I'd posted in our local facebook community page, and 2 other interesting stories came up.
1. someone posted they'd seen something similar a few weeks earlier. They'd confronted the person, and the other person pulled a gun out and threatened them. I do not know if the original person involved police after that. While it might sound far-fetched to some, I live in the rural south of the US.
2. someone else posted a similar story, and had taken a picture of the person dumping trash in public and posted it to the facebook group. that poster was harassed online, with many people complaining that they were "violating the other person's privacy" by posting their picture online without consent.
I get truly demoralized at time by living in this area (we're planning a move, but possibly not far enough away).