I have no idea what RA thinks or why he does things and I wish we could all understand these types better because maybe we could prevent some of the evil things that occur in the world.
I personally theorize that he didn't didn't realize the bullet could be traced to his gun just from being in it. He didn't fire it and he didn't know he was recorded and the girls are heard saying something about a gun. So I just think it's as simple as he had no idea the gun would link him to anything. Maybe he likes that gun and he's used it before (I wonder what this other bullet in evidence is from??)
I think it's possible someone that commits this type of murder also likes to keep things for whatever reason they have.. fetish, souvenir, something else??
I hope we hear more about all of it at trial because I really am curious. If others are involved, I wish RA would say that. I just can't believe he had zero to do with this and I do think that video Libby took shows him and there is no other possibility if BG on video is RA, then he either had a gun and told them down the hill or he saw and knows who did do that because 43 seconds of video is not enough time to have him in the video and then he just walks away and some other guy arrives and RA is oblivious and sees nothing (what he told DD about that day.. didn't see Abby or Libby).