Why did Mark Chapman kill John Lennon?

Why did Mark David Chapman kill John Lennon?

• Answer:

  It's very difficult to say there was a reason like it was an assassination, or there was some kind coherent design behind the murder.  Chapman was mentally ill and disengaged from reality.  There are those that point to his statements and the copy of the Catcher in the Rye in his possession, but this is not corporeal evidence.  The guy was bat shit crazy and believed in some way that John Lennon needed to be punished for something or be sacrificed for some troubling cause.  It's a particularly difficult moment in the histories of rock and roll, New York City, the U.S. and literature.  It makes me angry honestly, just thinking of the circumstances behind it and what we lost.  There was no "reason" for that event.