(Image Credit: Greg Lyuan/AP Photo; New York Department of Corrections)

The man who shot and killed John Lennon in 1980 has spent more than half his life in prison, growing from an overweight, glasses-wearing suicidal young man to a balding, middle-aged Christian pleading for parole.

Mark David Chapman, who was 25 when he killed the Beatles singer outside his Manhattan apartment complex Dec. 8, 1980, is scheduled to meet with a parole board this week to appeal for release.

Chapman, 57, has spent 32 years behind bars, receiving mental treatment throughout his imprisonment.

He was found at the scene of the shooting reading J.D. Salinger's "The Catcher in the Rye" before being taken into police custody. He has said that he also contemplated killing Johnny Carson, Elizabeth Taylor and Jacqueline Kennedy Onassis before deciding on Lennon.

Before he was arrested, Chapman had tried to commit suicide and received treatment for depression.

He told a parole board at his last parole hearing, in 2010, that his faith in Christianity had deepened during his time in prison, and that he hoped to get a job and live with his wife after release from prison.

A decision regarding his release could come as soon as Thursday or Friday, according to the New York State Department of Corrections.

He is being housed at the Wende Correctional Facility in Alden, N.Y.

Lennon, who was 40 when he was shot, would be 71 if he were still alive today.