You say it's isolated, no witness. I believe you
I still think the few statements regarding the number of perps, familiarity with the homes and the children are meaningful. After these statements I would find odd if investigators were clueless. Especially after 5 months
Investigators must know something about this case for blocking custodies, autopsy reports and having a gag order.
If it's not about a potential suspect, it is at least about the nature of the crime or its motivation.
I'm beginning to think it's about someone local (not necessarily close family) who knows something about what CR1, et al might have been involved in to cause the murders. This person may not have been involved nor had foreknowledge of the murders, but once they happened, may know who was behind it. This person may be so frightened, they're afraid to talk.
One of the links above about cancelling the family reunion had quotes from Tony R that I found interesting. He noted that when the erroneous story about arrests at the Texas border being linked to the case were reported, his family called to see if it was true. They waited and were disappointed to hear it wasn't. To me, that means they don't know the killers either. My impression only, is that none of those other Rhoden family members had much, if any knowledge about the criminal activities of CR1, GR, KR, etc. They seem as much in the dark as anyone.
If LE is waiting for anyone to crack, it's likely some locals involved in the same business/criminal trade, who weren't involved but might know or suspect who was behind it. In that case, you would think LE would approach them, ask for their cooperation and offer them some kind of witness protection/relocation, etc. in exchange for their help. If that's the case it could be one or two scenarios:
1. LE has approached other locals who may have knowledge offering a deal and protection, but they don't feel like they will have adequate protection. Perhaps they fear insiders in LE may leak their whereabouts to the killers.
2. LE hasn't approached other locals who may know something because they don't want their help.
3. This, IMO, is a less likely scenario. Other locals may include undercover agents/informants who are trying to find out who was behind he killings and retrieve some sort of evidence. Haven't acted yet, and don't know who was behind it. This seems less likely because, in the drug trade (not just MJ, but possibly harder drugs) it seems reasonable they already know who the major drug players are. They've been watching (and sometimes busting) them for years.
In none of these cases does it make sense to seal the autopsy reports unless the killers or persons behind the killer left some kind of signature "calling card", etc.
Like this, sometimes called narco-messages:
http://articles.latimes.com/2008/jun/11/world/fg-message11
It could have been some sort of message left behind that would have to be included in the autopsy report. A message to LE and/or other dealers in the area. They already seemed to have left a message with the tossing of cash at KR's death scene. Seems logical there could have been other messages included in the other deaths.
Just thinking out loud. Any other ideas?