Today in 1981 Mark David Chapman officially entered a plea of guilty for the killing of John Lennon, and was sentenced two months later.  He's been in prison since then, with a parole hearing and subsequent denial every two years since 2000.

Chapman was a certified psychotic, afraid of his father in the military, bullied as a school kid, and a suicide "survivor".  He shot John Lennon four times in the back on the night of December 8th after getting his autograph six hours earlier.  After he shot him, he stayed and waited calmly for the police to arrive and presented the book Catcher in the Rye as his statement.  Ridiculous and un-explainable to this day.