Each year, the Missouri State Attorney General collects data from police departments all around the state that gives us a better look into the interactions that officers have with drivers who are stopped by law enforcement while driving. This data is then aggregated and released to the public as the Vehicle Stops Report (VSR).
The St. Louis City Police Department covers one of the largest and most racial diverse jurisdictions in Missouri – roughly half of the city’s population is Black, and the other half is White, according to census data from 2010, the most recent available.
The main metric that the VSR uses is the disparity index, which represents a racial group’s vehicle stops relative to that group’s proportions of the Missouri driving age population. Based on data gathered by the St. Louis Police Department (SLPD), Black drivers experienced 66.4% of the vehicle stops performed by their department, despite only making up 45.7% of the city’s population.
This created a disparity index of 1.45 for Black drivers in 2018. White drivers, however, only saw a disparity index of .66, meaning the stops they experienced were far less frequent than one would expect given their share of the city’s population. Comparing these two disparity indexes, we can confidently say that Black drivers were 2.22 times more likely to get pulled over by the St. Louis Police Department as white drivers.
“The difficulty comes in identifying the causes for disparity,” Kevin Merritt, executive director of the Missouri Sheriffs’ Association, said in response to these findings. “Race alone is not dispositive of why the stop was made; neither is a disparity index.” This is an understandable reaction. The data in the VSR does not show an officer’s intention when pulling someone over. In fact, some of the data submitted by the SLPD supports the idea that officers from that department did not, in 2018, take actions that are typically associated with racially biased policing.
One metric that is used to show an officer’s potential bias is search rates. If an officer is searching the vehicles of members of one race much more frequently than members of another, one could argue that the officer in question is basing their decisions on the drivers race. However, the SLPD did not search the vehicles of Black drivers more than white drivers, at least not at a statistically significant rate. The difference in search rates for the two races was less than 3%.
The reasoning officers gave for why they searched stopped drivers was also statistically insignificant. In the past, the statewide data in the Vehicle Stops Report has shown that officers would sometimes choose to ask more People of Color for consent searches. In 2018, that was not true for the SLPD.
So, if the data shows that officers are not showing a racial motivation in their decision making around searches, why does it also show such a significant racial disproportion in stops?
While St. Louis is a more racial diverse part of Missouri, it is also highly segregated. The Racial Dot Map, created in 2013 by Dustin Cable at the Weldon Cooper Center for Public Service at the University of Virginia, shows something that most St. Louis citizens already know – the city is geographically divided by race, with a majority of Black residents living on the North Side of the city, and the majority of white residents living in the South Side.
This is one potential explanation for the disproportion. It can be argued that individual officers may not always be able to tell the race of a driver before the stop is made, meaning it is more likely that these disparities are the result of SLPD over-policing parts of the city that have Black residents. It may be wise for the Attorney General to mandate that officers also submit the exact location of their stops to the Vehicle Stops Report. This may help us to better understand the significant disparity we see in St. Louis and other parts of the state.
There is one more data point that is worth mentioning. When it came to the results of vehicle stops, the SLPD was 15% more likely to write citations for Black drivers, and were 7% more likely to take “No Action” if the driver they pulled over was white. There is also an unidentified “Other Result” category in the data. SLPD was 10% more likely to say that there was an “Other Result” when they stopped white drivers than when they stopped Black drivers.
The Vehicle Stops Report is an important tool to use when organizations like Empower Missouri and other concerned citizens want to understand the problems our state faces with regard to interactions between police and the communities they are meant to serve. Empower Missouri is happy to furnish data analysis similar to what is provided in this piece for community groups or police departments looking to have meaningful conversations that can lead to important change.