I think they moved on too quickly from the Dermond's family members. It is extremely disturbing to think that a (or more than one) family member could do this to their parents, but it does happen. Look at the Menendez boys. That was a very brutal and disturbing crime.
Let's assume this crime was staged to look like a particular type of crime. What would it be? I think most people would think "cult-like" because of the beheading. Within two weeks of the murders, one family says he believes it was the act of a cult. He goes on to say he does not believe it is random. How does he know? His parents were just massacred and what does he know about murder investigations.
Robbery? No. Nothing was stolen even though there were many valuables easily available. Why no robbery. Is it was orchestrated by a family member, (1) those belongings are valuable to the him/her, and (2) items like expensive watches, etc. could lead back to the killers (probably hired).
Who benefits? The heirs.
A revenge killing? No. The killings appear to intentionally happen outside of the home. Why? The home is a valuable asset to an heir. Random killers, revenge killers, professional killers do not care about keeping the house clean and valuable.
The beheading? To infer the "cult-killing" theory. But in reality, cult-style killings are usually not well thought out. They typically are sloppy and over the top with some type of symbolism related to religious or other cult beliefs. It might also explain why he was killed before the beheading. Maybe the instructions were to make sure he is dead before you do that. I do not think the beheading is a symbol of more anger towards the male victim than the female victim. I think it is totally related to the staged murder scene. Would hiding the female body in the bottom of the lake delay probating the estate? I do not think the intention was to hide Mom's body for any great length of time. Anyone who planned this very detailed crime would have done sufficient research to know that the body would eventually come apart in the water and be discovered. I think the manner of disposition of Mom's body was just another tactic to make the scene even more bizarre, but also to distract law enforcement from the home crime scene while they search for what may be a living hostage.
Keep in mind the person most likely to pass a polygraph is a true psychopath. Not only do they lack any empathy for the victims, they have often convinced themselves that their crimes are justified for some bizarre reason. A true psychopath might just decide he is tired of waiting for the money and that the victims have lived a long life and it is time and, for some reason, that is okay.
They need to look further. Particularly, the finances of some of the family members. For one, the lack of a reward from the family is a little disturbing to me. If they don't have the personal funds, they could have filed a request for the estate to post a reward. While you never want to just throw tons of money out there because it often triggers so many false tips that the investigators are overwhelmed, $55,000 doesn't seem sufficient in this case. Not certain, but I believe most (or all) of that reward came from the community.
There needs to be a thorough investigation into the finances and businesses of the family members. It could be that a family member wanted to do as well as the Dermonds, but struggles. That person would probably have filings for several businesses and, although they might look successful, there will be signs that the businesses never come close to what the victims were able to accomplish. And, at this point in their life, the victims may have said no to requests for financial assistance.
The truth is, the prosecutor does not have to prove motive and that should not be the focus of the case. This crime was planned out very thoroughly. The location of the home and access to the home by boat is not something random. It just didn't happen that way. There is no evidence this was a spur-of-the-moment robbery. In fact, the evidence almost rules that out. There were tools/weapons brought to the scene(s) specific to the acts that took place. The victim's head was not severed with a kitchen knife. The cut was clean. The cinder blocks and the bag they were in were not just something the killers stumbled upon. This was not a botched or abandoned attempt at extortion. Killers capable of these brutal murders are not going to develop a conscious mid-act.
One killer or two? I think common sense tells us two, but that truly is just an assumption. One person, particularly someone who would be able to separate the victims because the victims felt comfortable with the killer, could have done this. Nothing says that both victims were in the garage at the same time. If one victim can be lured to the garage and then the other convinced to take a boat ride, one person could commit this crime.
I can't really explain why Dad is shot, but Mom is hit with a hammer. My only thought it was a attempt to leave no evidence on Mom's body, or it was a younger relative who somehow thought the hammer was less violent to her. There may not be a rational explanation for that as this whole thing is irrational.
While it isn't major in the scope of things, I would like to know if the female victim still had her wedding ring on. Such care was taken to preserve everything of value, I just wonder about her ring.
