RSBM.... NO....... Sometimes I think what KD said is what someone wanted it to look like
A cult...........
Not sure I've ever really thought about it like this before, but yes.. in whose mind would such a thing as a cult killing come to mind on this? Especially having some knowledge of that crazy Newabian(sp?) case. Maybe perhaps only someone(s) who wanted it to look like that? No matter how one slices it... 99% of the possible options would include a messy gruesome scene where not much care or thought would have been given.. the cleanliness of this event, imho, rules out so many possibilities.. such as random, home invasion, thrill-kill, mob-hit, some kind of crazy cult thing, sex assault, robbery, etc. If extortion, a failed one, since obviously the Ds did not have what was wanted, where is the huge mess of anger? Instead we have nothing touched, no prints, no DNA, and a clean cut - which doesn't look like a lot of sudden anger. 'Looks' like a crazy, but the other facts don't fit. Unless someone was trying for a 'wannabe looks like a crazy'.
What's left? Not a whole hay of a lot, except for one big elephant in the room. imo.
ETA: add 'drug-induced killing' to that list above since such a murder would also have left a big mess.