Berserk (1967)

As the co-owner and ringmaster of a traveling circus, Monica Rivers (Joan Crawford) is always preoccupied with filling seats. Following the accidental death of a tightrope walker, Rivers is pleased to see her profits increase and callously unconcerned with the demise of her employee -- in fact, she soon hires handsome Frank Hawkins (Ty Hardin) to replace him. But when several more performers meet gruesome deaths, it becomes apparent they are no accidents, and there's a killer on the loose.