All I know is that when Rose called the 1st time, Skyla answered her phone.
The girls were shot (per the ME) in the chest and face. That was the original statement - chest and face (later reports said chest and head) and that says they were facing the shooter when the 1st shots were fired. And the media did report originally that be bodies were face down when Peter found them.
Look at it logically - chest shots, face shots - the girls were facing the shooter. How can we be sure they were the 1st shots fired? Why would the killer take the time to turn the bodies face up, shoot them in the chest and face, and then turn them back over face down AFTER shooting them in the back of the head? A head shot and there would have been no question they were dead and no risk of his DNA on the bodies.
The only way this could go down IMO, is the killer(s) approached or drove up alongside the girls and blocked them into the ditch/brush They turned to face him, the 1st shots were to the face and chest (the girls facing the shooter) - chest shots 1st and the girls would have bent forward instinctively clutching the wounds and they would have fallen face down - and if the killer did shoot them in the back of the head or under the chin, those shots were done AFTER the other shots to the chest and face. The killer(s) used TWO guns on each girl, meaning he/they emptied at least one - that's 5 or 6 shots while facing the killer, then (according to witnesses) there was a short break and then a second gun was used - maybe 2 or 4 shots from that gun. Timing wise I think the second gun was the one used for the head shot(s) after the girls were already down.
Either way, the shooter(s) would never have to touch the girls - even an under chin shot can be done with the body lying face down, if you are willing to kneel down and get very close to the body. But I will be interested to hear if there were shots under the chins of both girls - all we know about now is the one supposed under-chin shot reported by Skyla's GMa Claudia. if only Skyla had a wound under the chin, it might have been a shot to the head/face/neck that caused that wound. GMa was not a bullet wound expert and exit wounds sometimes look like entrance wounds. Since we do not have the full autopsy report, we just don't know at this time.
My Opinion