Josh Correll in “Unfinished Business”

  It's worth noting that, in this game, people are pretty good.  They don't make a ton of mistakes—ten, fifteen percent of the time they make a mistake.  But when we look at those mistakes, we see racial bias in the errors.  So they're faster to shoot the armed target if he's black rather than than white.  When the target's got a cell phone, they're much more likely to make that decision, to shoot an innocent target, when he's black rather than white.