The Justice Department is expected to launch a wide-ranging investigation into the Chicago Police Department, following protests over the police killing of 17-year-old Laquan McDonald, who was shot 16 times by white police officer Jason Van Dyke more than a year ago. Dash cam video, only recently released by court order, clearly contradicts police claims about the shooting, showing the teenager posing no threat and walking away from the officers at a distance as Officer Van Dyke jumps out of his police car and opens fire. The controversy has ousted the Chicago police chief and led to growing calls for Mayor Rahm Emanuel’s resignation.