The Joker’s third stage marks a return to his first stage, but he commits very few robberies. Instead, he became a homicidal maniac, killing his enemies and his underlings. The Joker begins his third stage of evolution in the comic “The Joker’s Five Way Revenge,” where he kills four of his goons that betrayed him. When Batman finally catches up to him, Joker is about to drop one of his former thugs, Hooley, into a tank of water. Hooley is a old cripple in a wheelchair, so he will drown. Joker then tells Batman “I’m not mean! He won’t drown-- No, he’ll be a meal for the shark I found half dead on the beach! Poor fishy was hurt by the oil spillage." If the shark was beached due to an oil spill, Joker must put enormous effort into cleaning and healing the shark, just to feed an insubordinate goon to it. Joker’s statement that he is not going to be mean to Hooley, and that, instead of drowning, Hooley will be eaten alive by a starved shark, is insane. This shows the Joker as a murderer, and a fairly gruesome one at that.
The Joker commits one of his most evil acts in The Killing Joke. In this comic, the Joker cripples Commissioner Gordon’s daughter, Barbara Gordon, and rapes her and takes pictures of her lying on the floor, bleeding and naked, and then forces the Commissioner to look at the photographs in an attempt to drive the Commissioner insane.
The Joker is trying to prove that it only takes one day to turn an ordinary man into someone as crazy as himself. Joker then goes on say that Batman had a “bad day,” just like he did. This is somewhat logical, and to make up for this sudden burst of sanity, Joker tells Batman that he remembers something bad happening to him, but he does not remember what. “Sometimes I remember it one way, sometimes another … if I’m going to have a past, I prefer it to be multiple choice." This also demonstrates the Joker’s third stage of evolution.