Jean Hagen's last movie.
Robert Aldrich was a candidate for directing.
Bette Davis originally wanted James Philbrook of The New Loretta Young Show to play the role that eventually went to Karl Malden.
Lana Turner turned the film down because she didn't want to play twins.
As Karl Malden's police sergeant character leaves his desk, he calls for a colleague named "Sekulovich" to toss him his hat. Malden's birth name is, in fact, Sekulovich.
The original script was written in 1944 and sat on the shelf at Warner Brothers until 1963 when at long last it was finally in production.