Listen...if you're a 120lb scrawny kid being picked on and potentially beaten up by 200lb douchebags what would you do? You can't punch them because they're too large and the chance that you inflict anything upon them is miniscule. While I think that murder is wrong, if the kid is fighting for his life to avoid turmoil, the so be it. The bully got what was coming to him.
I don't agree. If this kid was picking on him, beating him up, etc for years, the kid snapped. 12 is probably excessive, but I can't even imagine what that kid was feeling at the time.