Given the other agencies working on the case--Latah County Sheriff, Idaho State Police, and the FBI, we are only seeing a small amount of the information. And I'd be utterly shocked if we ever got much info from the FBI. Additionally, there are sealed court documents which may or may not end up being unsealed and released.
I don't think there is going to be a mega bombshell in the remaining documents. I think there will be some more things we don't know, and then a lot of other things that serve to round out the picture on the information that we have.
There's always going to be evidence that doesn't add up to much on its own, but when put in combination with other pieces of evidence creates a fuller picture--whether that's to motive, methods, etc. And some of those things would be things that wouldn't have come in at trial due to the very strict rules of evidence.
AT could try to hand wave away the dna on the sheath, which would require us to believe that it's all just an unfortunate coincidence that BK made a purchase on Amazon several months before the murders of the same type of knife sheath (which, I saw upon glancing through the docs had some identifying number on it--serial, lot?) that had his DNA on it as well as a knife that the ME said was highly consistent with the stab/slicing wounds and yet he somehow no longer has the knife or sheath to prove to LE that the one at the site couldn't be his. But when the other details that show a striking similarity between him and whoever committed the murders are added on to the DNA (having a car that is the same model and color as the one caught on the next door security camera with only a back plate in a region where most cars have 2), having an educational background with studies that provided him with a lot of knowledge on forensic evidence and how to avoid leaving it, etc....then we end up with a level of unluckiness for BK that starts approaching that of Scott Peterson. IMHO.
And when AT is ready to explain to us by what roundabout means BK's touch DNA made it into the tiny grooves of the knife sheath, I'm willing to listen and evaluate that.