I have a thought and I could be wrong but the 3 days that the parents of Brian Laundries said through their attorney that they went on a camping trip with their son Brian, is a lie, JMO
The Laundries parents put their son in that camper and drove him either to the Mexico border or to Canada border, with being gone for 3 days the parents had time to take BL to one of the borders of the US and come home then stage BL scent in the Carlton Reserve Park, again it is just my opinion, if they hid their son for 2 weeks why not take him out of the US, Brian Laundries could walk into Mexico or Canada real easy if he was close to the borders????
I think the Mexican/Canadian is a stretch in this time frame. Entirely too far to travel and remain off any digital radars. Perhaps a more likely approach that allows them to remain off the radar would be a trip to Miami area (or any port city south of their current residence). From there, it wouldn't be a stretch to pay a boater to get him to an island in the Carribean. With a stack of cash, he'd be on his own to get to whatever his final destination would be.
Many of these islands are third world type countries that provide little access to the outside world. If he avoids "touristy" areas, chances are good he could remain undetected in his travels.
With that said, I don't think any of this is what happened. I think there is a reason police are on day 3 in the Reserve. This amount of resources isn't spent with out some reasonable expectation that he (or some item of importance) would be found there. Personally, I think they're looking for an item(s), not necessarily BL. This item(s) would 100%, unequivocally tie BL to the murder. Without this item, I'm not sure the case holds up if they were to pursue murder charges. It wouldn't be hard to convince an honest jury that he did hike on his own in WY. Came back to van and found her missing, searched for some time, and concluded it'd be best to take her van home (not reasonable in my mind, but its a jury that just has to have a shadow of a doubt, not me). Meanwhile, someone else murdered GP.
With the murder weapon (assuming it's an item, not done by hand), they can say, GP was murdered here, with this weapon. BL drove back to FL, and the murder weapon was found in the reserve, that we know BL visited. The case becomes much more 'convictable' in this scenario... hypothetically, of course.