There are a lot of good ideas here. I look for, "probable cause", You could look it up in American law. There are a lot of websites about this and convert it to Pathfinder.
If there is noise or action in a structure that sounds violent, generally as a rule a GM may allow you to enter. Another example if there is blood going underneath the door a GM may allow you to enter. Look for a reason and that will allow you all to go in and enter a building justly.