[Satine]

My guess is that since he is being hit like this, his best bet is to report it to the police. Whether they actively help or not he is producing something called a paper trail. This means that if his father hits him again, there will already be evidence that it has happened before.

This is a good way to prove that he needs support from the state.

I don't know what support services are in his area but if he asks the police then they should be able to direct him to somewhere he can get more help. It is worth him looking for financial help, housing and any kind of personal support he can get.

Is his disability something that requires extra help? If so, what extra? I suggest he looks for help with that too.

It is important that no matter where he is - living with his father or living somewhere else - that he has friends to stay in touch with. You, for now at least, are part of that support. He will certainly need more contact with people so if you can encourage him to meet people then that will also help him feel happier and stronger.

Good luck, to both of you.