Shine the flashlight on him and give him the opportunity to leave. As long as he does, there’s no mess, no stress, no lost sleep, and not even any lawyers to deal with.
Mary was nothing if not neat. The brains and other "stuff" were outside. If the cops hadn't come, Pig Man's charges probably would have come and cleaned up. Pig Man lived on land adjacent to Mary's but with no direct frontage on the roads.
I don't know who he was, but most of the land thereabouts belonged to my Lee or Harrison ancestors.