Ok, this is MOO only but gathered from many puzzle pieces along the way thanks to everyone that posted anything on this case. Yes, so much repetition and rehashing but it all matters - it all swirls around until it starts to click and every contribution is part of the puzzle. I admittedly still have some missing or unclear pieces and I COULD BE 1000% WRONG but...
It is JMO that RL was not home when the girls were killed and he had NO knowledge of the crime at that time. I believe he may have been less than truthful with his alibi later due to his probation and that is what they finally used to land him in the pokey. I don't believe LE thinks RL is the primary suspect but I think they feel sure RL knows who is (as do they). I believe in MOO that RL may have found out as early as sometime after the first search for what was then "missing girls" was completed and called off for the night. I think it turned out that BG is very well-known to RL which compelled RL to then begin assisting BG so that BG would not be discovered. It is possible that he still did not quite find out until a few days later but at some point RL became aware. I do not think RL was directly involved in killing A&L in any way.
I am reminded here of the tagline of Netflix' show Bloodline: "We are not bad people, but we did a bad thing". I think this is applies very much to RL and his involvement IMO. As an aside, I am still feeling sad for his happy, little dog.
MOO I think it is possible the girls' bodies were moved from or through RL's property (or from the grain bin through RL's property) down to where they were ultimately found but that the intention was possibly to get them in the water to destroy evidence at the very least and to possibly make it seem they had fallen from the bridge or had some other accident. (Remember, we do not know COD and LE seemed uncertain of the scene upon the discovery - I don't have time now to find links so MOO this but I think this is pretty well stipulated info at this point.) Also, how many of us have wondered why would a killer leave the bodies on his own property? I don't think that was the plan at all but there was some reason they didn't make it off the property and into the water. I am NOT saying RL is the killer here, just a general "no one in their right mind would want this on their own property" kind of thing.
It is JMO that Libby's phone likely did ping or otherwise appear to be located on Bicycle Bridge Road (in Delphi) but may have been in a vehicle parked on BBR which caused the SW to be for the wrong house. I think it may have been balled up in other crime scene evidence in the vehicle or something but I do not think it was in Libby's possession at this time. I really am not settled on whether LE has the actual phone or not but I feel certain that data from attempting to locate it is what lead to BBR either way. I am skeptical of it being cell phone tower pinging and think it is more likely it was phone device tracking done by a member of Libby's family and/or LE. It must have been something reliable enough to get the SW at any rate IMO. I believe BBR is a key component in this case if you are so inclined to research it further.
MOO but I suspect LE's mention of "blind alleys needing to be closed" (not a direct quote) would include things like RSOs and drifter types at this point. I think they threw everything at this case in the early days to cover all the bases (billboards, national coverage, etc) and rightfully, thankfully so. I think the picture began to reveal itself to LE once they were able to get their bearings on the case and get people interviewed and alibis checked and so on.
Lastly, it is MOO that this case is on it's way to resolution and I hope the arrest goes smoothly and there are no standoffs or anything. I think BG must know they are about to nab their guy. MOO
The above is my opinion only.