The Chicago Police Department will allow independent evaluations of its stop-and-frisk procedures and increased public disclosure of the practice under an agreement announced Friday with the American Civil Liberties Union.

The agreement follows a March 2015 report from the ACLU that found Chicago officers disproportionately targeted blacks and other racial minorities in hundreds of thousands of stop, question and frisk encounters.

"This unprecedented agreement with the ACLU is a demonstration of CPD's commitment to fairness, respect, transparency," Chicago Police Superintendent Garry McCarthy said.

Under the agreement, former U.S. Magistrate Judge Arlander Keys will provide public reports twice a year on Chicago police investigatory stops and pat downs, looking at whether the city is meeting its legal requirements. It goes into effect immediately.

The ACLU report identified more than 250,000 Chicago stop-and-frisk encounters in which there were no arrests from May through August 2014. African-Americans accounted for nearly three-quarters of those stopped, even though they make up about a third of the city's population.

The ACLU did not file a lawsuit against the city. Instead, the parties said in a news release that it comes after months of negotiations between the city, the department and the ACLU that aimed to avoid expensive and time-consuming litigation.

"What we have done here is move past the litigation process and advanced directly to a collaborative process, to insure that stops on Chicago streets meet constitutional and legal standards."

The Chicago Police Department faces a separate private lawsuit filed in April and seeking class-action status. In that lawsuit filed in federal court, six African-American residents of Chicago claim the street stops have led to constitutional abuses, including unlawful searches and seizures as well as excessive force.

The city and department have agreed to collect additional data about investigatory stops. That includes officers' names and badge numbers, the race, ethnicity and gender of the person stopped, the reason for the stop, the location, date and time of the stop and other details.

That information will be given to the ACLU and Keys, who will oversee the agreement's implementation. The agreement also calls for more officer training to make sure stops are conducted only when necessary and pat downs are done only when legally justified.