There has to be more to it. The home where he shot his parents AND their friends looks to be plenty large to allow him to live with his parents. And yet, after his mom picked him up from prison, he went to live with the parent's friends who he also killed.
I am curious as to what his criminal history was all about. Also, wondering if he was anti-social, on drugs, or just fucked in the head? Maybe his parents wouldn't let him live with them due to them having firearms in their home? Or, maybe they didn't want him setting up a Meth lab in their home? So, their friends apparently stepped up, and they ended up dead. What a shame.