David Edwin Mason killed the elderly, often robbing them of paltry amounts of money. He also killed his elderly male lover who purposefully gave him a sexually transmitted disease. Mason was suicidal from a young age, probably because he was physically abused by his religious fundamentalist parents, and once tried to kill himself by self-immolation. He was executed by gas in San Quentin State Prison in January of 1994. Bill tells Matt about his observations of David Mason, having served on death row with for several years.