I agree, I would get a therapist involved asap. My concern is the repeated incidents with the school. He’s brought weapons twice and probably will again as he enjoys the reaction. I worry that when that excitement dulls he could escalate and someone would get hurt.

Does he have a therapist or psychologist? Honestly, I would consult some one. I feel like a lot of teenage boys seek danger, fast driving, doing generally stupid stuff but it wouldn't hurt to talk to someone about it because you don't want it to get out of hand.

I don't how it works in the UK but here the possibility of violence especially with potential weapons in schools is a serious issue. Does he want to be expelled from school? Bullying younger kids isn't a good sign. Maybe he could channel his negative thoughts into writing. My nephew wasn't violent but he was into drugs and theft. He's spent years in prison and is still there. It all started with little things and he didn't take his punishment seriously.

Is he watching YouTube influencers?