Fewer Traffic Stops Following Legalization, Yet People of Color Still Disproportionately Targeted, Finds Study

According to a new study published in the journal Nature: Human Behavior, police are less likely to conduct searches for illicit contraband during a traffic stop following the enactment of adult-use marijuana legalization, but people of color are still targeted at unfair rates.

For the study, first reported on by NORML, researchers from Stanford University and New York University assessed the effects of statewide legalization laws in Colorado and Washington on traffic stop outcomes. Investigators reported, “After the legalization of marijuana, the number of searches fell substantially” in both states as compared to rates in 12 control states (jurisdictions that did not amend their marijuana laws). In addition, “the proportion of stops that resulted in either a drug-related infraction or misdemeanor fell substantially in both states after marijuana was legalized.”

However, despite the overall decline in traffic stop-related searchers, authors reported that African Americans and Hispanics continued to be subject to vehicle searches at disproportionate rates. “We found that white drivers faced consistently higher search thresholds than minority drivers, both before and after marijuana legalization,” they wrote. “The data thus suggest that, although overall search rates dropped in Washington and Colorado, black and Hispanic drivers still faced discrimination in search decisions.” Nationwide, African Americans’ and Hispanics’ vehicles are searched about twice as often as are those of white motorists.

The study concludes “We find that legalization reduced both search rates and misdemeanor rates for drug offences for white, black, and Hispanic drivers – though a gap in search thresholds persists.”



Their findings “are similar to those reported in a 2017 analysis by The Marshall Project and the Center for Investigative Reporting. In that study, researchers reported that traffic stop-related searches fell among both whites and African Americans post-legalization, but that blacks still remained two to three times more likely to have their vehicles searched.”

Commenting on the new study, NORML’s Political Director Justin Strekal said, “While we are pleased to see the total number of traffic stop-related searches decline in legal cannabis states, we must not overlook the reality that people of color continue to be policed in a racially disparate manner. While legalization is one tool that appears to lessen some of these disparities, it is not a panacea to solve the structural problems of systemic racism that persist in America.”

The full abstract of the study can be found below:


We assessed racial disparities in policing in the United States by compiling and analysing a dataset detailing nearly 100 million traffic stops conducted across the country. We found that black drivers were less likely to be stopped after sunset, when a ‘veil of darkness’ masks one’s race, suggesting bias in stop decisions. Furthermore, by examining the rate at which stopped drivers were searched and the likelihood that searches turned up contraband, we found evidence that the bar for searching black and Hispanic drivers was lower than that for searching white drivers. Finally, we found that legalization of recreational marijuana reduced the number of searches of white, black and Hispanic drivers—but the bar for searching black and Hispanic drivers was still lower than that for white drivers post-legalization. Our results indicate that police stops and search decisions suffer from persistent racial bias and point to the value of policy interventions to mitigate these disparities.

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