<BBM for Focus>
I agree Steleheart, Sheriff Sills, should be looking way back, just not at the Dermond's history. Sheriff Sills should be looking at himself in the mirror asking, who is capable of comitting a heinous crime of this nature? Who has a documented past of extreme violence and other deviant behavior; murder, dismemberment, etc. I agree that there is someone serving time in prison who has had many years to plot his intricate plan to seek revenge/retribution.. This person, as are many sadistic psychopaths, is very intelligent, creative, calculating, but most importantly, very deflective..
Imo, the intent of Mr D's decapitation, taking of his head, and posing of his torso for discovery was not to remove ballistic evidence but to instill terror. Terror for the person/s that discovered him, the community, and investigators and other first responders that witnessed the grisly crime scene.
Imo, Mrs D life was spared until arriving at the body dump location. Mrs D was simply used as a shield/hostage, in case the perps's boat was stopped by DNR enroute to the boat launching ramp, imo..
I don't know about Mrs D being used as a shield/hostage because once they killed and dumped her, they were still vulnerable to a DNR search going to the boat ramp or even being spotted by someone who knew her. Maybe their boat ramp was a private ramp near the dump site? What about all the homes immediately in the area of the dump side?
Also, there would have been the possibility of a blood splatter in the boat, whereas if they had left her at her home, there would be no link at all - unless they had blood on their clothes.
The guy spotted in the front yard could have been using the hose to wash blood off his hands and the knife? at the time. I have read both front and back yard, but I wonder if it's just how you interpret the position of the house? I'm used to calling the part facing the road/street the front of the house whereas someone living on a lake may say the front of the house is facing the lake.