Legal Question in Family Law in Missouri

Re: i want to leave my abusive boyfriend & take kids but have no proof of the abuse.

I am sorry to hear of your situation. Your post did not include enough facts for me to be of much help. You refer to your "boyfriend" and "the children". I assume that you have children with a man you refer to as your "boyfriend". Has he ever been determined to be the legal father by a Court of Law? Or, has he adopted the children legally? If not, it is likely that he has no legal rights over the children whatsoever. Even if the State division of Family Services has declared him the father for child support purposes, this would not give him any rights regarding the children. In the first place, I would separate from him and obtain a protective order from the Court covering both yourself and the children. Then, if you choose to relocate with the children out of state, I believe you would be free to do so, and in the meantime you would have some legal protection from the abuse. Good luck.