Funny that Chapman, Hinckley and Edward Richardson all look alike.If somebody killed Chapman they'd be killing a victim. If you read Fenton Bresler's book Who Killed John Lennon? you'll find there's a lot of unsolved evidence showing Chapman was being controlled by people who were steering him towards killing FBI person of interest John Lennon. Before you scoff at this you have to read the background on CIA's MK-ULTRA mind control experiments under Sydney Gottleib and CIA's Technical Services Divison. Bresler found evidence that disaffected apartment house maintenance man Chapman showed sudden interest in Catcher In The Rye right in perfect synch with John Lennon's unannounced career comeback. Chapman had no way to know this since Lennon hadn't told anyone. FBI had admitted it bugged Lennon's apartment. Bresler's most condemning evidence was proof of forgery of Chapman's United Airlines travel ticket. This type of manipulation could only be done at the CIA level.
Once you realize Sirhan Sirhan was hypnotized to assassinate Bobby Kennedy you can understand that Chapman's hypnotic mind control was a given with such a strong political target as Lennon. The leading expert in mind control hypnosis, doctor Herbert Spiegel of Columbia University, said Chapman possessed every sign on the checklist for mind control hypnosis.