I re-read your account and what I now see is that this was not one incident but a SUSTAINED PATTERN.
You should write it down, sign and date it, and get the same thing from the parents of the goyish girl.
Don’t fool yourself —the school simply does not want the name of the school in a police report, and if you kept mum they would be relieved, sure, but they would NOT see themselves as, “owing you one”.
They would owe you one only if you DID call the cops.
Before calling the cops, document clearly and concisely what happened to your daughter with as much detail as possible. Sign and date.
ASK the parents of the other girl to do likewise. Sign and date.
Then call cops, be super polite, and present your docs. Don’t give long answers. Don’t speculate. They’ll ask you variations of the same basic questions to verify that the underlying facts are not tailored over time.
I think calling the FBI is way over the top.
When I had to do this, I was surprised at how effective it was —the muzzie was arrested the next day (in San Fracisco, of all places).
I rushed down to the station to ID the guy on Saturday at 6 am, no less. He’d been terrorizing that part of the city, and no one bothered to write stuff down and report it.
He got sent away. He’d been doing that stuff for a LONG time.
I had NO experience at all getting folks arrested, complaining, or making police reports. I still don’t consider myself a complainer, but the experience made me mightily impressed how important written docs are for bureaucrats like cops.