Idaho

They usually are very careful not to overcharge. That was the last thing I expected. That means he seems to have had motive and planned to kill all four of them, with just a knife. I would guess he had a gun too but didn't want to use it.

He also seems to have known he was leaving someone alive there that saw him.

I live about 35 miles from there and he was tracked coming down here to our Walmart the next morning, I think. That's interesting, since both Pullman, WA and Moscow, ID have their own Walmart's about ten miles apart. I wonder if they also know what he bought down here if that is the case.