SPRINGFIELD, Ill. (CBS) — The Illinois State Police have responded to accusations of bias from the American Civil Liberties Union of Illinois, but the ACLU is not satisfied.

As WBBM Newsradio 780’s Alex Degman reports, the ACLU has asked the U.S. Department of Justice to investigate six years’ worth of data the ACLU says proves state police officers are three times more likely to do a consent search of African-American-driven vehicles, and four times more likely for Latino-driven vehicles.

A consent search occurs when an officer wants to search a vehicle, but must ask permission to do so because there’s no probable cause.

In a written statement, the state police department says its troopers are actually less likely to stop a minority driver than other departments in the state. Harvey Grossman, legal director for ACLU Illinois, says that’s irrelevant because city and county departments do different things.

“There’s just no comparison between the functions they perform,” Grossmans said. “That data would only be relevant if they were policing the same area, and doing the same thing, which they’re just not.”

The statement from state police says the percentage of minority drivers asked for consent to search has steadily decreased since 2005, but Grossman says that is not the figure at which the ACLU is looking.

He says data referenced by the ACLU outlines the rate at which minority drivers are searched. That means the frequency at which they’re stopped, not the total number of drivers who are stopped.

In addition to the claims about certain demographic groups being targeted, he ACLU also claims that almost all drivers – between 94 and 99 percent – consent to searches when asked by state police troopers, suggesting that they are coercive and not really voluntary.
The ACLU said earlier this month said state officials have known about the problem for some time. But Grossman says Gov. Pat Quinn will not do anything about the alleged discrimination, so the ACLU had to its case to the federal government.

It is unclear when, or if, the Department of Justice will take up the investigation.