I'm going to chime in on this, because I work in the Juv. Court system -- that's my job. I understand your angst, ILH. Properly done, the SCHOOL should have called law enforcement, if this happened on school grounds. Absolutely, talk to the school people to see if they have made any sanctions against the other kid (suspension; time after school, etc.) if this was an unprovoked attack. And if not, if the school doesn't take it seriously, maybe you should pursue it with LE. If it was near the school grounds, I'd suggest the same thing. Or if anything happens on a school bus or a bus stop -- same.
But I also see so much stuff where kids are just being kids, where a simple push and shove turns into a law enforcement call. And that is a waste of L.E. resources! The school should address it, and all the parents should address it, and work together for a resolution or appropriate sanction.
And I'm not saying this has anything to do with your situation at all, ILH, but I get so sick and tired of seeing referrals to charge juveniles on domestic violence charges when the parents have set down few or NO rules, or don't enforce them (preferring quiet time or time-outs), then suddenly wake up to the problems, but don't have the parenting skills to make that kid stay off FB on the computer vs. homework, or make sure that kid gets out of bed and off to school on time every day and don't have the time to go to parent-teacher conferences, or have regular daily meals together. And then they wake up and try to enforce rules on a 14 year old with a wooden spoon, thinking THAT that will solve the problem. That 14 year old kid will swing back, nearly every time. I see reports every week where it's obvious the parents want the school or the cops to come in and take over the parenting chores.