My case for the strongest evidence RA was involved, all from the PCA:
First, no other males were reported on the trail between 2:13 p.m. and the search.
Second, the timeline:
short version for those who don't want to read my homework: there is a 21 minute period where a witness, the girls, RA and Unsub (if it's somehow not RA) all collide within a 0.3 space and there is no way RA could have NOT seen the girls)
Alrighty, according to the RA PCA we could have one to three cars parked at the old CPS Building -- a smart car, a black Ford Focus and a purple PT Cruiser. The Focus is RAs car and a "vehicle matching the description of his 2016 Ford Focus" passes the Hooiser Harveststore at 6563 W 300 N at 1:27 p.m. and at the old CPS Building at 2:14 p.m.
(The smart car is seen at 2:28, so add that if you believe that's RA's car; and add the purple PT Cruiser at 2:10 if yoy think thats also a terrible case of mistaken identity). The trip from the Hooiser Harveststore to the Old CPS Building is 1 minute by car, so let's say he's there at the latest at 1:30 p.m. (RA says he was on the trail from 1:30 p.m. to 3:30 p.m.)
If he goes straight there, he's likely at the Freedom Bridge at 1:46 p.m. It's an approximately 16 minute walk.
The first group of witnesses see the Unsub at after taking a picture of a bench east of the Freedom Bridge at 1:26 p.m. The walk between the bridges is 13 minutes, but we know the witnesses were going slow because they took a picture at the Monon High Bridge at 12:43 p.m. and the bench at 1:26 p.m. So, not just slow but super slow. That puts them on a collison course with the Unsub. Tracks.
The PCA says witnessess walk across the railroad bridge east of the Freedom Bridge plaza after 1:26 p.m. and before 1:46 p.m. Unlike the other times, the PCA does not say how they know it was 1:46 p.m.
Another witness arrives at 1:46 p.m. at the Mears Farm to the High Bridge. She sees the Unsub on the first platform of the bridge around and she turns around. She sees two girls (presumably Abby and Libby) halfway between the bridge and the Mears Farm parking lot. The walk from Mears Farm parking to the first platform is 6 minutes. So, the run in with the Unsub and then the girls seems like it would be between 1:52 and 2:05.
Libby's video is taken at 2:13 p.m.
Unless someone happened to be behind the girls or parachuted onto the trail like a paratrooper that is a tight window.
Afterwards gets a little murkier. The walk along the road between the far south edge of the Delphi Cemetry by the crime scene to the Old CPS Building is 19 minutes if you follow the highway and 26 minutes if you get back on the trail at the smaller drop off point. A witness sees an Unsub on the road at 3:57 p.m. This witnesses car was caught on camera at the Hooiser Harveststore seconds before. The walk for where CR 300 hits the cemetry and the trailhead near Mears Farm is 7 minutes. That would put the Unsub at the CPS Building at 4:23 p.m. at the latest 4:07 p.m. at the earliest.
In the 2019 press conference, the police ask for info from "between
12 p.m. and 5 p.m." about a "driver of a vehicle they say was parked at the old CPS/DCS Welfare Building in Delphi and
later abandoned on the east side of CR 300N."
Why 12 p.m. and abandoned after 5 p.m. on the East Side of CR 300N (the same side as the CPS Building)? Begs the question of what else LE was told about cars at the CPS building before 1:30 p.m. and what they were talking about re: an abandoned car. I digress.
But ... it sure would make RA the unluckilest man in the world if the Unsub is BG and its not RA.