Philando Castile had a broken tail light, so he died. Sandra Bland failed to signal before changing lanes, so she died. Daunte Wright’s tag was expired, so he died.

Each of these incidents involved a pretextual traffic stop–when police officers use relatively minor offenses as a reason to conduct a traffic stop. According to the Stanford Open Policing Project–the largest study on police stops in history–Black drivers are more likely to be pulled over by police officers and one-and-a-half to two times more likely to be searched. “When we apply the threshold test to our traffic stop data, we find that police require less suspicion to search Black and Hispanic drivers than white drivers,” researchers noted. “This double standard is evidence of discrimination.”