Sukeban Deka: Dirty Mary (1974)

There's a peeping Tom stalking the women of Tokyo, taking compromising photos through their bedroom windows of them having affairs and using it to blackmail them into sleeping with him with the promise of destroying the negatives. When one of his targets fights back after he continues to blackmail her for months on end, he lashes out in defence, bludgeoning her to death. Now it is up to the tough-as-nails detective known only as "Dirty Mary" to hunt down the pervert.