Because ALL TOO OFTEN THEY DO brutalize or murder unarmed black people and peacefully arrest armed white mass murderers. No one said they kill black people at *every single interaction* with them. But again, it happens disproportionally and when it does, they need to be held accountable. Try to keep up, Trausti.
Reality check:
Police shooting rates vary by the location, but within a location we do not see a racial bias.
Likewise, when compared against the number of arrests whites are actually slightly (but below statistical significance) more likely to get shot.
The only racial pattern we see at all is more "unarmed" blacks getting shot--but this ignores the fact that trying to take the cop's weapon is a completely valid reason to shoot. (It would be a completely valid reason for a civilian to shoot as well.)
Quit defending the bad guys, focus on the real problems--the George Floyd's (police administering a bit of street justice) and the Breonna Taylor's (reckless behavior in pursuit of drugs) of the world. When you lump these in with the Michael Brown's you make the real problems look fake rather than make the fake problems look real.