Okay, Devil's advocate time: I don't know all of the facts, but I can understand why they might have called police officers to deal with the situation (Though this relies on a ton of assumptions so don't take it as gospel.)
If a ten year old autistic boy is causing problems and becomes violent, he needs to be restrained for both his safety and that of those around him. Now ideally the educators employed as part of the school's "Special Education" department should be trained for this kind of thing, but given how inconsistent funding for schools can be even in the same state, you can be left with teachers who perhaps aren't comfortable restraining an autistic child throwing a tantrum, and perhaps the school itself fears a lawsuit should the boy become injured. So from a certain perspective, it makes sense to call the police in.
Struggling to see how this justifies arresting and imprisoning him of course...But the fact that the police were involved isn't in itself a problem.
You don't call cops to deal with a ten year old kid throwing a tantrum. You call the parents.
Jesus, what is wrong with people?