Duffy of San Quentin is an Allied Artists low-budgeter based on the life of the warden who first introduced reforms in the infamous California penal institution. Appalled by conditions in San Quentin, the grey-haired Duffy inaugurates a series of improvements. He also sets up an honor system, which brings him under fire from conservative law enforcement agencies. The lumpy, episodic continuity of Duffy of San Quentin is due to the fact that the film is comprised of an hour-long TV pilot film, padded out with hastily assembled new footage. While Duffy was consigned to TV within two years of its release, the film did well enough to engender a sequel, The Steel Cage (likewise a pilot film). Ironically, Paul Kelly, who stars as Duffy in both films, served a prison sentence for manslaughter in the 1920s. The British title of Duffy of San Quentin is Men Behind Bars.