Members are wondering what might have caused some alarm for the girls.
My theory is they passed him on the trail, or he was on the adjacent trail where it splits off from the trailhead, up close to C.R. 300. So they saw him.I've also considered the time of year, plenty of visibility through woods which during the warmer months would be overgrown.
Then BG proceeds to head back towards the bridge, making sure nobody was behind him. So I picture him repeatedly looking back towards the bend in the trail, back towards the parking area and trailhead, as he's walking towards the bridge. They may not have noticed that yes, indeed, he's the same guy they'd seen say 20-25 minutes earlier until he was on the far end of the bridge (relative to where they were).
I can picture what objects at 600 feet looks like from a distance, hard to make out familiar people and whatnot. The bridge is 850 feet long. I'd imagine A&L were somewhere between 600-700 feet along on the bridge when he got on it. It would take roughly 4 or so minutes to cross it, being mindful of the bad condition of the bridge (stepping over missing sections, etc.).
If they'd already passed him, why would he be heading back towards the bridge? Last I checked the bridge (not the trail) is still CSX property, in fact people are not supposed to be on it, but at any rate technically the trail ends at the bridge. On the other side is private property. It appears that a lot of folks walk to the bridge and then turn around.
Locals would know much of what is around the bridge is private property, and maybe some folks who have poked around maps which are available online.
I think anybody familiar with the bridge and trail would be suspicious of someone they'd seen earlier on the trail, later get on the bridge to walk all the way across. Not half-way, not 1/4 of the way. All the way across. Besides. what is on the other side? Private property. My hunch is BG was waiting for A) Someone to walk the entire length of the bridge, and B) For there to be no one behind him on the trail.
MOO is he was there for roughly 3 hours, waiting for his prey.
(Edit)
Why would this grown adult be out there that day, just snooping around, and later gets on the bridge to walk the entire length of it? There's just a private driveway to a house on the other side. Where was he going? We all know the answer, and I think A&L knew something was up when he didn't turn around on the bridge.
The private drive leads slightly up hill and around a bend to a nice property. The owner happened to be in Florida when this happened. Going the other way, the private drive becomes C.R. 625.
The guy seemed suspicious, so Libby had the presence of mind to record him.
MOO