I want to say again, this is horrific. There are at least two problems here.
One is systemic: systemic racism, a terrible carceral system, and not enough support within education. I wouldn't be surprised if poverty played a role here too; thanks, redlining, for all your help with that.
The second is personal: it sounds like this asshole was cruel, angry, and abusive. He should never be put into a position where these traits could be taken out on the vulnerable.
My frustration with the reflexive response have nothing to do with not acknowledging any of these factors. I'm glad he got fired and I hope he gets punished.