Hi,
Subsequent posters quoted the article in which the mother made the comment that Shannon was pulled into a truck - my take from reading that was that she was continually on the phone and it sounded like she was pulled into a vehicle, and that the police arrived shortly after that but she was gone. But that is the only place I read that (which doesn't mean it isn't true of course) - I brought it up because I wondered how much of the 21 or 23 minute phone call, whichever it was, was made outside of the john's house. That is pertinent because they make it sound otherwise like the entire phone call was in the house, which is curious, but that might not be true.
You missed my point about the possibility of the circumstances of the john killing her. I was throwing out the possibility that (hypothetically looking at him as the killer) he never intended to harm her that night (because obviously he could be tied to that)- but that something went down in his house that threatened HIM (as in, revealed what he had been doing) and necessitated him taking the chance of going after her. I would think that anyone killing prostitutes would make sure they were at their most vulnerable and not going to be missed when they did it, which is why I would find it unusual that he would hire her to come to his house and then want to kill her. But a SK of prostitutes may frequent them regardless, and it may have been his intention just to have a "date" with her that night. She may have somehow come across something that revealed what he'd been doing- who knows? or done something that crossed a line or, as I suggested before, drugged her. Once she sounded the alarm, he couldn't just let her go, and since it was still dark, secluded and no police were in sight yet, he still had the opportunity to get her. It's just an idea, and I think it's plausible.
Desperate people do desperate things, so if it was super important to whoever killed her to get her and silence her (before the police could get whatever info. she had) it wouldn't be unlikely for that person to take some chances - and SK are pretty bold to begin with.
It's horrible to be hurling accusations at people who may be innocent, but I'm just speculating, because the circumstances are just very strange. But there is one thing I would absolutely bet money on- there is a connection between Shannon and the murdered women. There is no way on earth that is a coincidence. That's what I believe, and since it's a logical starting point anyway, I think it is valuable to exhaust all possibilities of what the possible connection could be before looking elsewhere.