Thanks much for additional be observations. Subdued early on possible attempted to get Ritchie to cooperate, removed from scene . Do you thinking weapons and other items taken out first ?
Need to find out how far closest neighbors were and who they were.
Close friends in the area ? Gun collectors ? Gunsmith he used regularly, survivalist groups or buddies ( teams) that share info and preplan excursions together. (Training) seminars, get aways in secluded camps/ bases ?
Haven't turned up much, but the seclusion and tough terrain would be optimal for this kind of prepping wouldn't it ? JMO MOO
Where are you Ritchie ? In my thoughts and prayers, Ms Britney you are as well, praying for strength and resolve, your thoughts and ideas more than welcome

Hugs)))) Hang in there !!! Keep looking for missing pieces to this !! Here if you need anything. My heart aches for you dear Lady. And your Dad's family and friends.