Chapter 27

The movie takes place in the three days leading up to Lennon's assassination and is intended to be a deep exploration of Chapman's psyche, without putting substantial emphasis on the murder. The title "Chapter 27" suggests a continuation of J.D. Salinger's classic novel The Catcher in the Rye, which ends on chapter 26. Chapman attempted to model his life after Holden Caulfield, the main character of the book and was carrying a copy when he shot Lennon.

According to the Spanish-language newsweekly Proceso, and other Latin American publications, the title was also inspired by Chapter 27 of Robert Rosen's book Nowhere Man: The Final Days of John Lennon. Rosen's book explores the numerological meaning of 27, “the triple 9,” a number of profound importance to John Lennon. Lennon was obsessed with numerology, particularly Cheiro’s Book of Numbers, and 9 and all its multiples. Lennon was born October 9, 1940. His son Sean Lennon was born October 9, 1975. His wife Yoko Ono was born February 18, 1933. His songwriting partner with the Beatles, Paul McCartney, was born June 18, 1942. Lennon wrote such songs as Revolution 9, Number 9 Dream, and One After 909. Lennon received his green card, after a long legal battle, on July 27, 1976. Though Lennon was murdered in New York around 11 p.m. on December 8, 1980, it was already December 9 in England, the country of his birth. It was Chapman’s goal, according to Rosen, to write Chapter 27 "in Lennon’s blood."

The plot of the movie itself was drawn from the Chapman biography Let Me Take You Down, by Jack Jones, who is given a screen credit. Let Me Take You Down, however, provides no information on the numerological meaning of Chapter 27, and fails to show how Chapter 27 played into the heart of Lennon’s obsession with numerology, Cheiro, the number 9, and all its multiples.