But you are still right though. Your reasons were quite good actually, even though when I first read it, I ruled out your reasoning because i thought the girl may tell the cops about her college too and her past, and even Donny might stalked on her. But it turns out, you were right it was Bunny.
About MPTheory and you point out about the boyfriend coming home at night when he should be at work since he works at graveyard shift. I thought well, it said 6 P.M., maybe he started work at 10 P.M. where the shift change at 10:30 P.M. or something. He probably just came to visit her for a few hours then left to work.
But again, the writers purposedly make everyone a suspect too. But to find out the real answers to find out who were the real killer is really over my head. And I didn\'t even thought about adding up the numbers when i read "Add It All Up"...heh.