LINCOLN, Neb. (AP) — The Nebraska Crime Commission says Lincoln police officers stopped black motorists at a disproportionately higher rate than other motorists last year.

The commission report released last week says officers pulled over more than 54,000 motorists in 2014, and 10.2 percent of them were black drivers. Black residents account for 3.9 percent of the city’s population.

Eighty-two percent of Lincoln’s population is white, and white drivers were pulled over in 78.8 percent of the Lincoln Police Department’s stops last year.

Civil liberties and civil rights advocates say the report’s findings are troubling.

Lincoln Public Safety Director Tom Casady says he doesn’t think racial bias is behind the disparity but also says he doesn’t know why the disparity exists.