Conversation so far:
what was the development on chapter 27?
the title was also inspired by Chapter 27 of Robert Rosen's book Nowhere Man: The Final Days of John Lennon (2000).
what else was it inspired by?
Lennon was deeply interested in numerology, particularly Cheiro's Book of Numbers, along with nine and all its multiples.
what was his biggest accomplishment?
book of Chapman's recollections of his act of violence.
Are there any other interesting aspects about this article?
The real Mark David Chapman is currently incarcerated at Wende Correctional Facility, on a guilty plea.

Question: why is he incarcerated?
Self-contained rewrite: why is Mark David Chapman incarcerated?