https://www.washingtonpost.com/graphics/national/police-shoo...
And the vast majority of those were clearly justified (suspect being armed and posing an obvious threat threat.)
Police are far from perfect but they also have to deal with people on a daily basis who are quite literally the dregs of society: where "F--- you pig!" is as common as "Thank you Officer."
As far as inbuilt racial bias -- have you spent time on the streets? You tell me what the percentages are for a crime being committed among different racial and ethnic groups. If you're in Chicago you are far more likely to be shot by a male of a specific racial group than by any other. That's just a fact. Nothing racist about it.