For RA descended from out of nowhere to be innocent, he would have had to leave by an unknown route in that brief span between BB's absolute timestamp, fitbit confirmed, when she saw RA on the platform (right where he said he was) and Abby and Libby's appearance on the trail, also timestamped by BB.
Then someone just like him but also somewhere, in order to follow the girls across the bridge.
The Defense tried, with no success, to move the time of death far, far from 2:30 in an attempt to distance the crime from RA, on the bridge.
So that is really the pivotal fact in this case IMO.
If one believes Libby's video and cellphone data, that the phone's movement stopped at 2:32, signaling the final movements of both girls, then they didn't die later that day, didn't get in a car, didn't plug any earphones in, didn't go somewhere else and come back. If we JUST use the cellphone data for movement to try to piece together the girls final movements, IMO it's chilling, it's compelling and it's complete. There's no point in developing fanciful narratives because what is simple, horrible and entirely reasonable is that
they were abducted at 2:13 by a lone man who followed them, trapped them, forced them down the hill, where he firced them to undress. We will never know what he may have made them do, see... but Libby's phone DOES record the moment they were kidnapped, DOES she that Libby was actively stepping until 2:08 after which almost no movement for her, including dropping below the bridge as ordered. No real movement until 20:18, consistent with the the period of SA (young teens forced to strip maked IS SA).
Then a flurry of movement which is consistent with crossing a river and consistent with the location at which their bodies were discovered.
We don't know who had the phone but we know it crossed the river. We can infer the river crossing wasn't altogether smooth (based on clothes that were abandoned there), we do know Abby must have redressed before crossing the river iirc, and we can imagine (as much as we surely don't want to) that the girls were being told what to do, perhaps he ordered them to re-dress before moving to the more secluded location but it wasn't happening fast enough, panicked, not understanding that switching the clothes left one girl without clothes to fit into, if he was ordering both to re-dress. Or they thought he was going to let one of them go so Libby passed her clothes (and the phone) bravely, smartly.
Minutes after crossing the creek, both girls are bleeding out....
Unless one believes the girls somehow left. Without the phone. And came back later to die on top of it. Is there a white of proof to support that? Beyond it being WILDLY incredible. In the history of EVER, has a kidnapper successfully kidnapped a victim, cleared the area, brought them elsewhere, then returned them to the heart of the crime scene, the exact location from which they'd first done been kidnapped? And then been murdered????? THERE????? A kidnapper who brings his victims right back to their phone? In the most likely place searchers will already be searching?
Or a middle aged creep, with some daytime beer in his system, kidnapped two little girls only to realize he had no idea how to handle and orchestrate it, in a public setting no less. Panicked, devolved into chaos -- total disorganization -- culminating in brutal injuries from a quiet boxcutter?
It's disgusting but it's not a mystery.
JMO