Watch Night Trap (1967) Official Trailer

A woman's desperate attempt to prove her husband's innocence after he has been sentenced to death for the murder of his mistress. She tracks down four men in the victim's life, one of whom she suspects may be the real murderer, and systematically destroys them. In the end, her obsession becomes madness and she has ruined her own life along with her victims' lives to save her philandering husband.