John Lennon was an English musician, songwriter and activist. He gained global fame as the founder, co-lead vocalist and rhythm guitarist of the Beatles. Lennon's songwriting partnership with Paul McCartney remains the most successful in history.

He was trigically shot and killed by Mark David Chapman in New York City on December 8, 1980, who was a fan of the Beatles but later grew infuriated by Lennon's lavish lifestyle, the lyrics of "God" and "Imagine", and public statements such as his remark about the band being "more popular than Jesus". The J. D. Salinger novel The Catcher in the Rye took on great personal significance for Chapman, to the extent that he wished to model his life after its protagonist, Holden Caulfield, and planned to cite it as his manifesto. Chapman also contemplated killing other public figures, including Paul McCartney and Ronald Reagan.

Chapman's legal team initially intended to mount an insanity defense based on the testimony of mental health experts who said that he was in a delusional psychotic state at the time of the shooting. However, he was more cooperative with the prosecutor, who argued that his symptoms fell short of a schizophrenia diagnosis. As the trial approached, Chapman instructed his lawyers that he wanted to plead guilty to murder based on what he had decided was the will of God. The judge granted Chapman's request and deemed him competent to stand trial. He was sentenced to a prison term of 20 years to life with a stipulation that mental health treatment would be provided.

In 2000, Chapman became eligible for parole, which has since been denied 14 times.