Lawless Border (1935)

Border Patrolman Bill Roberts, posing as outlaw Whitey Jones, and his Mexican pal, Sanchez, through trickery, join a band of smugglers and revolutionists. Bill meets Mary Warren, sister of gang leader Jack Warren, whom Mary believes is trying to make good in honest ventures. Bill falls in love with Mary and tries to get her away before the roundup of the bandits. The gang learns that Bill and Sanchez are government men and trick them into the rebel's headquarters, where they are sentenced to die as traitors. Bill gets away and, while the Border Patrol is rounding up the gang, rides to the Warrens' house. He meets Jack and orders him to surrender. Mary, trying to protect her, she thinks, innocent brother shoots Bill. Jack realizes his sister's predicament and confesses and surrenders to the barely-wounded Bill.