Chapman was sentenced to 20 years - to - life and has been denied parole nine times amid campaigns against his release .
Mark David Chapman , who pleaded guilty to murdering John Lennon in 1980 .
Mark David Chapman was sentenced to 20 years - to - life and has been denied parole nine times amid campaigns against Mark David Chapman 's release .
Mark David Chapman , who pleaded guilty to murdering John Lennon in 1980 .