Mason was a prisoner aboard the Astral Queen and took part in a prison revolt aboard that ship. (Bastille Day)
Nothing is known about Mason's pre-holocaust life except that he was a prisoner aboard the Caprica-bound Astral Queen, on his way to have his parole eligibility assessed. He seemed to have an inferiority complex and was offended by Cally's lack of interest in having a conversation with him while she was being held as a hostage. He later removed her from her holding cell and attempted to rape her. Cally bit part of his ear off in self-defense and Mason responded by shooting her in the stomach. Later in rage about being bitten, he tried to kill Cally but was slain by Captain Lee Adama before he had a chance.