Tre croci per non morire (Three Crosses Not to Die (1968)

Three men, Jerry (Hill), Reno (Wood) and Paco (White), meet in the same prison and in their cell they find a Mexican boy condemned to death for murder. One night the three convicts are mysteriously released by a priest and the father of the Mexican boy who promises them a reward of $30,000 if they can find the real murderer within ten days. Certain that the Mexican boy is not guilty, Reno and the others organize a plan which leads to the unmasking of the real killers.