Road Agent (movie, 1941)

Summarily accused of murder, drifters Duke (Foran), Pancho (Carrillo) and Andy (Devine) are tossed into the hoosegow, only to be released when their alibi checks out. Far from offended by his ill treatment, Duke agrees to take the job of sheriff, retaining Pancho and Andy as his deputies. The gruesome threesome then sets about to solve a series of mysterious Wells Fargo robberies