He is a Sociopath and will have to be watched for the rest of his life.
The kid, like all murderers, whether minors, need to be sent to their makers. The same with adult murderers. Kill them all, let God sort them out.
It is the only way to be sure, and they may have a chance to repent before their deaths. What is more just than having a date certain with death? No screwing around, and not asking for forgiveness, because you have to shit or get off the pot on that question. JMO....