I just don't see anyone - child or adult - choosing to stop at that spot for leisure. I have always felt, though, that if someone had mind to prey upon a trail-user, that spot, right where the inside (lake-side) fence stops, would be the most-likely.
No, there isn't a lot of traffic in this town. Lederman's is in a block-long strip mall, set back off of and separated by Lafayette Ave by a huge parking lot that is also one block long. Lafayette is probably the busiest road in town, passes through what most would call "downtown" Evansdale - although there really isn't such a thing in this particular town. The Collins' live directly behind it, can probably see most of the parking lot from their yard, can see Lafayette from their yard, etc. Lafeyette runs basically E-W on the north edge of town, two busy-ish roads run N-S: River Forest, which terminates at Lafayette and runs along the dike along the river, and Evans, which crosses Lafayette at a spot most would call the center of town and runs south to Gilbert. The police/fire station is on the corner of Gilbert and Evans. The trail crosses Gilbert perhaps half-mile East of the station, and runs roughly parallel to Evans.
I believe he known locally, and has posted on FB confirming he was the tipster. Many locals use this trail daily, for jogging, biking, walking. If you came across bikes at the spot he did, and you were biking, you would remember needing to swerve and also not hit the fence, as like I said, its a blind-corner area, with chain-link on both sides of the trail, which is maybe 8ft wide.
I don't believe he knew the girls. I believe his daughter knew someone in one of the girls' family. This is a very small town, many active locals know and know of each other. Drew Collins (Elizabeth's father) owns a well-known tree service. They are active in the community and in their church, and are well-known.
Incredibly hot. I've lived in Phoenix, and that doesn't compare to this heat we're having. It was 90+ yesterday before 11am, coupled with 30%-40% humidity, making ANY outdoor activity uncomfortable during mid-day. It is 95 right now, stepping out of the AC takes your breath away. Naturally, swimming in that lake is on many non-locals' minds, but like I said, I've simply never seen anyone in the lake, rarely even a boat on it. We have a waterpark very close, another in the next town over, and a free beach nearby. Many, many homes in Evansdale have pools - mostly above-ground. Meyers Lake is used for picnics, some fishing, the park is loved by kids, but the lake itself us mostly just used as a pleasant backdrop to usage of the trail.
It wouldn't be impossible. The water fairly easily accessible from almost anywhere on the lake, save for the backyards of a few houses, and that specific part that is fenced off for trail safety. If you wanted to swim in that lake, that spot is the very last place you'd attempt it, in most peoples' minds. It would require effort, whereas almost anywhere else you could just take a few steps off the trail and be in the water (which is not deep).
He was not a father of the girls, but rather the father of someone who knows the girls that was posting on FB. He also posted, his identity is known, etc, and there was nothing suspicious about it. Rather, it was a helpful, friendly tip (one of very few, tbh).
I just thought it peculiar that the bikes would be found at the most-secluded, least-noticeable from the road spot, in a location that you and I would never think to get off our bikes. Getting the bikes there just to ditch them would also be odd, imo. That is why I was wondering if other kids didn't come across those bikes somewhere else, perhaps farther up the trail (skatepark, closed school, etc) and ride them there as a place to sort of hide while they dug through the bag/purse. After discovering nothing of value, they may have just tossed the bag over the fence, aiming for the lake but it hits a branch or something and falls short. I don't know. That spot where the fence ends at those woods is just scary, and I can't help but think that the girls may have been stopped further up the trail slightly, and their bikes were just moved a few dozen feet out of sight and closer to the water.
The timeframe is the hardest to justify. I think we can be fairly certain of when the bikes were spotted by the passerby, due to him having an accurate record of the time he placed a call shortly thereafter. The grandmother's account of seeing them at 12:15, I hope has been verified. Is it possible she never looked at a clock or never noticed the time, and only came up with that time after the fact? A half-hour either way could make a huge difference.