Chicago Mayor Rahm Emanuel announced at a press conference on Tuesday that he has asked for the resignation of Chicago Police Superintendent Garry McCarthy, whom he hired shortly after taking office in 2011. 

"I formally asked for Superintendent McCarthy's resignation," Emanuel said.

McCarthy has come under fire after a video tape of a white police officer shooting black teen Laquan McDonald 16 times was released to the public.

"Now is the time for fresh eyes and leadership," Emanuel said at the news conference.

Illinois Attorney General Lisa Madigan has asked the Department of Justice to step in and investigate if the Chicago police force practices violate any federal laws.

"The shocking death of Laquan McDonald is the latest tragedy in our city that highlights serious questions about the use of unlawful and excessive force by Chicago police officers and the lack of accountability for such abuse," Madigan said in a statement. "Trust in the Chicago Police Department is broken."

The request to U.S. Attorney Loretta Lynch asks the Civil Rights Division to examine the policy of the use of deadly force and whether or not a pattern of discrimination exists within the police department.

The officer accused of shooting McDonald, Jason Van Dyke, was charged with first-degree murder last week.  McDonald was armed with a knife and had taken PCP, according to prosecutors. Defense attorneys said that the shooting was justified because the officer felt threatened in the confrontation.