It is a very difficult circumstance to be in, and not as clear cut as you seem to think. It is perhaps something you can only understand if you have gone through it yourself.
Of course. It is definitely one of those things i can sit here and say how i would do things but until in that situation i don't know especially with different circumstances.

My parents had shared custody of me and my younger sister but with what happened with my sister there was no way he was getting anywhere near us.