Producer Walter Wanger served a four-month prison term for shooting agent Jennings Lang, whom he suspected of having an affair with his wife Joan Bennett. The experiences he had in prison so unnerved him that upon his release he resolved to make a film about what prison was "really" like, not the typical Hollywood prison film made by people who had never been anywhere near a prison or who had never had any experience with the justice system. He shot the film at California's Folsom Prison and used both guards and inmates as extras and technical advisers. Wanger's cast and crew also differed from the Hollywood "norm"; among them were actor Neville Brand, decorated Army veteran of WW II who earned a Silver Star in the Allied European campaign; actor Leo Gordon, another combat veteran who had once served a stretch in Folsom Prison for armed robbery; and then-production assistant Sam Peckinpah, whose father, Denver Peckinpah, was a widely known and respected law-and-order judge in northern California (and whose name alone was enough to get the warden to allow the film to be shot in Folsom).