A very good point that should be considered, "think outside the box".
Why was the POI truck side ways and the tail gate down on his truck? to get the girls out?
Moving the girls from the actual location where they were murdered, in order to throw LE off from the actual murder site, and who, and why
Possibly putting the girls beside the road.
It wouldn't take a rocket scientist to throw down a dozen "shell casings" near the girls, anyone that uses a gun would know to throw down the shell casings.
Did the POI slip-up and throw down the wrong amount of casings?
Why did LE bring the dogs out, after the road graded over all the evidence, looking for more casings?....imo, because there was MORE shots in the girls than casings found..