Usually where there is domestic violence there is a victim and a perpetrator. Often the victim believes that they “deserve” the abuse they receive.
If there are children, the perpetrator will often threaten to kill the children if the victim tries to leave. Sometimes the violence escalates to murder.
In your situation Whale, if there is a victim, that person probably believes that the police are powerless seeing they have attended, yet the abuse continues.
There are Refuges and services for victims, but usually they need someone to tell them they do not have to put up with the abuse and direct them to some options. Social Workers at hospitals or Community Centres can help with advice. The front of a telephone directory gives Community organisations.
Once the victim is safe, then you seem to have enough evidence of damage, etc. to continue to remove the perpetrator.