I can tell you right now, you are not going to like this essay from Fred On Everything. I didn't like it, and yet it shows some sense. You should read the whole thing, but this part especially stands our for me:

As a fresh cop, you will notice that the standard editorial notion, that cops are heavily armed brutes amid a helpless unarmed populations, isn’t quite accurate. When you are on the sidewalks of a bad neighborhood, where you know you are disliked by all and hated by many, you will become aware of your vulnerability. You have to pass close to people. Any of them could blow your head off from behind, stick an ice pick in your back, or brain you with a piece of rebar.

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Ah, but how do you know when your life is in danger? Therein lies the rub.

As an object lesson, watch the following video where an armed (!) police officer gets beaten senseless by an unarmed (!!) assailant:

Now, if she had shot him, we would have heard about another white cop killing an unarmed black man. But as we can see, "unarmed" does not mean "harmless, timid, or otherwise not-dangerous". She was lucky that he did not kick her head in while she was down. Keep this in mind the next time you hear about someone being "unarmed."