Man, I will answer here, but my answer goes to everyone that criticized my post (that had a hint of flamebait to it, really).
I know what I am talking about, I worked for a couple of years in a small town's DA office as an assistant/paralegal and I dealt with battered wives, social workers, the police, the whole she-bang. All there is to it is horrible, I can guarantee you. My wife (as a DA in another town) dealt with it for most of her (15 years long by now) career, and still have to deal with some of it.
Battered wives _must_ be isolated from their abusers quickly, swiftly and irrevocably. If the system does not do that, they go back to him, many times because they think that they don't have marketable skills / enough money to raise the kids or to live, sometimes because religion tells them that they must cope with that, sometimes even because they were conditioned by the abuser to think they deserve to be beaten.
If she made it to the shelter, she calls 911 (999/190), the police gets her kids wherever they are, and they go thru the system. For the night, they don't stay with the abuser. She does not call him. Her lawyer/public defendant/the DA gets the abuser arrested, and the judge will see if it is enough a court order for him to be out of the house.
IN NO CIRCUMSTANCES should abuser and abused exchange words directly. If visitation is granted to him (normally after some time), the victim should arrange for other person (relative, neighbour) to deal with the exchanges of the kids, and should call 911 (etc) at once if the abuser disobeys any terms of custody and/or visitations, because he does not want to go to jail in contempt.
This is women's rights protection 101, and even Brasilian police takes this in a very serious way (especially where there is a vigilant DA), so I have no reason to believe it's not so in other, supposedly more developed countries.