Trivia

When Rod Steiger turned up on-set, the make-up people had to quickly scramble, because he had just had plastic surgery to hide his age, and the wounds were still fresh on his face.

Despite the fact that this movie was running on schedule and under budget, The Cannon Group, Inc., and the production manager slashed several weeks from filming, and took away a hefty chunk of the budget. All of this was due to the fact that Cannon's previous line-up of movies had all severely underperformed.

This movie was made only because The Cannon Group, Inc. had wanted for some time to make a movie with Sir Roger Moore, in order to cash in on his James Bond popularity. Moore was able to persuade them to back this movie of Sidney Sheldon's 1970 novel, and to hire two of his best friends, writer and director Bryan Forbes and actor David Hedison. This movie was made on-location in Chicago with the supporting cast mostly obtained (very inexpensively) from the ranks of local theater actors, some of whom were making their first movie.

Rod Steiger was cast as Police Lieutenant McGreary, due to his Academy Award winning performance in In the Heat of the Night (1967), as Police Chief Bill Gillespie.

Production was mostly smooth, thanks to writer and director Bryan Forbes, but when Sir Roger Moore's mother fell ill in England, Forbes granted him a week off to go visit her. When he returned to the shoot, he discovered that producers Menahem Golan and Yoram Globus, the heads of The Cannon Group, Inc., had blasted Forbes for his kindness. From then on, the studio treated cast and crew poorly. Moore and Forbes, however, remained friends up until Forbes' death in 2013.