The Young Captives (1959)

Teen-age sweethearts, Benjie Whitney and Ann Howel, decide to elope to Mexico. Jamie Forbes, insane itinerant oil-field worker, who has killed his boss, runs on to them when they run out of gas and forces them to take him with them. On the way, he murders a blonde woman, at a gas station, who resents his attentions. Once in Mexico, he forces his attentions on Ann, while holding Benjie at bay with a switch-blade knife.