The Michigan State Police is continuing to explore what racial disparities may exist when officers pull people over.
An independent report released this week found evidence of racial disparities in traffic stops at about a third of agency posts surveyed.
Researchers with Michigan State University have been working with the state police to identify if race or ethnicity is a factor when officers stop drivers.
The research relies on a "veil of darkness" analysis that assumes it's more difficult for police officers to know a driver's race when it's dark outside.
The report suggests the agency’s stops conducted during daylight hours were more likely to involve African American and Hispanic drivers in 9 of 30 state police posts, including Lansing, Grand Rapids, Monroe and Flint.
But a press release notes that finding could be affected by “seasonal variation in traffic flow."
A more narrow analysis of stops before and after the switch to Daylight Savings Time found "African American and Hispanic drivers were no more likely to be involved in traffic stops in daylight compared to darkness."
The report cautions that more analysis is needed to confirm if there are other factors that could explain these disparities.
First Lieutenant Michael Shaw says the state police will explore if policy changes would help address any identified racial disparities.
“Right now, what our main goal is, is to find out if we do have disparities, and then figuring out, can we fix it or not?” Shaw said.
The ACLU of Michigan and the state police settled a lawsuit last year that alleged officers racially profiled a Black motorist. Part of that settlement involves a separate review from the firm CNA, which recently produced a report on East Lansing's police department, of the agency's approach to monitoring vehicle traffic.
Shaw says that review will also consider if state police policies or practices are contributing to racial disparities.
“That's why you kind of bring an independent person in there to take a look at it," Shaw said. "They can kind of determine where we're headed, if we need to change make some changes to the way that we conduct traffic patrol.”
He emphasizes these reports focus on disparities and not racial discrimination. He added future studies will also have access to GPS data for traffic stops to get a more complete analysis.