eliminating the biases of all police officers would do little to materially reduce the total number of African-American killing - http://www.nytimes.com/2015/10/18/upshot/police-killings-of-blacks-what-the-data-says.html?hpw&rref=upshot&action=click&pgtype=Homepage&module=well-region&region=bottom-well&WT.nav=bottom-well