I think RA went there that day looking for an opportunity to play out a sick fantasy.
It wouldn’t surprise me if he had been there multiple times before looking for the same opportunity.
Nothing I’ve read about the girls’ day indicates to me that the trip to the trails was anything other than a spontaneous idea spawned from teen boredom. They did not appear driven and desperate to go there to meet anybody. I also don’t think RA was monitoring or tipped off that they were going to the trails that day.
RA is a predator. I’m thinking for years he visited different places armed and ready but with no real intent. Playing out part of the fantasy was good enough to give him a thrill. Until it wasn’t enough, on February 13, 2017.