My blood is boiling as I read this! I'd have sued the school board for failing to provide your daughter a safe environment and negligence. Persistent abuse at this bully's hands, a known bully, several complaints from you and/or your daughter, thereby putting the school on notice. They were aware, they did nothing. If it walks like negligence and talks like negligence, well...

The mother in me has a different reaction, let's just leave it at that boy is lucky it wasn't my kid and that I didn't get a hold of him...