The police? That sounds like a very ineffective solution. People aren't safe because of the police, they're safe because of the trustworthiness of their neighbors. The police can't be there to intercept most crimes; instead they show up to write a report post-fact. But at that point, you're calling the police for documentation of a crime for insurance.

Police can't be there to intercept the metaphorical brick through your window. The reason why we feel safe walking outside everyday is because of the fabric of trust in our community.