Acceptable at least in the sense that there's not widespread revolt against it.
A couple of US style incidents in other western european countries would have toppled the government or at least the justice minister -- and yet tons of them happen in the US with little to no protest (aside from special activists and groups).
Acceptable also in the sense that it's the prevalent wisdom: "don't do this or that, or you'll might get shot/tased/etc", which people have internalized, instead of considering something rare and outrageous.
The fact that a cop can shoot someone (black or white) just like that, and that it happens tons of times a year, is not much different to my European sensibilities than still having the segreggation. Or still having the death penalty -- oh, wait, they have that too...
I refer to the fact that you can be tased, shot, beat, arrested, held down by 4 policemen, beaten etc 10 times more easily than you can in Western Europe -- and people think that's OK, or what "the police is supposed to do".
Even the fact that getting out of your car when stopped by a traffic cop (something totally OK in 99% of the world) means you can be shot in the US...