My kid had traumatic experience with the school teacher. He yells and screams at the kids.
I have reported to the school, and as expected, they have not taken any action. What else can I do? My kid is scared and is very anxious about this whole thing. What legal options do I have? What escalation mechanism I have to stop this abusive teacher from hurting other kids?
You can bet dollars to donuts that the teachers/principal knows screaming at kids in a rage is totally unacceptable and will absolutely deny it ever happened. If there was nothing wrong with it, if the average parent believed there was nothing wrong with it, if it wasn't against the law, then they wouldn't lie about never having done it in the first place. They would admit it and say the kid deserved the rage.
Except they know it's wrong, you know it's wrong, we all know it's wrong. If there were cameras with audio in every inch of the school that the public could access then they would 100% stop doing it, because they know it's wrong, that it's shameful behaviour. If parents were in the room they wouldn't do it, because they know it's child abuse.