While his previous film Fúria (1936) -- his first American film -- had gone down well with critics, the Hollywood brass were unsure what to make of Fritz Lang and his politicized films. To the rescue came his Fury star Sylvia Sidney, who loved working with him and urged her producer Walter Wanger to consider him for the directing job on this film. Ironically, Lang gained a reputation on this film for being difficult to work with, resulting in his not working for another 18 months.
PCA director Joseph Breen objected to the robbery scene details which were against the production code. Specifically, he listed "no flash of a man's face contorted with agony, no showing of a woman lying on the sidewalk, no hurling of bombs, no cop lying on the street, his face contorted with pain, no truck crushing out the life of a cop, no terrible screaming, no shots of bodies lying around, no figure of a little girl huddled in death, no shrieks." The print received by the PCA ran 100 minutes, and it is clear from the released print that some of these items and other scenes were cut, and the PCA finally gave it an approved certificate.
Dialogue from this is sampled in the song "Pornography" by The Cure. It's at approximately 69 minutes into the film, from the gas station robbery on for about 45 seconds.
Screenwriters Gene Towne and C. Graham Baker were notoriously eccentric, frequently working in bras and bathing suits, and sending memos written on toilet paper.
One of the first uses of a metal detector in film when it detects a gun at the prison entry.