Best of the Badmen (1951) Robert Ryan, Claire Trevor, Jack Buetel

After the Civil War, Union Major Clanton captures survivors of Quantrill’s Raiders, and gets them clemency at the cost of shooting a mob member. Convicted of murder by a kangaroo court, Clanton escapes and joins the former raiders in a gang devoted to robbing everything protected by the corrupt detective agency of his enemy Fowler; culminating in a personal showdown.