There is a person in your building, you are pretty sure that their partner is hitting them. They stay to themselves and wear clothes inappropriate for the hot summer weather. You have tried to talk to them but they back away. Do you call the police?
Unless you have information about the aggressor and are specific with the police concerning who is the aggressor and who is the victim. This is not a good idea. Often the victim is unintentionally arrested. Aggressors are very convincing good at the con. I was once arrested when my neighbor called the police. My ex convinced the police that I started it by spitting on him. The neighbor later apologized she thought they were going to arrest him, she knew I had been looking for my chance.
This is what she told the police: They are at it again giving our names and address.
What she should have said is He is at it again, he blah blah blah. If she had done that, the police would have gone into the situation with the thought that he is the aggressor. Things would have been different.
Many times the escape is just as dangerous as staying. My freedom day came the day my ex tried to run me over. The neighbor called and said He has the kids in the car while he is trying to back over their mom. I had pushed my ex into the bathroom and shut the door on him. I had secretly packed a bag leaving it by the door. While he was trying to get out of the bathroom, I threw the kids in the car. My mistake was worrying about putting them in their car seats before I left. He pulled me out and I was not going to allow him to take my babies for his abusive pleasure. So I opened the hatch and tried crawling into the car. That is when he started to back up. When the police blocked him in on both sides, I was hanging on for dear life.
I should have just jumped in the car and drove down the street and then gotten them in their car seats. However, the main point is calling authorities must be done with caution. I know of too many women that were forced to leave their children with an abusive husband because he convinced the officers that she was the aggressor. It does happen, men are victims of domestic violence. She can be like me and be covered with bruises, but she may also be like me and fight back. I fought back because I was determined he was not going to hurt my children. Yet the emotional scars of watching all that are still with my children. My children who had a wonderful man adopt them. My children who I got away from that crap. My children after 25 years, still have emotional scars.