If the police get to decide the crime being committed, and the police are biased, and the police are the ones who ultimately write the reports that were evaluated for the study, how would the study detect that bias?
Ask the author of the study. He addresses this when he says, "Relatedly, even police departments willing to supply data may contain police officers who present contextual factors at that time of an incident in a biased manner -- making it difficult to interpret regression coefficients in the standard way. 6 It is exceedingly difficult to know how prevalent this type of misreporting bias is (Schneider 1977). Accounting for contextual variables recorded by police officers who may have an incentive to distort the truth is problematic. Yet, whether or not we include controls does not alter the basic qualitative conclusions. And, to the extent that there are racial differences in underreporting of non-lethal use of force (and police are more likely to not report force used on blacks), our estimates may be a lower bound. Not reporting officer-involved shootings seems unlikely."
I'll be honest, I don't know how he comes to the bolded conclusion. I have not read the entirety or even most of the 63 page PDF. That said, I trust his statistical approach a lot more than political agitators trying to spin a narrative based on a few cases.
It really does not follow to come to a conclusion that police use excessive non-violent force against blacks, but not excessive violent force.
That's also covered in the paper: "We argue that the patterns in the data are consistent with a model in which police officers are utility maximizers, a fraction of which have a preference for discrimination, who incur relatively high expected costs of officer-involved shootings."
But then, consider: in the past few years we have been presented with videos of officers shooting unarmed blacks, in which the blacks would have been found at fault had it not been for the video evidence.
And you can find videos for non-blacks too. You just don't get national media coverage of them and riots in the streets.
At present, I don't see how anyone can say "Clearly, blacks are not being wrongly killed."
I never said that. Please don't strawman.
As for cops vs blacks and blacks vs blacks, I see no reason why we can't strive to improve both situations.
Narratives and motives matter. You can't respond rationally to a situation when false narratives are spun by leftist agitators that draw inspiration from cop-killing, communist terrorists, and a media that is unwilling to view the situation critically. That includes responding proportionally to situations. The tangible result of Black Lies Matter are assassinated cops, riots, and a rise in murder rates, along with a country more divided by race in a long time, despite any rational reason for that to be the case.