Updated 10/27/11 – 2:35 p.m.

CHICAGO (CBS) — The Chicago Police Department is under fire this morning from the American Civil Liberties Union for its handling of 911 calls.

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As CBS 2’s Susanna Song reports, the ACLU announced Thursday morning that it was filing a lawsuit in Cook County Circuit Court.

The agency claims that the methods Chicago Police use to respond to 911 calls have been discriminatory against minority neighborhoods. The ACLU alleges there is a higher number of 911 calls that go unanswered in neighborhoods where minorities live.

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The lawsuit focuses in particular on the West Side’s Austin neighborhood, where about 90 percent of the residents are African-American.

Working on behalf of the Central Austin Neighborhood Association, the ACLU cites a 2003 Illinois law that requires services to be provided in an equal way that does not negatively impact a minority group.

The ACLU says it does not believe the city has been responding unevenly to 911 calls intentionally. But regardless, the agency says, some neighborhoods have been under-served by Chicago Police.

The civil rights lawsuit contends that the Emanuel administration’s strategy of shifting officers from administrative duties to beat patrols has left some minority areas with delayed police responses.

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The ACLU and the Central Austin Neighborhood Association said police patrols have not been equitably distributed.

Emanuel acknowledged that he has shifted hundreds of officers from desk jobs to beat patrols since he took office, saying he’s deployed them to areas where the crimes are occurring.

In response to the ACLU lawsuit, the mayor said the task isn’t over.

“We have applied more resources to the areas that need them and we’re not done and we constantly take a fresh look and it’s not static. If it was static, I would have been stuck with the system we had on May 15. I didn’t accept the way the police officers were distributed,” Emanuel said.

He said the strategy also includes an earlier curfew to keep young people on the streets, crackdowns on illegal weapons and constant re-evaluations of police deployment and strategy.

“I’m not done – nor is Garry McCarthy, the superintendent of the Police Department, or Al Wysinger, the First Deputy of the Police Department – in looking to see if we need to put more officers where we have a crime happening.”

The lawsuit is not asking for any monetary damages, but instead is asking the City of Chicago to submit a plan to a judge on how it will change its current method to guarantee that all neighborhoods receive equal services.

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The Chicago Department of Law declined to respond to the lawsuit until after papers have been served.