do you physically resemble your father? Are you the age he was when he was so violent?
I've learned to work with dreams and fantasies at face value. You want to be taken away by the police. That's a very reasonable desire for a boy who sees his father assault his mother. Think about It. Are you in anyway like him? What if there were a mental illness that explained your symptoms and his. Could you tolerate having his disorder? Him being as blameless as you?
You are very concerned about your legal rights as a mentally ill person. Children also have very limited legal rights.
Remember, I had a crazy scary preoccupation with controlling a police weapon u.til I recalled a split second of my suburban life when I was poised to jump a cop and do just that...so he didn't shoot my demented father.