j.d. salinger and "catcher in the rye" did not cause me to kill john lennon. in fact, i wrote j.d. linger i got his box number from someone, and i apologized to him for this. >> in october 1980, chapman turns his attention towards phonies when he reads about the release of "double fantasy." >> this thing started with the dakota, i'm angry at seeing him on the dakota. and i say to myself, that phony, that bastard, i got that mad, i took the book home to my wife and i said, look, he's a phone-n. >> this is his calendar from december of '89 to december of '90. >> writer jim gaines spent hundreds of hours between 1984 and 1985 interviewing mark chapman. >> and you can see it becomes crazier and crazier with crossings-out and things to do. >> chapman told gaines, his mind had been like a war zone occupied by opposing forces he described as the big people and little people. >> he had a whole population of little people living in his head. to whom he gave instructions who had meetings about what his activities would be. mine, it was extreme. >> seething with anger, chapman buys a five-shot

j.d. salinger and "catcher in the rye" did not cause me to kill john lennon. in fact, i wrote j.d. i got his box number from someone, and i apologized to him for this. >> in october 1980, chapman turns his resentment against phonies, towards john lennon, when he reads an article about the upcoming release of "double fantasy." >> this thing started, larry, when i got angry at lennon. i found a book in the library that showed him on the roof of dakota. you're familiar with the dakota. it's a very nice, sumptuous building. and i'm angry at seeing him on the dakota. and i say to myself, that phony, that bastard. i got that mad. i took the book home to my wife and i said, look, he's a phoney. >> this is his calendar from december of '79 to december of '80. it leads you all the way through his manic months before lennon's death. >> writer jim gaines spent hundreds of hours between 1984 and 1985 interviewing mark chapman. >> and you can see it becomes crazier and crazier with crossings-out and things to do. >> chapman told gaines that for years his mind had been like a war zone, occupied