From what little I have read about this group, some red flags jump out to me about how a local zoning infraction escalates to a charges of child abuse/pedophilia and then to a federal land seizure. It appears Sills jumped to the "nuclear option". Especially telling that the GBI backed off supporting him at the time. Getting FBI and DHS involved in this zoning dispute post 9/11 also raises some questions of abuse of authority.
No doubt, York himself was a criminal. I can suggest Catholic priests, Baptist Ministers, Imans and Rabbi's with similar criminal traits.
That being said, this group, as with any "religion" is comprised of "Leaders appointed by God" at the top, and the "Flock" or Sheep, who follow, tithe and contribute to the organization. You can substitute this structure among any of the organized religions good and bad. Some of the "Flock" may have contributed entire life savings to the organization, only to see their leader imprisoned and their "temple" destroyed, the land sold from under them.
Depending on personalities involved, there will be "True Believers" who will continue to defend the religion and their "Man of God" who has been "crucified". (Familiar theme?)
I don't think it is a far reach that a follower or followers of this group may have targeted someone in the local community to "sacrifice". In fact, their may be some nexus between the sons murderer and imprisoned followers of this religion. IMO Sills is the target, and the Dermonds used as an example of more to come.
Now I have another theory, but best left unsaid.