I need some advice. This is a serious situation. Please help!?

I don't know how to put this into words, but i'll try my best. My mom had this man she was talking to for the past year. She met him off the internet. She basically jump into a relationship not knowing really nothing about this man. She just know of what he tells her. My mom said she was through with him like 2 weeks ago. To me the man seems abusive. Last week an incident happen where he yelling at my mom very aggressively outside. I went outside to see what was up. I'm yelling at him telling him don't be all in my mom face yelling at her. I guess my boyfriend and my uncle heard what was going on, because they came in the front. They telling him don't be yelling at my mom. Then he turned around a cursed at my uncle and my boyfriend and continued to holler at my mom. So my boyfriend and him ended up fighting. The ambulance and police were called. That man was a dirty fighter. He used a staple gun to fight. Now that man is not suppose to come around here no more. That day my mom told him that it was over. Even the police/detective don't want him around here. I had text my mom asking is it really over between them, because he keep calling. She responded back to me saying that it was over between them. He continues to call her and she steady answer his calls. She even met up with him. He even ask for money. He always ask her for money. I want to ask her again is it really over between them. Wednesday i went over to my aunt house crying, because i feel that she with the dude and after all that we went through was a waste of time. when she tells us she through with him, don't let him in the house, and hearing it in her voice that she not happy with him. Even my little brother don't like the man. I feel we all feel she deserve better.