Lead actress Lauren Bacall said of this film to People magazine upon its theatrical release: "The fan is much more graphic and violent than when I read the script. The movie I wanted to make had more to do with what happens to the life of the woman - and less blood and gore."
Reportedly, the film originally was intended as a straightforward thriller starring Elizabeth Taylor and directed by Jeff Lieberman. However, the project was delayed and both left the picture.
Production was delayed during principal photography when the film's star, Lauren Bacall, contracted chicken pox. Also, the filming of a key scene in a subway station was delayed by the New York City transit strike.
Originally intended to be a psychological thriller, this film was heavily rewritten into a more violent, straight forward "killer thriller" following the success of Brian De Palma's Pulsions (1980).
The source novel, written by Bob Randall and published in 1978, which was before the cycle stalking of public figures became a major problem, was his first; its form is "epistolary," consisting of various letters between many of the characters.