Kill and Pray (1967)

Directed by Carlo Lizzani

A Mexican community is slaughtered by Confederate troops; the lone survivor, a boy, is taken in by a preacher. Years later, the boy is now a soft-spoken, devout young man with perfect shooting skills (despite being a pacifist). On his journey to help his half-sister out of a complicated situation, he crosses paths with the men who killed his family, unbeknownst to him.