Chicago Police Department to undergo civil rights investigation
US attorney general Loretta Lynch has announced a federal civil rights investigation of the Chicago Police Department.
The investigation will search for patterns of unconstitutional policing practices throughout the police force.
The announcement comes nearly two weeks after the city released the video of a white Chicago police officer shooting a black teenager 16 times, killing him.
The investigation will be led by the Justice Department's civil rights division.
Its focus goes beyond the October 2014 shooting death of Laquan McDonald to look at the police force's policies on use of force, including racial, ethnic and other disparities, and its accountability systems.
The investigation is similar to ones recently undertaken in other cities, including Baltimore and Ferguson, Missouri.
A Justice Department investigation of the Cleveland police force ended earlier this year in a sweeping settlement.
A number of police killings over the past year have shaken several US cities and given rise to the nationwide Black Lives Matter protest movement.
Ms Lynch said: "We understand that the same systems that fail community members also fail conscientious officers by creating mistrust between law enforcement and the citizens they are sworn to serve and protect.
"This mistrust from members of the community makes it more difficult to gain help with investigations, to encourage victims and witnesses of crimes to speak up, and to fulfil the most basic responsibilities of public safety officials.
"And when suspicion and hostility is allowed to fester, it can erupt into unrest."
The Chicago Police Department and Mayor Rahm Emanuel are under intense scrutiny over their handling of the October 2014 death of the 17-year-old McDonald.
Officer Jason Van Dyke was charged with first-degree murder on November 24, more than a year after the killing and just hours before the release of police dashboard camera footage showing the officer shooting the teenager.
The video shows McDonald veering away from officers on a four-lane street when Van Dyke, seconds after exiting his squad car, opens fire from close range. The officer continues shooting after McDonald falls to the ground and is barely moving. The video does not include sound, which authorities have not explained.
Chicago City Council signed off on a 5 million US dollar settlement with McDonald's family even before the family filed a lawsuit, and city officials fought in court for months to keep the video from being released publicly.
The city's early efforts to suppress its release coincided with Mr Emanuel's re-election campaign, when the mayor was seeking African-American votes in a tight race.
Since the release of the video, Mr Emanuel forced Police Superintendent Garry McCarthy to resign and formed a task force to examine the police department. But the calls for the mayor to resign - something he said he will not do - have grown louder from protesters, including the voices of more than 200 people during a march on Sunday. Protesters counted to 16, in reference to the shots fired.
Mr Emanuel initially said a federal civil rights investigation of Chicago police tactics would be "misguided", but later reversed course and said he would welcome the Justice Department's involvement - something that politicians, including Democratic presidential candidate Hillary Clinton, have called for.
A spokesman for the Chicago police department referred a request for comment about the reported investigation to Adam Collins, a spokesman for the mayor's office.
"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," Mr Collins said.