What if the location, CB, was only slightly know by the supects, (ie. noticed for sale or vacant while in CB on other business)? Then, more recently, scouted by boat to see if there was access between the driveway and river? Maybe while out for a "fishing trip" (that really had nothing to do with fishing, but just putting together the final preparation on a planned murder)?
Since the trail was only recently made - someone must have arrived more recently to put the finishing touches on this plan.
Also, since this is a new trail, my assumption that this must have been someone with a past connection to this property no longer holds up. Unless there has always been at least some sort of trail down to waters edge? Del Rio???
No one would want to be searching for a trail in the dark with a body, especially if they didn't even know if a trail existed!