Now this may be totally out of left field but I've been thinking about this theory a bit. What if DS did this to make a point and not only get back at CD (if he was in fact infatuated with her) but to "show" his parents/family? He used a company/family associated vehicle and Hailey was found on family property. What if DS parent were angry and upset with his pending charges and made some sort of comment about how "Terry turned his life around, why can't you?" Or something along those lines? It was well known around town that DS and TB didn't get along, maybe that could have triggered a "I'll show them" mentality. It doesn't explain why he would take Hailey's life, but he may have assumed that TB had already taken her up to CD and not expected her to be there. Just a thought I've been having. If DS isn't thinking clear because of drug use or a mental illness that could have been a good enough reason in his mind. I'm still not sure that I completely believe this either, but I do think that it had something to do with it.