Let's keep in mind that this kid is thirteen years old. I don't know about the rest of you, but between 13 and say, 20 years old, I became an entirely different person. Cast your mind back to when you were thirteen - how smart were you really? How introspective? How many of the emotional/introspective tools you now have did you have then?
I'm reading a lot here about old values of retribution - what about the equally old value of redemption? Make the child (for that's what he is) pay for what he has done - pay back the people he has harmed.
At the same time he gets to know the victims of his crimes, the victims would get to know him. Yes that's important - it is far too easy to only ever see the bad guy as some amorphous monster; to see him as human, as a child - to be forced to acknowledge his humanity at the same time that the victim declares theirs. . .well something more than justice can come from that.
Pangloss