Evanston police are less likely to search a motorist's car during a traffic stop and more likely to find contraband when they do than the statewide average.
That's one finding of an Evanston Now analysis of data on police stops from 2012-2015, the most recent years available, maintained by the Illinois Department of Transportation.
On average Evanston police stop motorists for traffic violations 33 times a day. About five times a month they observe something during a traffic stop that leads them to ask the driver to consent to a search of the car -- either by a police officer or a police dog.
And about twice a month the search turns up contraband that leads to criminal charges -- for drug or gun possession or some other offense.
There are disparities by race and ethnicity in the frequencies of searches and the frequency of finding contraband both at the state and city level.
For searches that don't involve a police dog, Evanston police ask to search a white driver's car only about one-seventh as often as police do statewide. They ask to search a black driver's car one-third as often, and a Hispanic driver's car one fourth as often as police do statewide.
Police Chief Richard Eddington says Evanston police are "much more judicious" in requesting consent searches than is typical across the state, largely due to an agreement Mayor Elizabeth Tisdahl made in 2009 with the American Civil Liberties Union that required reasonable, articulable suspicion for a request for a consent search.
Evanston police also are more likely to find contraband in a driver's car, regardless of race, when they do a search than police are elsewhere in Illinois.
But with a much lower consent search rate, Evanston police overall are far less likely to recover contraband in a traffic stop than officers elsewhere. In only 0.04 percent of traffic stops in Evanston did a consent search turn up contraband, compared to 0.25 percent statewide.
Of course there may be differences in driver behavior in different parts of the state that affect those results.
Evanston police are dramatically less likely to call out a police dog to sniff for drugs when a car's driver is white than if the driver is black or Hispanic.
But they are also dramatically more likely to find contraband when they do a dog search of a white driver's car than the statewide average.
It's worth noting that the total number of non-dog consent searches in Evanston over the four year period was 152 and the total number of dog sniff searches was 90 -- creating a fairly small base for the racial comparisons.
Eddington says searches during traffic stops are based more "on what happens when you're up at the car than on who's in the car."
"If the officer smells an odor of burnt cannabis coming from the car, that car's probably going to get searched. If the driver appears to be impaired, you're going to search for open alcohol. So the observation is a precurser to a search, rather than who the driver is," he said.
"But who you are becomes more important as we engage in violence reduction activities, the chief said. "If we know you've been and continue to be an armed combatant in the ongoing conflicts in the City of Evanston, we'll look more closely to see if we can develop probable cause or reasonable suspicion for a search."
Jacquese T. Sims and the recovered gun (EPD photos)
Referring to the arrest last week of Jacquese Sims, the chief said, "The last traffic stop we made where we recovered a gun, when an officer walks up to a car and shines a flashlight through the window, the blue steel of a gun looks way different than the fabric of a floor mat. The officer can pick up that reflection and know what it is."
While the U.S. Census says that 61 percent of Evanston residents are white, the state traffic stop study assumes that the driving population here is only 52.5 percent white -- with more minority drivers entering Evanston from nearby communities.
The state figures show that minority drivers are stopped for traffic violations in Evanston at roughly the same rate as their share of the driving population. By contrast, statewide, minority drivers are about 25 percent more likely to be stopped that white drivers.
And white drivers are more likely than minority drivers in Evanston to be issued a traffic citation -- with black drivers the least likely to get one.
Drivers who don't receive a citation are generally issues a written or verbal warning.