Chris Brown

What do I do when my brother hits me and is very violent towards me.?

So I’m 18 and my brother is 14 my brother hits me and is extremely aggressive to the point I have bruises. He has 4 pocket knives and he sharpens pieces of bamboo to where they can cause seriously injury towards someone. He thinks about killing and he has stabbed someone with scissors in the hand. He also backhands other kids at school and hurts them. I tell my parents and they tell him to stop nothing else. The school told my parents and all they did was constricted his computer time. My parents refuse to go to family counseling and they make excuses. So what do I do?