Forged Passport (movie, 1939)

Dan Frazier is a U. S. Border Patrolman on the California-Mexico border whose hot temper and ready-fists keep him in trouble, both of which indirectly lead to the death of a fellow trooper. He resigns from the force in order to find out who was responsible. He believes it was a gang of smugglers, engaged in smuggling illegal aliens into the United States from Mexico, and in order to get inside the gang he fakes smuggling activities.