For that matter they ought to also arrest and indict the school administrators who met with this lunatic kid and his parents just a few hours before he went on his killing rampage. Would love to know what information the school had on this kid and ended up doing nothing when they had the chance to intervene effectively. Suspect the kid let be known he had guns and intended to kill. They could have called the police and had him arrested for making terrorist threats. IMHO these school officials are afraid that if they take action, the parents will sue and that would affect their careers. They need to grow a pair.
If they find out the kid had mental issues and the parent’s, the school and everybody that knew was silent about it I’d arrest them all. It’s amazing how many people knew about the instability of these mass shooter and never said a word.