[Rick Lee]

I believe the police can enter the house, since the wife/gf probably gave them permission to do so and certainly constituted probable cause for a search. They could have knocked on the front door, kicked it in or walked around the back. Even if the woman wasn't bleeding, it's pretty understandable they'd want to have a word with the accused, maybe see if his knuckles were red or he was intox. And plenty of states have must-arrest laws, whereby if one party calls the cops for a domestic abuse situation, someone WILL go to jail. they have to arrest someone. I hear such calls are just about the most danerous cops ever get. That and dodging cars on the side of the road while talking to someone they just pulled over.