The Gay Amigo (1949)

Chasing Mexican bandits, the Captain sees Cisco and Pancho ride away. Assuming they are the bandits he captures them and then lets them go. He has them followed figuring they will lead him to the entire gang. Cisco learns the editor and the blacksmith are the leaders. He makes the blacksmith think his partner double-crossed him and then joins up with him as his new partner planning to lead the entire gang into a trap.