Larry was an annoying little twerp. If he crossed the line into aggressive harassment, then discipline was needed.
Methinks little Brandon was insecure and needed to prove his manhood. He won't be the first to go to the pokey for letting testosterone get in the way of reasoning (nor will he be the last).
It went far beyond annoying, and with the apparent approval of an assistant principal.
So, what would you charge him with. Involuntary manslaughter might be appropriate. Never going to get first or second degree murder in this situation.