The original script called for Leo Kessler to wrestle Warren Stacy to the ground in their final confrontation. Charles Bronson said he wasn't getting that "up close and personal" with a naked man.
The film was made in 1982, two years before DNA started to be used in criminal investigations.
Playboy Playmate Jeana Keough said she was really upset when Charles Bronson's told her during filming that he had wanted her to play his daughter, but the filmmakers told him she was too tall. In reality, she was 5'7", the same height as the actress they did cast, but she had lied about her height on her Playboy modeling profile saying she was 5'9". That lie cost her a much better role.
After attending a screening of the film, producer Pancho Kohner took Charles Bronson and his wife Jill Ireland to a trendy sushi restaurant to celebrate. During the dinner, Kohner noticed that Bronson was quiet and seemed down. Thinking he didn't like the film, Kohner told him to cheer up and that it was a good film. Bronson told him that it wasn't the film, he hated sushi.