Thanks to your GF for following them you can make these guys pay for what they done. Had she just let the cops pursue them to start with after the first call to the police, I doubt they would have found these guys. But she continued to follow them and calling the Norton Police so she let them know they were not going to get away with it. My opinion these guys have done this before and probably worse, this time they got caught. So you owe your GF and she should get whatever she wants now.