Love this guy. He's a hell of an actor.
Beauty really is personal. But, a truly gifted actor who is not attractive will still stand out. Because "natural" talent is extremely rare.
But still, you can't get any "attractive" people, so how about this... You're killer is a once average looking guy, who went for plastic surgery, but it went wrong and he ended up horribly scarred. This drove him mad. After five years in the loony bin, he escapes and goes on a kill-crazy rampage, butchering ugly people and carving up their faces, to make them as 'beautiful' as he is...