The Renegade Ranger (1938)

The Rangers send Jack Steel to bring in wanted murderer Judith Alvarez. He is on hand when Sanderson's men attack and he saves her life. This gets him into her gang where he gradually realizes she is innocent and Sanderson is the one he is after. But ex-Ranger Larry is now one of her men and he reveals Jack's true identity. Jack is then slated to shortly have a fatal accident.