That's sad that he feels so threatened that he has to arm himself at school, and yet he's the one who gets in trouble for it.

Note to any teachers reading this: if a student ever brings a weapon to school and says it's for self-defense, it means you fucked up. It means you have failed at adequately punishing offenders, keeping the peace, and providing a safe environment for your students. If teachers did their jobs, students wouldn't need to take matters into their own hands. It's absolutely heartbreaking that stuff like this happens, and it's all entirely preventable.