It’s a bit of a puzzle. Sheet metal work is something I tend to think happens once a building is roughed out, and things like ductwork are usually happening inside. That doesn’t rule out the possiblity of a box of screws falling off a truck — except that over a fairly short time I’d think they’d all find their way to the gutter. To further belabor it, gravity dictates that a screw will lie on its side, making bullseye punctures like mine less likely. Also, it’s the same tire every time — left rear, on the outer part of the tread — street-facing when I’m parked. There’s always more debris on the curb side. But no, I can be certain it’s happening where I park. I figured if another neighbor shared this experience, it might point to random vandalism within a contained area. So, I’m hoping you’re right and I’m not being targeted.
Now that I’m an old hand at it, I can recommend a good repair person — the mechanic at the Shell at Ellicott and Wisconsin. I drive on the spare to his station, and he fixes the puncture while I wait. 20 bucks.