To Kill a Clown (1971)

To Kill a Clown (1972) is an early entry in the crazed Vietnam vet genre. A hippie couple goes to a secluded beachfront house to try to rekindle their love. The caretaker is the wacko ex-soldier Alan Alda, who decides to teach them what it means to be a man, which involves brutalizing them with his well-trained Dobermans. Blythe Danner, as a svelte youth, shows off a body that never looked as good again. Meanwhile, her hubby is busy moving rocks à la Alda's orders. He finally takes one of those rocks and smashes Alda's bonkers brain with it. And that's how you kill a clown.