I don't mean to suggest that the perp staged the bikes immediately, rather that he grabbed the girls in the woods just before TG came thru (or maybe just after), perhaps stuffed them in a van parked on Maiden Lane, then grabbed the bikes. He had until 3:58 to take the girls to his basement, or pass them off, or what the heck ever, then come back and paddle them to the gate.
Actually, you know what's bothering me? It seems impossible that the bikes sat in one place for several hours without several people noticing. Not necessarily think anything of it, but coming forward after they hear that those two bikes they saw are related to a crime.
I think this because the trail is used more by casual users, like families on outings, kids, fitness walkers, etc., rather than hardcore cyclists and so on. For someone who doesn't plan on going on for miles and miles, they would very likely see the bikes TWICE! From Exchange Park, the trail does not make a full loop of the lake. It circles to the west, then south, then east, but then the trail keeps going away from the lake. To make a loop, one would have to use roads, and go around a little... river? Creek? Canal? To the east of the parking lot (see the maps.) So IMO, any group of kids, families, walkers etc., would most likely go around the lake, then turn around and go back to the parking lot the same way. Even a cyclist on a long looping ride like TG would spot them once. I can't believe that no one other than TG was on that trail in three-plus hours. Those bikes couldn't have just sat on the trailside of the fence unseen for that long... could they?