What @charminglane said...was one of my questions. I know we used to have restrictions where I live - permit required and limited to a certain # per year. I was surprised that was no longer the case for me. So that tosses that theory.No permit needed. And garage sales on Fridays are so common here in Texas. A lot of people have Fridays off.
Also, I know this gets mentioned a lot, but I haven’t seen it lately. The Nissan truck did drive by their house around 2am that morning. Probably trying to familiarize themselves with the route that they were going to take. So it seems unlikely that this was just someone that could have seen a garage sale sign and wanted to steal something.