In 2002, a study by Joshua Correll and colleagues, called The Police Officer’s Dilemma, revealed a phenomenon also known as shooter-bias 

The study found that people hesitated longer to shoot an armed white target (and they were more likely to accidentally not shoot). Participants were quicker and more accurate with black armed targets but there were more “false alarms” (shooting them when they were unarmed). These effects were present even though participants did not hold any explicit discriminatory views and wanted to treat all targets fairly

Read More