A few observations re: tire tracks:
1. I've driven on a fair number of dirt country roads. The speed limit is usually about 30mph or less because the roads can be uneven and many have a "washboard" surface. If you lose traction, you can lose control fairly easily. On these roads, there is often one set of tire tracks that everyone sort of drives in. More or less, you drive the road like it's a one way until you see a car coming, then you move over. I can see this being done in a dirt driveway--every car could line up to drive through the same "channels"/tire tracks, so to speak. Often, the dirt outside of these main tire tracks is very soft, and would easily show footprints.
2. The dirt in the DR driveway doesn't look quite as "deep" as the country roads I'm thinking about. The photos don't really show that "one" set of tire tracks. But it does seem like the more cars go up and down a driveway like this, the more compacted the dirt becomes and it gets more difficult to see any distinct tracks. I guess my point here is that it seems like it truly could go either way--maybe DR's stories about the cars coming in and out that day is a lie, or maybe the dirt shows only the latest/most fresh set of tire tracks. If the perp was walking in the well-driven area, with Jacob off to the side, it makes sense that Jacob's prints would be more visible, as the dirt toward the side of the road would be deeper and more impressionable. Of course, lots of "ifs" and "maybes" here. I just don't know.
3. If a car had driven through the ditch and any part of the grass/woods adjacent to DR property, I really believe there should have been a good chance of that car leaving some tracks in the grass. The weight of the car, especially if it had been sitting there a little while, would have crushed and/or made some path through the grass. This is ditch grass--it's longer and more wild than an average lawn. You can kind of see this happening in the photos of the bikes--upon removing the bikes from that area, it would still be clear that something had been there. And yet, it all depends on the type of vehicle--a compact car would be lighter, but it would also be lower to the ground than a truck, and therefore more likely to mow down a little bit of grass when off-roading.
It's just hard to know how much to make of the tire tracks.
Re: Wisdom's Theory of Practical Joke Gone Wrong
I like this theory. Being home alone, DR might have even seen the flashlights and thought people were messing around or causing damage to his property. For whatever reason, he decides to go out there to scare or confront them. Maybe he thought they were teenagers, or at least a little bit older than the boys, and wanted to deter them without getting the police involved. Might he have asked their ages because he was surprised they were just kids? But then what? And why Jacob?
He might have kept one boy and then sort of staged the idea that a car was responsible, therefore buying himself some time to figure out what to do next. This deflects attention from him and away from his property. If he had let all three boys run away, it's more likely that LE will focus on him and on his property. There'd be no reason for someone to flee the scene. And we know from the timeline that others have worked on that there was quite a bit of time at DR's disposal. But where is Jacob?
I'm sure LE has looked into this, but is there a chance there's an old well, or storm shelter/tornado shelter, or another kind of underground bunker so to speak on the DR property? Maybe something only the property owners would know about?
Wasn't there a photograph of DR where there's a nylon stocking hanging on a hook in the background? Not the most foolproof evidence, but still.......................