[user104658]

They were already banned from entering the school including attending parents evenings and school shows... I'm not saying it's impossible that there was a massive over-stretch here (god knows, I've encountered some absolute arsehole teachers and headteachers) BUT I feel there is probably more to this story than is being reported, honestly. If it was just that they had suddenly had police turn up after this complaint that would be ringing massive alarm bells but the fact that they were already straight up banned from school grounds even on perant's evening... something has gone down in the past, would be my guess.