Ringo: The Lone Rider (1968)

Original title: Dos hombres van a morir

A town is being terrorized by a gang of marauders led by Bill Anderson, a clever bandit boss. The town's leadership is deciding to do something against the problem, but it does not believe bringing in the military will be a solution. It is agreed upon that they will request help from the well-known Pinkerton agency. At the same time, Ringo, a gunslinger, is chasing after the bandits. He suspects a deeper-sitting conspiracy than random bandit assaults. He joins forces with the newly arrived under cover Pinkerton agent, to uncover a plot between a local businessman, the Mexican revolution and bandit's heist loot of gold. But the bandits have long planned to move on. Disguised as Mormons, they are moving west to start a new life of farming during the day and robbing stage coaches at night. Ringo and the agent track them down....