Source: Justice Department to investigate Chicago Police

CHICAGO, IL -- The U.S. Justice Department is expected to launch a wide-ranging investigation this week into the patterns and practices of the Chicago Police Department similar to recent probes of Baltimore and Ferguson, Missouri, after a white Chicago police officer shot a black teenager 16 times, a person familiar with the matter told The Associated Press on Sunday.

The person said that the Justice Department is expected to make the announcement of a civil rights investigation this week. The person was not authorized to discuss the investigation publicly because it has not yet been announced and only spoke the AP on condition of anonymity.

The civil rights probe comes as the police department and Mayor Rahm Emanuel are under intense over their handling of the October, 2014, death of 17-year-old Laquan McDonald. White officer Jason Van Dyke was charged with first-degree murder more than a year after the killing and just one day before the release of police dashboard camera video showing the officer firing 16 shots at the black teenager.

Since then, Emanuel forced Police Superintendent Garry McCarthy to resign and formed a task force to examine the department in an effort to calm the city and deal with the most serious crisis of his administration.

But the pressure on the mayor has not diminished. The calls for the mayor to resign - something he said he won't do - have grown louder from protesters in the city, including more than 200 people who shouted that he step down during a Sunday afternoon march in downtown Chicago. Protesters counted to 16 during the march, a number that has taken on a symbolic significance since the demonstrations began.

Emanuel initially said a federal civil rights investigation of Chicago police tactics would be "misguided" because the U.S. Attorney's office in Chicago was already investigating. But Emanuel later reversed course and said he would welcome the Justice Department's involvement in helping restore trust in the department - something that politicians including Democratic presidential candidate Hillary Clinton and Illinois Attorney General Lisa Madigan have called for.

On Friday, Chicago released hundreds of pages that show police officers initially reported a very different version of the encounter with McDonald than the video shows. That further angered activists and protesters, who were already accusing the city of covering up what really happened the night McDonald was killed.

Emanuel's office and the police department did not immediately respond to a request for comment on reports of a federal investigation.

The Justice Department in the last six years has opened more than 20 investigations of police departments. In March, the department released a scathing report of the Ferguson police force that found pervasive civil rights abuses, and in May, it reached a settlement with Cleveland police that called for sweeping improvements - including to that department's use of force policies. It opened an investigation of Baltimore police in May after demonstrations there turned violent in response to the death of a black man in police custody.

Civil right leader Rev. Jesse Jackson said he was pleased with the decision to investigate Chicago. Jackson said he hoped that the investigation would focus not only on the police department, but on Emanuel's office and the Cook County State's Attorney's office that he and others have criticized for taking so long to bring charges against Van Dyke.

"All three of them, the police, City Hall and the prosecutor's office are suspect," Jackson said. "We cannot trust them."