I've been thinking about these questions from everyone about where the murders might have taken place, and where Mr. D was decapitated... Now that we're almost sure they didn't come in or leave by car, the only thing that makes sense to me is that all of this took place on a boat. My
theory is that someone they knew came by, and asked them to go for a boat ride, maybe to watch the sunset? A few years ago, we would often be playing out on the water all day at our lake house on Jackson, but the only time my elderly dad would ever go out for a boat ride with us was at sunset/happy hour. The water would be calmer, the lake peaceful, stars starting to come out...you get the picture - we wouldn't stay out long, but it would always be almost dark by the time we got back to our dock...
This is how
I think the person they knew got them into the boat, then maybe they pretended to break down or something, staying on the lake until after it's dark enough, then hitting both on the head and killing them there in the boat. There are MANY secluded areas on Lake Oconee, uninhabited coves and shoreline where it's just woods with no one around - it would be easy to find a spot where they could appear to break down, spend a while pretending to try to start the boat until it was completely dark, then eliminate the couple. I think they then drove to the spot where they dropped Shirley's body hoping it would become entangled in the tree stumps and never be found, then drove Mr. D's body back to the house. Somewhere along the way they detached the head and I think deposited it in a different location from Mrs. D. The mess would all be confined to the boat which could be washed out or maybe they even sunk the boat later in a third location... I think Mr. D's body was wrapped up in something (like some plastic) and the comments about the body being moved or drug "just a few feet" into the garage, were the result of the body being laid on the ground and then drug off the sheet into it's final resting place inside the garage. I think Mr. D's body was returned to the home for either A.) shock value and to throw off LE, or B.) to send a specific message to someone or possibly a message to the "community."
It seems to me that Sills is pretty sure the decapitation happened somewhere else - at around the 4:05 mark in this video he says the following: "Within an hour of responding to this call our
cadaver dogs had searched the immediate vicinity, and wooded area around the home. Not the entire greenspace there
but the ENTIRE area immediately adjacent to that, we've done all that." (BBM)
https://www.youtube.com/watch?v=7utUlmCnZOk&feature=player_embedded
"After the body was found, deputies in a boat dragged the 13-foot-deep water near the couples house. Investigators also called in the cadaver dog,
to no avail." (BBM)
http://www.macon.com/2014/05/08/3087453/decapitation-unlikely-cause-of.html#storylink=cpy
If the murder and decapitation had happened in the yard or on the dock, it seems to me the cadaver dogs would have hit on something in those areas, there would be traces of blood in those areas besides just the spot where they found his body. That's why I think it all happened in a boat. I think this was premeditated and very carefully planned out by someone known to the Dermond's.
JMO