SeriouslySearching, I agree with you 100% about his target being college girls due to their recklessness.
It is pure speculation on my part, and I said it in an earlier post, but I think that the perp is also targeting girls who are out of his league. I think that he is familiar with the area because he is a local, and is able to blend with the people in the area. However I don't think he is a student, possibly never was and he resents the fact that the young women that he is targeting have everything going for them while he is trapped by his own life. He got someone pregnant and is stuck with her and covets the life and the beauty that he has no chance at having....
I could be completely wrong, but that is what I think happened with Edwin Hall. He was a nobody who put on a nice show of being a loving family guy, and chanced upon a beautiful young woman that most likely would never give him the time of day, and took everything that she had that he would never have.