The Erie, Pennsylvania pizza bomber came to my mind, on reading the excerpt.
Glad some adult found the remains, and not some innocent kid or kids. 5:15 a.m. is pretty early time to be walking the dog, I wonder if the adult was looking for the site of the explosion.
Not if you have to be downtown by 8 or so. If you're taking Metra into the city you'd probably want to be at the train station by 0630 or so. When I was doing that trip from the burbs I was walking my dogs at about 0530 or so.
If this guy set it off just walking down the street I'd put my money on TATP as the compound involved. That stuff isn't called Satans Mother for nothing.
I'm generally out running with the dog by then....
Maybe but if he works he probably has to walk his dog early. And yuck, not what I’d want to find early in the morning. Or any time.