The prison scenes were filmed at Stateville Prison in Joliet, Illinois, where the real Roger Touhy was incarcerated. The film was previewed at Stateville on July 12, 1943 with the Governor of Illinois (Dwight H. Green), and over 1,000 police officers and State's Attorneys from Chicago other Illinois communities in attendance. Touhy, who was suing 20th Century Fox (unsuccessfully it turned out) to prevent the films release, was not invited to the show, nor were any other prisoners, which was held in the prison chapel.