traffic-enforcement-170218-epd-pix

On primary election day last week a non-profit advocacy group called Injustice Watch posted a story on its website that labeled Evanston as having the “worst” record in the nation for searches following police traffic stops.


A Note on the News


The story was based on a research paper by a University of North Carolina political science professor that the author says has been accepted for publication by the Duke Forum for Law and Social Change, a student-edited publication at the Duke University Law School.

The research paper examined searches following traffic stops by 132 police agencies in 16 states, and, looking only at the number of stops and number of searches by race, calculated that a black motorist stopped by police in Evanston was seven times more likely to be searched than a white motorist stopped by police here.

It was an interesting story that caught my eye, but I decided that it required further research before I’d do a story on the subject for Evanston Now, for the following reasons.

First, the study did not look at the outcomes of searches — whether contraband was found — even though that data is available for Illinois police agencies. Without knowing how frequently a search turns up contraband, it’s impossible to assess whether police are making good decisions about who to search.

Second, the study did not incorporate an assessment of a department’s overall search rate into its evaluation of a good performance. Thus, a department that indiscriminantly searched, say, every fifth driver regardless of race and regardless of probable cause would win a prize for no racial disparity under the criteria used by the North Carolina researcher — even though that department might be subjecting thousands of drivers of all races to pointless searches.

It ended up taking almost a week to put together Evanston Now’s own report on the issue of police stops and race, which we published yesterday.

It compares Evanston to all other police departments in Illinois, using data from reports compiled by the Illinois Department of Transportation.

Our study split out two types of searches that had been combined in the North Carolina study — ones conducted by police officers themselves and ones conducted with the aid of a police dog. And we found some strikingly different results across those two search types.

Our story’s findings do not imply that there’s no room for improvement here, but they suggest that, considered in appropriate context, Evanston is probably far from “the worst.”

I encourage you, if you haven’t already, to read our story.

Bill Smith is the editor and publisher of Evanston Now.

Join the Conversation

5 Comments

  1. Thank you for engaging in the

    Thank you for engaging in the effort to clearly decipher these studies thereby hopefully prevent ing folks from jumping to premature conclusions.

    I was wondering what percentage of searches involve those with criminal histories.  

    1. Criminal records

      Hi Emm,

      The available data from the IDOT reports does not indicate what, if any, criminal records drivers who are searched may have.

      The quotes from Chief Eddington indicate that criminal records sometimes are a factor — but that doesn’t provide the detail that would let me come up with a percentage.

      — Bill

      Update 3:40 p.m.: Looking over some partial data I’ve received from EPD for 2016, I now see that it says 0.7 percent of EPD traffic stops of whites and 2.1 percent of traffic stops of minorities last year were done for “investigation” purposes. Do not have equivalent data for the prior years.

  2. Searches by police in traffic stops

    Your focus on outcome of searches, rather than outcome of stops (i.e., searching the driver) distracts from the fact that the search itself is problematic. People have a constitutional right to NOT be subject to unreasonable search, and the fact that there is such a huge racial disparity in searches is the problem. Search is an invasive, traumatic and offensive experience for anyone. The fact that black citizens experience this that such a high rate is IN ITSELF a huge indicator of racial inequity. 

    1. Unreasonable is the key word

      Unreasonable is the key word in your comment as well as the law but does not serve your conclusion. One would need evidence that the searches were unreasonable across the board to determine that there was racial inequity.

    2. Flawed logic

      Hi Karen,

      There are two key problems with your analysis.

      1. You assume that all consent searches by Evanston police are unreasonable. That is proved false by the the fact that contraband is found in consent searches by police at a high rate in Evanston — a higher rate that the statewide average. Some — though not necessarily all — of the searches clearly appear to have been reasonable.

      2. On the other hand, you assume that searches would be equitable if searches of all racial groups were conducted at an identical rate based on their share of the population. Given that all available data suggests criminal behavior is not distributed equally across racial groups, that practice would likely result in a far higher total number of unreasonable searches than the current practice.

      Now, Evanston could conduct an experiment to test dramatically reducing, or dramatically increasing, consent searches — so as to achieve racial parity in the searches.

      Likely results: A radical decrease in the total number of consent searches would result in far fewer guns being taken off the street. A radical increase in searches would result in a far larger percentage of searches turning up nothing.

      However, I think the data does suggest that a modest increase in the rate of consent searches of white motorists might improve the overall contraband yield rate — assuming police had a clear justification for conducting those additional searches.

      — Bill

Leave a comment
The goal of our comment policy is to make the comments section a vibrant yet civil space. Treat each other with respect — even the people you disagree with. Whenever possible, provide links to credible documentary evidence to back up your factual claims.

Your email address will not be published. Required fields are marked *