I've moved on from trying to map her run route. I think that she was take at an isolated part of the route - somewhere near the cut-through to Moms. There's a lot of isolated gravel roads in the area off Rt 385; an isolated route out of town with low traffic. What happened after she was taken?
First off, I think the perp gets down to the main business at hand - why the abduction in the first place? Even if the phone and fit bit are active, he has a goal. I don't have an answer for this, just yet.
If the need is quick-and-to-the-point with seclusion, one could go Rt 385 to a right on 185 down a dirt road that dead ends at Little Bear Creek. I think she may have been put in the water here, or a site like this. I think LE knows this, but haven't found her (and is holding this info back).
After this, he goes on an evidence dump. Back up 185 to Rt 385, then left to v21. Left on v21 to the bridge at Big Bear Creek, where he dumps the phone.
The next part, going so far South on v21 to dump other evidence (fit bit?) I'm not sure about unless he knew in advance about WC. All these back roads, on grave surfaces, to me indicates some sort of pick-up truck and knowledge of these roads as being an avid hunter.
I think it might be someone that both DJ (his age) and MT went to HS with, and had a crush on MT. He didn't go off to college, and stayed local working in Brooklyn. He supplements via B&E or drug distribution. I think he knows how digital footprints work. Maybe Mollie was just in the wrong place at the wrong time.
So much for my novel. As a father of kids this age, it pained me to type each and every sentence of the above. I'm admitting defeat, as in she's not coming back alive. I deeply sympathies with RT and his stoic interview hoping she would be OK. After 4 weeks I only want closure for the family.