In my area (northwestern Ontario), the police arrest the person who does not have any wounds in a domestic dispute, so it is best to escape and call them, rather than fight back and call them.
I am just finishing a case in which my client was charged for assaulting her husband. She is a petite and demure church secretary. He is a big athletic fellow who suffers from a frontal lobe injury that causes him to have poor reasoning ability, significant anger management problems and extremely poor impulse control. She says he slammed her from behind into a refridgerator and she pushed out from under him to escape and call the police. He says he was walking past the refridgerator when she spacked him. There was a slightly red area on his cheek when the police arrived, so she was arrested.
I was speaking on Thursday with a womanwho has been separated from her cusband for over two years, and who’s husband has been in and out of psychiatriac institutions for years due to his repeatedly being deemed to be a danger to himself or others. He was let out recently, and showed up at her house, where he grabbed her. She fought him off by biting his hand, fleeing, and calling the police, who arrested her for assault. While she was in custody, he returned to the house and broke all the ground floor windows, leaving a fair bit of his blood on the broken glass. I expect that hee too will be arrested.
Bottom line? Where I live, women must take care no to leave marks when they defend themselves, for the policy of the police is to arrest and let the court decide if the contact was in defence or not. I find this astoundingly stupid, and have said to so to several arresting officers. I think that in such circumstances they should arrest both parties when both parties are claiming that the other assulted him or her.