From what I've read, I'd have to agree. Here in New York, the first guy that comes to my mind is Anthony "Gaspipe" Casso. The guy was so batshit insane, that if he weren't a gangster, he probably would have been a serial killer. Then again, he probably fits the serial killer criteria anyway. He was very loyal to Tony "Ducks" Corallo, though. Much like Luca was loyal to Vito.