Here is info on the AZ couple referenced in the LA Times article:
For what it is worth, the area where the AZ couple was shot is rural high desert, and that area is rumoured to have an anti-social, anti-government conspiracist "vibe" to the few residents who live there. I used to live south of that area. The area where they were found is not heavily populated, usually the only people you would find there are those going up to Crown King (the road by Bumblebee is one of only 2-3 roads up the mountain to Crown King). There are however, alot of trails in that area for four wheelers. If the same guy is doing all of these shootings, that area would have been a perfect place for him to "hide out".