NEW STUDY ON POLICE KILLINGS OF BLACK SUSPECTS.

New study on police killings of black suspects. 
https://papers.ssrn.com/sol3/papers.cfm?abstract_id=2870189
"Abstract:    

Using a unique data set we link the race of police officers who kill suspects with the race of those who are killed across the United States. We have data on a total of 2,699 fatal police killings for the years 2013 to 2015. This is 1,333 more killings by police than is provided by the FBI data on justifiable police homicides. When either the violent crime rate or the demographics of a city are accounted for, we find that white police officers are not significantly more likely to kill a black suspect. For the estimates where we know the race of the officer who killed the suspect, the ratio of the rate that blacks are killed by black versus white officers is large — ranging from 3 to 5 times larger. However, because the media may under report the officer’s race when black officers are involved, other results that account for the fact that a disproportionate number of the un-known race officers may be more reliable. They indicate no statistically significant difference be-tween killings of black suspects by black and white officers. Our panel data analysis that looks at killings at the police department level confirms this. These findings are inconsistent with taste-based racial discrimination against blacks by white police officers. Our estimates examining the killings of white and Hispanic suspects found no differences with respect to the races of police officers. If the police are engaged in discrimination, such discriminatory behavior should also be more difficult when body or other cameras are recording their actions. We find no evidence that body cameras affect either the number of police killings or the racial composition of those killings."

 

Interesting, but does not really answer the question of whether there is racial bias.  Such bias is not excusable no matter what the crime rate or demographics.  Both There can be many reasons for correlation that do not involve any causation.  For instance, both ice cream consumption and forcible rape go up in the summer  and down in the winter.