In the beginning, there was nothing. No police parking spots that is, at the Walnut Creek Target. Years later two police parking signs appeared in the Target parking lot, closest to the store. And now, as you can see in the above photo, there is only one. According to a Walnut Creek employee I spoke to, the additional spot was no longer needed.
If I remember correctly a few years ago there were some Craigslist exchanges happening in the parking lot here and some people got robbed as they handed over goods they planned on selling. That’s probably why those spots were added. Personally I don’t see why they need to reserve the best parking space for this; a couple of rows back in the corner is right near by and would serve the same purpose I imagine.