Trunks dear, this is a terrible thing. But listen to others' suggestions: they said better than I could what you should do. Don't let your girlfriend feel lonely in this occasion, let her stay with you if she can, let her feel loved and let her see you're truly willing to take care of her, to help in her recovering process. The trauma in this cases is terrible. For this reason I think you must talk a lot to her, try to know better her feelings about this without making her feel under pressure. Talking can be painful at first, but it's a good way to release all your anger and fear, so make her talk about this if she wants, make her feel reassured and safe with all your deepest affection and interest. Trying to find these criminals alone won't help her, or at least being her I'd be even more stressed and afraid for your own safety, so I would end feeling even more worried and terrified. If you can and if she agrees, to act against them without the risk of finding yourself in trouble, report this incident to authorities. But I repeat, most of all stay closer to your loved one to make her feel she can count on somebody and she doesn't have to face this all alone.
Good luck for anything
