American Nightmare

American Nightmare is a 1983 Canadian slasher film directed by Don McBrearty and starring Lawrence Day, Lora Staley, Lenore Zann, Michael Ironside, and Alexandra Paul in her feature film debut. It tells the story of a successful pianist investigating the disappearance of his sister in an urban decadence as a serial killer targets prostitutes and sex workers. The screenplay by John Sheppard, based on a story by John Gault and Steven Blake, was influenced by the rising crime rates in American cities throughout the 1970s and early 1980s.

Synopsis from Wikipedia, CC BY-SA 4.0. Everything below written here.