Richard Burton and Edward Dmytryk made a weird little movie in 1972 called Bluebeard.
Burton plays Baron Von Sepper, a former WWI pilot that has joined a European fascist party, and is irresistible to women....REALLY HOT WOMEN! Thing is, Von Sepper can't get an erection, and because of this humiliation, he winds up killing each woman before the relationship is consummated.
It's suggested that Von Sepper may either be a homosexual, or that he is incestuously fixated on his dead mother (Dmytryk, at the end of his career may have thought he was cashing in on some post-Psycho boxoffice pull... he was wrong), thus explaining why he can't get an erection when confronted by - quite literally - the sexiest, nakedest, randiest, women in the world.
Me? I think he was just suffering from an early case of erectile dysfunction without a Viagra, Levitra, or pen*s pump in sight (did they even have arab straps back then?) I mean, think about this: you have, in their prime!!, Nathalie Delon, Raquel Welch, Marilu Tolo, and Agostina Belli aching for your touch, yet you can't get the blood flowing down there.
Murder? I think that's pretty justifiable...