Potential energy vs kinetic energy. Just because it is not in motion doesn't mean the potential is not there, that's why everyone has Amazon Ring in front of their homes and won't let their kids alone in the park. Relying on police to deter crime or relying on police reports to understand the current crime landscape is beyond naive.
More importantly, you can't deal with potential crime by making real arrests, because then you have to start arresting people who haven't done anything.