homicide on March 5, 1979, Bateson drew a term of 20 years to life in prison. While in custody, awaiting trial, Paul Bateson bragged of killing other men "for fun," dismembering their bodies, and dropping the bagged remains in the Hudson River. Detectives satisfied themselves of Bateson's guilt, but he was never charged, and the "bag murders" - that later inspired the movie Cruising - remain technically unsolved.