What book was Mark David Chapman carrying with him when he killed John Lennon on December 8th, 1980?

When I first read Catcher in the Rye, I read it because it’s popular. It seemed like a must-read, and it came highly recommended ... By the end of this second read through, I wanted to know what was really wrong with Holden Caulfield. I also found myself incredibly curious about the novel's author, J.D. Salinger ... On December 8th of 1980, John Lennon was shot by Mark David Chapman. Outside of Lennon’s Manhattan home, police officers arrived to the scene to find Chapman casually flipping through his copy of Catcher in the Rye. During the case, when asked why he chose to kill John Lennon, Chapman stated "because he was famous". Chapman later claimed that he believed Holden Caulfied would have killed John Lennon because he was a "phony" ... He is quoted as citing the novel as his motive. Before his sentencing, Chapman read a passage from the novel in the courtroom. He thought of himself as the "catcher in the rye of his generation".