In a country the size of the USA there will be thousands of police enforcement incidents occurring every day. Some of these will inevitably involve mistakes due to genuine errors of judgement or deliberate acts done by corrupt employees within the police force. Hopefully, such incidents will form a tiny minority when compared with the total number of justifiable incidents. There is an obvious danger of over-interpreting a tiny minority of selected bad eggs within these thousands of incidents and extrapolating them to indicate widespread racism.
I know that you are not trying to defend the indefensible, but I would draw your attention to posts on this Forum relating to the British police.
A copper does a good deed, protecting innocents from a knife attack by an Islamic fundamentalist and not a word shows up in praise of such actions as it is 'part of the expected actions that go with the job', but let any copper step outside the accepted boundaries of police behaviour and the shit-slinging is of monumental proportions as if the bad eggs are the norm. #234 above is a case in point!
Obviously the press coverage of American 'bad eggs' is greater due to the problems caused by all officers being armed and the frequent use of those arms.
I agree that such incidents, should, in a perfect world, not occur ever, even once, but we are all, including the coppers, human and as such not one single one of us is perfect.
Only one man in the entire history of humanity has had that claim made on his behalf and he was crucified!