An unlocked door for the perps, I think holds possibilities. Or, good access to an unlocked door. Sherill may have awaken when the girls arrived home, but never got up to greet them, just turned over and went back to sleep. If they came WITH anyone, different story, of course, but that would be irrelevant for this purpose. But, the girls get home, mom stays in her room, door the girls use never gets locked and that would be one way. Another is, if anyone knows, another key that would have been left outside, i.e. under a mat, covered over just outside the door, in the mailbox...anything, that a curious and exploring perp might have checked for. I personally have never kept spare keys near my home like that, but I see the practice done quite frequently.
Mule, I know you are very open to the idea the girls never made it to the house and the cars were planted there, after the girls were captured from somewhere. Certainly not impossible, but I'm more open to questioning other aspects of this case before that. To me, the mechanics of orchestrating something like this are a bit much. It does defend robbery as an extraneous and worthless motive, for if that was part of it, steal the cars to and send them to chop shops, while you walk off with hundreds. Still, while very possible, I'm inclined to believe the girls arrived at the house, perhaps followed, known or unknown, friend or foe.
We have some newer posters who have joined us, and they've raised some interesting issues, and reaching a similar conclusion I have at this point, at least. With so little physical, even hard evidence, the State has pretty much struck out. It seems they were playing poker early in the game, didn't get the brakes they thought, hands are called and they have junk. Numerous accounts of where people were that weekend, what people said (or are reported to have said/done), all of which could have holes shot threw them by a decently skilled defense attorney. Various physical artifacts but no 'ah-haaa' to them. I go back to the remark recently by one of the investigators, currently on the case, to the effect, '...let's remember of the time which elapsed before police were called...' The finger pointing of an acquittal before any arrest has been made.
Lastly, it's been pointed out to me, by many in the legal profession, sometimes very crassly but still earnestly, that the legal system is about winning and loosing. Guilt or innocence is not really the point, you must PROVE it...'beyond a reasonable doubt.' And, in our system, that falls on the State. The theory is, the State has vast resources and authority which could easily crush the innocent individual. Placing the burden on the State levels the playing field. Problem is, if the State's case is obstructed, by just circumstance or fate of events, a weak defense can still win. Some academics point to the Scottish system as an example. We have 'guilty/not guilty,' the Scots have 'guilty/not guilty/not proven.' This puts more burden for an acquittal on the defense, and leaves a legitimate cloud of suspicion if the State fails to prove guilt for a conviction. It also brings the benefit of airing out, in a controlled courtroom, issues pertaining to the case and have them played out, without the State shooting for 'conviction or broke.' This was also raised during the OJ Simpson trial as a remedy to our system of 'winner take all.' While this flies in the face of our system, Scotland is a modern Western country, built on Western traditions and the UK is ancestral to our system. But, it could also be raised, as with many small, although very modern European countries, that their societies are far more 'intimate' than our more massive, younger 'American Mix.'