First of all, the homeowners released a bunch of video showing people from all over the neighborhood wandering in and out of that construction site. None of them took anything, none were sought or accosted, and certainly none were shot dead in the street, except Arbery.
Second, he was literally jogging, you can see it in the video. Frankly, though, even if he was jogging along with the recently-stolen Hope Diamond in his pocket, it doesn't matter. Private citizens still can't hunt someone down and accost him at gunpoint because of the minor crime they thought he might have done.
Third, it is my experience that when federal charges come down, they're pretty sure they've got the case wrapped up already. These guys should probably get ready for a long stay at the gray bar hotel.