Brothers in the Saddle (1949)

Bad seed Steve Taylor is pulled out of a saloon by his brother Tim after Steve kills cheating poker player Hoyt Parker in self defense. Steve, who's been financing his gambling addiction with money from his fiancée, is convinced by Tim to give himself up for trial. Found guilty without crucial testimony of his innocence by saloon girl Flora Trigby, who has fled to Mexico, the two brothers make their getaway to a secret hideout, where Tim heads out to find Flora. Tim's enthusiasm for protecting his brother lessens when he returns with Flora and learns someone matching Steve's description has held up the stage and killed passenger Nash Prescott, Parker's co-partner and Steve's chief accuser at the trial.