"APCs are very useful when...."
The situation you describe is a one in a billion chance, there have maybe been a handful of them in the last few decades nation wide. Most recent incidents involve a nutcase running around killing as many unarmed people as possible, they aren't camping out waiting 45 minutes or more for the police to roll up in armored vehicles. By the time they get the APC loaded up, started and driven to the scene probably 97% of incidents are already concluded (shooters dead, surrendered or escaped) and those that haven't probably could have been solved 30 minutes earlier by a few officers, some vests, a few rifles/shotguns and a well planned entry. I'm not saying that police don't need access to them on very rare occasions, but one APC per million citizens is probably too much, where as we're seeing police departments as covering areas of less than a 100,000 trying to get a couple of them. And also having too many of them them seems to see their use as often as possible, a minor drug arrest or some off hand remarks can result in one rolling up in your yard with a half dozen heavily armed police piling out of the back of one like they're afraid you've got a nuke in your basement.