He’s a psychopath

I believe my brother is a psychopath and so does my mom. All the things he’s done in his 15 years are so disturbing. My dad disagrees and thinks that he’s just a little angry sometimes.

I want him to see someone. Like a doctor or be locked up in a mental hospital. He has verbally and physically abused since he was 9 and I was 10 and he does the same to my mom. I have always been scared of him. Yesterday he pranked his friend who is 2 years younger by choking him and pushing him on the bed saying that he better not piss him of again and he started laughing while his friend was on the edge of crying.

He needs help. My dad has full custody of him and therefore he is the only one that can do something. But he doesn’t think that there’s a problem with him. When I start school in 2 weeks I want to talk to a teacher and see if they can help. But is there something I can do in the meantime? I honestly don’t care if they lock him up and I never get to see him again I just want him out of my life and everyone else’s.

Please help me