> Flock would have detected, but maybe not prevented, two of these cases

I'm glad you acknowledge this, because it highlights what has irritated me about the discussion of crime in the last ~6 years. People seem to expect that crime can be prevented. Our criminal justice system and system of civil rights can only intervene after the crime has occurred, which means it won't prevent anything. Maybe I've misread you personally, and I don't mean to put it all on you, but I think people with your position tend to vastly overstate the deterrent factor of proposed interventions.

Further, only reacting to crime and not seeking to "punish" people before a crime has occurred is exactly how our system should work. When reasoning about crime prevention, a large number of people seem to want police to intervene preemptively. Or they want to punish offenders out of proportion to actual crimes, to prevent recidivism that hasn't happened yet. This type of thinking seems to slide pretty quickly into the "pre-crime" concept of dystopian scifi. We called that stuff dystopian for a reason.

In my opinion what we should do instead to prevent crime is to promote social cohesion, in the form of preventing income and wealth disparity, funding a strong social safety net, help for drug addicts and the mentally ill, etc. People who live happier, more stable lives will have less reason to turn to crime.

(I will also note, crime is lower everywhere in America vs. a few decades ago. Violent crime peaked in the mid 1990s. So it is in some sense a misguided endeavor completely, focusing on problems that are relatively unlikely.)