I had trouble falling asleep last night, as I know many did, with all this going 'round in my head -- first, the awful sadness of it all, then trying to figure out scenarios of how it may have happened.
One POSSIBLE thing I thought: Suppose he set up a meeting place with them -- some say maybe a store, that's not from MSM, though. But say an old abandoned store. He might have said: "There's this old store, kind of a landmark - meet me there and then y'all can follow me to my place, because it's a little bit hard to find. I'll be driving a (whatever kind of vehicle) --when you see that. that'll be me."
So the Runions arrive at the meeting spot, park their vehicle to wait. Perp is concealed in nearby woods -- the plan is to come out, masked and disguised and with a weapon, and hold them up right there. In other words, try to make it look like someone OTHER than the "Mustang-owner" sees this older, Atlanta-area couple parked in this remote spot in South Georgia and decides to rob them (Nah, not a good plan either -- just one way he MIGHT have thought he could get money without killing.)
But maybe Bud balked, or Bud had a gun, too, or -- something.