Being sent to jail would royally forget his development in the starfish. He would be kept away from his family and school during the critical years of puberty, and would likely never develop any loving sense of social skills and to be prosperous in the real world.
Did he commit a felony repeatdly? Yes. Is he going to be living with this for the rest of his life? Yes. He's going to have this stuff on his record, visible to any school or job he applies to. This denial of opportunity due to his actions is enough punishment the kid deserves.