American Indian women in Minneapolis were stopped, searched and arrested at higher rates last year than any other demographic group, including black men, according to a new study from St. Catherine University.

And while, citywide, a majority of police stops were for traffic violations, American Indians were mostly stopped on the basis of being "suspicious persons," the report found.

"It definitely is going to have an impact on people's lives, when we think about family stability, income," Marina Gorsuch, an economics and political science professor at St. Kate's, said of the study's implications. "So even though we can't say why they're happening, this is a clear alarm bell of saying that this is happening."

The study's authors — Gorsuch, economics Prof. Deborah Rho, and student researcher Nicole Busker, senior economics and business administration major — said the disparities were the result of "a complicated interplay of underlying factors" and didn't necessarily indicate racial bias on the part of police.

Minneapolis police spokesman John Elder said department officials would need to look at their data and analysis in order to properly comment.

The report's conclusions were based on police stop and arrest data from November 2016 to October 2017 and figures from the American Community Survey. It will be released Tuesday by the Center for Indian Country Development at the Federal Reserve Bank of Minneapolis, which funded the research.

Compared to their share of the population, American Indian women were the most disproportionately pulled over or questioned by police, the report said. While they make up only 1.42 percent of the city's female population, American Indian women were disproportionately detained, representing 6.57 percent of all police stops of women, the report concluded.

"This equates to a ratio of 4.63, meaning that American Indian women were stopped by police 4.63 times as often as they would be if stops were proportional to their percentage of the female population in the city," the researchers said, adding that they were also five times more likely to get arrested and booked than white women. Most of the stops happened in the Midtown Phillips and East Phillips, particularly along the Lake Street corridor — which the study's authors suspected is tied to the area's higher rates of sex trafficking.

Perhaps more surprising is that they are stopped at a higher rate than black men, whose treatment by law enforcement nationwide has incited a debate about how police patrol minority communities. Nearly half of police stops of men are of blacks, who make up about 20 percent of the population, the report found, equaling a ratio of 2.55.

American Indians in general were also more likely than any other to be searched by police, the report found, appearing to back up earlier studies showing racial disparities in police practices.

In 2016, Minneapolis police started tracking the ethnicities and other demographic characteristics of drivers and pedestrians stopped by its officers, in response to an earlier American Civil Liberties Union report criticizing the department for disproportionately stopping black and American Indian residents.

In response, the department started training its officers to recognize their inherent biases and acknowledge law enforcement's history of hostility against minority communities.

Libor Jany • 612-673-4064