He has been free because he was a “juvenile” when he shot up the school. That frees him when he reaches adulthood. Unfortunately for him, he will likely be arrested for the merest infractions for the rest of his life and will spend a lot of time in prison. Such a person has to live a life of utter rectitude to hope to avoid prison, and needs to get himself to another state or country. Such a one, however is probably not very smart and will not avoid drugs and whatever strikes his fancy.
One can only hope that his risk taking behavior kills him.