Most have been able to determine, (imo), that the Cox family by and large chose to live off the grid and it's what their family was accustomed to. From what we can ascertain, it's the way LVD lived her life. Very little was owned, most everything rented, very few material possessions (although it's obvious they like nice things) but for the most part they lived their lives undetected and off the grid....until now.
I don't think these people are very complicated, I think, in my opinion, they're pretty base. I just don't see a whole lot of thought going into planning all of these murders/events.
I think they live(d) in the moment, I think they acted in the moment, and I truly think they never once thought about digital footprints or even the remote possibility they were being followed. I don't believe there was ever much thought regarding anyone paying any attention to what they were doing. Other than Charles, who even the police did not put any stock in what he said or his murder, which furthered their ability to continue in the mindset I am describing.
As far as CD is concerned, It would appear he was pretty sheltered in the world he and his wife had created for themselves and their children. His book/author world was the lemon bulb that caused this sheltered, pretty much basic individual, to feel his oats, when he spotted LVD and she most likely flirted with him, which took his basic, unattractive self, to an all new level of lust over logic. (imo)
The basic...ness of these people (imo) was proven when the police first came looking for the children, the reactions were definitely reactionary and not at all proactive.
I think once the trial gets underway, and we see all of the evidence that was accumulated, we will all be quite surprised, or maybe not, at the level of ignorance, in this operation. Additionally, I do not buy the religious aspects, because I think they were used only to justify their actions to family and friends.
Like I said I think it's all pretty base....