Like so many other safety and privacy things, the difference is simply the scale and automation. Like how there's little philosophical or legal difference between a detective sitting and listening to your phone calls and an automated system scanning them and listening for keyword.

But the real consequences are very different despite that! The automation allows it to be used more freely at low cost, to go "fishing" for crimes rather than investigate a specific instance. And a wider net will catch more false positives, and with the shotspotter having cops show up guns blazing to teenagers with fireworks for example is a heavy consequence.

Since these choices affect peoples' lives in real ways, we're obligated to consider the actual effects, rather than the philosophical foundation. It may not be "any different" in an abstract sense, but this concrete instance is very different and we have to consider that in its use.