Unless I have missed something, nobody seems to be denying that HD's scent was at the Western Suites. Whether it was old, new, she was in a car, walking, picked up willingly, kidnapped, or someone had her clothes on their person, the scent was found there. They need to find the link to the hotel. Why is a 13 y/o at a local hotel? Or who was staying or parked there that had her scent with them?
If she was meeting a male (any age) that day or any day, her closest friends knew. If they know, they need to come forward. If the friends truly don't know, HD was caught off guard whether by someone known to her or a stranger.
I don't know how the dogs work, but could the dogs be taken back to the spot they smelled HD and told to pick up on another scent and follow it?