I question his motives, too. Sorry, but it seems extremely unhealthy to look at a girl who has been so badly traumatized and say to yourself "ooh, I'd like to have some of that for myself". The most helpful people are the ones who remain objective, not the ones who interject their own emotional issues.
This girl needs help - not romance. If this story is true, do her a favor and REALLY help her by calling the cops, or at least call the rape crisis hotline for further guidance. Your romantic interest is a poor excuse to not do the right thing, and she is a child, after all.