IMO, I think it's possible they really don't have DNA or other digital or physical evidence (except the unspent round) linking RA to the CS or the girls, but it seems they are banking on the evidence proving RA is BG (the abductor). With the video recording of the actual abduction (great work L!), the case might truly be about witnesses, videos, and RA placing himself on the trails at the right time, in the right clothing. Even the unspent round probably isn't needed under the felony murder charge, although it would be extremely helpful in linking RA to the gun used in the abduction and/or the CS. If the jurors believe it's his, that places him on the scene. If they don't, then do they believe the witness and video evidence placing him there? Either way, the unspent round holds much more significance to the kidnapping than the deaths, since they did not die by gun. All of this helps the charges make sense, IMO.
Even the theory of an accomplice, which they have never outright dismissed since NMcL claimed such in court back in Nov. 2022, would make Murder One harder to argue. JMO.
I guess I do sit back and consider the charges and what that might possibly mean for what LE has for evidence. However, I don't think that has to mean they have a weak case. We know very little of their case against RA, honestly. Perhaps they have a strong one against RA being BG. But then what are the families supposed to think? That their children's killer has been served? Or will they, too, always wonder if anyone else was there that day? I hope NMcL makes this clear at trial. Otherwise, that book will always be open to the same page. JMO.