Frontier Marshal (1939)

In the frontier town of Tombstone, Arizona, the charismatic Wyatt Earp is a pistol-toting sheriff who earns the respect of almost everyone he encounters. John 'Doc' Halliday, however, poses an unusual challenge to the lawman when he flouts local rules with his illegal business ventures. But the sheriff finds himself acting on Halliday's behalf when the latter is slain, leading to the famed gun battle at the O.K. Corral. Western, starring Randolph Scott, Nancy Kelly and Cesar Romero, who later found fame as The Joker in TV's Batman.