The writers used the name "Cornell" for the obsessive cop played by Laird Cregar, a tribute to noir writer Cornell Woolrich.
Immediately before shooting, a bottle of silver nitrate was accidentally spilled onto Carole Landis' lips by her dentist. As a result, her lips were blue for more than three weeks, posing an added challenge for the makeup crew.
The first noir film produced by 20th Century Fox.
In Darryl F. Zanuck's original concept of the film, it was to end with a Betty Grable song, but that idea eventually was discarded. "Daddy" (music and lyrics by Bobby Troup), plugged by Grable's character Jill in a store's music department, was cut from the film so that Twentieth Century-Fox could showcase Grable in a fully dramatic role. The shooting script had Jill working as a stenographer instead of promoting songs. In Grable's sole musical moment, Jill hummed a bit of the Pyotr Ilyich Tchaikovsky-based ballad, "The Things I Love" (music and lyrics by Harold Barlow and Lewis Harris), during a car ride with Victor Mature and Carole Landis's characters. Most of the ditty would be sung by Landis' character Vicky later in the movie. Footage of Grable performing "Daddy" still exists.
When Laird Cregar went on a ride-along with L.A. police during filming, he was caught up in a real shooting. Cregar also reported for work shortly after an emergency appendectomy, against his doctor's orders.