By Timothy M. Phelps

The U.S. Department of Justice will open a wide-ranging civil rights investigation into the Chicago Police Department after the release of a video showing a patrolman's fatal shooting of Laquan McDonald and police reports from the officers on the scene that conflict with that video.

A law enforcement official familiar with the coming investigation said the inquiry probably will be announced "in the next week" and will focus on officers' use of deadly force, including the system of oversight of police shootings, as well as training and community engagement.

Calls for a Justice Department investigation have been growing since the release of the video, which shows Officer Jason Van Dyke shooting McDonald 16 times as McDonald, carrying a small knife, walked away from officers on a commercial strip on South Pulaski Road in October 2014.

The department had claimed that McDonald pointed the knife at officers and had moved toward them in a threatening manner. Several officers at the scene also said in reports that McDonald presented a threat; some even said he seemed poised to attack after he had been shot and was on the ground.

The video, which prompted protests upon its release and led to the firing of police Supt. Garry McCarthy, undercuts those accounts.

Chicago Mayor Rahm Emanuel initially said he opposed an investigation, but abruptly changed course and said he would welcome federal intervention. In a statement Sunday, Emanuel spokesman Adam Collins echoed the mayor's comment about welcoming a federal investigation.

"We will let the Department of Justice address what action they will or will not choose to take," Collins said in the statement, "but as was made clear last week, we welcome the engagement of the Department of Justice as we work to restore trust in our police department and improve our system of police accountability."

At the same time, City Hall announced that it had fired Scott Ando, chief administrator of the Independent Police Review Authority, the civilian agency that investigates police use of excessive force, including shootings. The agency has long been a target of criticism, as was its predecessor, the Office of Professional Standards. Both were accused of failing to do meaningful investigations of police misconduct.

The investigation will be conducted by the Special Litigation Section of the Justice Department's Civil Rights Division. The unit has at least 15 attorneys who are dedicated to conducting such inquiries. They primarily use a 1994 law that followed the police beating of Rodney King in Los Angeles.

Since 2009, the Civil Rights Division has investigated almost two dozen police departments in cities such as New Orleans, Seattle, Baltimore and Ferguson, Mo. The investigations are typically called "pattern and practice" investigations from a federal law that bans "a pattern or practice of conduct by law enforcement officers" that deprives people of their constitutional rights. Investigations can take months, if not years, and often result in lengthy reports followed by negotiations of a consent decree that require systemic reforms overseen by independent monitors.

(Annie Sweeney, Steve Mills and Bill Ruthhart of the Chicago Tribune contributed to this report.)

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