Killed by one bullet to head. In his own house. He has been assasinated by a professional Hitman working for the same mafia. Jason was now left alone. He had nothing left. No friends, no family, no money, also mafia was after him. Jason started drinking - he became an alcoholic.
His life wasn't worth anything now. But once he had a fight with some guy at a night club. The club manager was fascinated of his fighting skills and anger.
He hired Jason as his own loan shark. He did his job well, and was promoted to a bodyguard. His manager once found out about his past and problems with the mafia
Jason became on of his best employees. Eventually, Jason's manager found out about his problems with the mafia. Jason was one of his best employees. He was like son to him.
Manager sent his people to take care of the mafia, and since then Jason had never heard of the Mafia again. He could now live peacefully again. After many years of work as a bodyguard, Jason decided to do something else. He ,wanted to help others, maybe to save lives. He wanted to make sure that mafia wouldn't ruin anymore innocent lives. He was ready to do anything to stop the criminals of Los Santos, to put them to where they belong - behind the bars. This is when he decided to join Los Santos Police