This probably belongs in a different thread but it is a very interesting theory. Some parts fit: Uncle J just being in the vicinity around the critical time; Uncle J driving past the girls but not stopping to say hi; Uncle J in front of the news camera like a deer in headlights; Uncle J allegedly holding court in an all-night diner after this most tragic event. It also fits in with the idea that OSBI, after knocking themselves out for three months, recognized a drug deal gone bad; but in utter frustration with the P family's lack of information, threw in the towel. If YellowDog's theory is close, then the P's would have had to know who the girls were meeting, and probably who gunned them down.
What doesn't fit is why the P's would allow an 11-year-old girl from a straighter family background to be part of this. Also, the undeniable rage with which this was carried out. This was much more than robbery. Could the P's have been in an earlier deal with the same people, which did not work to the others' satisfaction? Then, this deal was examined after the girls left the bridge and found to be more of the same? So the enraged merchants took off after the kids and used overkill to send their message? Then they took back what the girls were carrying home and slithered back to the underworld?
It also fits with OSBI leaving town without a word to the families (that we know of), or to the community. Maybe they implied that, "If you don't tell us everything, we aren't telling you anything," and to the locals, "Keep your kids away from drugs." Meanwhile, the P's, already overwhelmed by grief, think they are facing more legal problems if they tell all, not to mention retribution from those they told on, and scorn from the community. Didn't they already have to move and lay low once before?
Not a pleasant scenario. No theory justifies what happened and no theory should demean the P's grief. But, as most wonder why the lack of progress and why OSBI has apparently given up, I also wonder if those closest to the victims were 100% cooperative.