Hate begets hate and all that follows which unfortunately can include people getting drunk and waving guns or knives around. Labeling people can sometimes result in a person becoming what you label them. Insulting people can create the insult. It's how the mind works. Perhaps he read the comments from the last article regarding the school, got drunk and went to extreme with his mind full of insults to his people and family. Who knows? At least they have him in custody for now and he isn't posing a threat to anyone currently. 
Entire point being, the hate needs to stop before anything can get better! Otherwise it will only get worse.