Most morbid murder in history?

Jack the Ripper was the creepiest in my opinion. He killed people in the alleyways (with the exception of one victim killed in her own tiny room) of the most populated city on earth and no one ever saw him. After reading Phillip Sugden's creepy and brilliant "The Complete History of Jack the Ripper" I was amazed to find out how close he was to police officers walking their beat when he murdered women and disemboweled them, he truly took some extraordinary risks but never got caught. Very creepy, almost supernatural.