You only have 2 options:
A) Avoid a bad situation. This is family. You decide when it's worth being around or not.
B) Realize you can't change or fix this. The only good you can inject in the situation is behaving the way you believe is right/moral/justified and let the chips fall where they may.
You going to jail changes nothing and only hurts your life and family and future.
You'll be in a cage and he'll be there with your mother...