we have an opportunity, particularly with a guy like mark chapman who has agreed to open himself up for exploration and study in hopes of preventing other mark david chapmans from coming along. and people who criticize journalists for exploring people like that i think miss the point. >> it gives him publicity for this horrendous act he committed. the killer has become as famous as the people they killed. and it's really unfortunate. >> as with almost any famous tragic event, conspiracy theories have sprouted up regarding the shooting of john lennon. the prevailing scenario has mark david chapman as a patsy, programmed by mysterious government operatives to kill lennon. >> there was absolutely no evidence suggesting that he was assisted or aided by any other person. he was simply someone that acted alone and without assistance of other people. >> i've been through every fbi document in john's file.