Well I think gas station and parking lot is just an easy shot. He also shot a guy moving his yard. I mean when you pump gas what are you doing... Standing still. Parking lot too. it you are loading a car with bags you are in one place for a few minutes.
There are theories about AL QAEDA but dosen't seem thiere style. They usaly attack many people at once to cause terror. This is too.... slow and puney to be thier style.
I think this is a Hunter that wanted to hunt bigger game. Or something along those lines.