How many people did Stalin or Hitler kill with their own hands? Probably not many. That takes away a lot of cruel points by me. Now, Richard Kuklinski, on the other hand, did 100+ murders himself. Some were done as payback, for humiliating him, others for "crossing his border", but the majority were contract killings for the mob. This creepy sob is my nominee. John Wayne Gacy comes in a distant 2nd.
From wiki
Kuklinski first killed his number one enemy, Charley Lane, the leader of a six-boy gang, who often beat and harassed Kuklinski. Removing the rod that is used to hang clothes from his closet, Kuklinski waited until Charley Lane was walking alone, then beat him to death. Basing his actions on a magazine article he had read, Kuklinski cut off Lane's fingers and removed his teeth so he could not be identified, then threw the body in a frozen lake. The body was never found. Kuklinski then went in search of the other boys in the gang. He seized a metal pole from a trash can and beat all of them nearly to death. He said in the HBO documentary "Ice Man: Confessions of a Mafia Hit Man" (1992) that it was the day he killed Charley Lane that he learned it was "better to give than to receive".[1] According to his own statements, Kuklinski would hurt someone just for making him feel bad about something. His number one pet peeve was "loudmouthed people", because they reminded him of his father. He also stated that he had abused animals as a young child, such as killing cats and dogs by torturing them.
[edit] Association with the Gambinos and DeMeo
Association with the Gambino crime family came through his relationship with the mobster Roy DeMeo. Kuklinski stated that he started doing robberies and other assignments for the family, one of which was pirating pornographic tapes. But soon his talent for killing was realized and he stood out amongst his associates, standing 6 feet and 5 inches and weighing 300 lb. DeMeo decided to put him to the test. One day, he took Kuklinski out in his car and they parked on a city street. DeMeo then selected an apparently random target, a man out walking his dog. He then told Kuklinski to kill him. Without questioning the order, Kuklinski got out and walked towards the man. As he passed him, he turned and shot the man in the back of the head. From then on, Kuklinski was DeMeo's favorite enforcer.