I’ve encountered these sorts of parents before and can tell you they are a fucking nightmare to deal with.

Every indication was they weren’t just advocating for their kids. They were bombarding the school with repeated and vexatious complaints and encouraging others to do the same.

If the repeated contact had gotten to the point that the school felt they needed to report it to the police then thats typically a sign that it was bad. Can 100% guarantee the school would have sought legal advice first.