The second study did not sit right with me. The data set that they used was problematic, and the fact that they are testing for an intangible of bias is another problem with the study. One major part of the research is they coded by crime, but not all areas are policed the same, policing in Scottsdale is much different than in Pheonix so how can you get a fair and equal sample size to begin with? (why most researchers use population as a metric)
"Until now, researchers have been unable to test questions related to officer characteristics in fatal shootings. We created a near-complete database of fatal shootings in 2015 to test questions about racial disparities in FOIS."
The until now, comment is the academic version of Neva' Been Done Befo'! Also, how can the database be complete when they only surveyed 400 some odd police agencies compared to the over 10,000 that operate in the United States?