The critical flaw in the system is the obscene notion of 'crime prevention'.
If you are not stopping an actual crime in progress, then any police act to 'prevent crime' is an improper excess of authority exercised against those who are not engaged in criminal acts.
It's a guaranteed death-spiral into totalitarianism. The only way to genuinely prevent all crime is to prevent all unsupervised activity.
It sounds like such a great idea -- who doesn't want to 'prevent crime'?
But in practice, it becomes crimes by the state against non-criminal individuals. A license to dominate, to improperly exercise improper 'authority'.