Even before a series of police shootings of blacks last year, most Americans gave police departments around the country relatively low marks in treating races equally. In a survey conducted shortly after the August 2014 shooting of Michael Brown in Ferguson, Mo., about one-third or less of Americans thought police departments nationwide did a good or excellent job of holding officers accountable for misconduct, using the appropriate amount of force and treating racial and ethnic groups equally.

Source: 5 facts about race in America | Pew Research Center