"A good lowdown drama on a par with director Karlson's 1955 exposé docudrama The Phenix City Story. But K.C. has a more developed story line than Phenix City, a more exotic setting (Mexico), and a super noir group of actors...The story is pretty slick...George Diskant's powdery black-and-white photography traces the events streakily, making perfect use of the mood, forcing eeriness on us; and unrelieved visual stress. In this way Kansas City, Tijuana, and Barados have a uniformity of tone, giving us the bad side of the picture in which everyone already has one foot in the grave." (Barry Gifford) The plot, which begins with a masked robbery, is propelled by twists and reversals of identity: innocent ex-con John Payne takes on the moniker of a mobster in order to track down the gang that framed him, while crooked K.C. cop Preston Foster poses as a stand-up kind of guy throughout. "Each man, in turn, becomes the deterministic key to the other's destiny with Foster, the noir antagonist, the appropriately last victim of the fatal mechanism that he set in motion." (Silver & Ward, Film Noir)