It was all triggered by disclosure of a horrific video showing what appears to be the cold-blooded murder by a police officer of 17-year-old African-American Laquan McDonald, who was shot 16 times. That video shocked the nation and led to the arrest of the police officer as well as a Justice Department investigation of the department.

For more than a year, the city fought to suppress that video, ensuring Emanuel's re-election could proceed without knowledge of what happened. A New York Times op-ed by former University of Chicago law professor Bernard Harcourt explicitly accused Emanuel and the city of deliberately covering up the video to help the mayor's re-election campaign, arguing that "the video of a police shooting like this in Chicago could have buried Mr. Emanuel's chances for re-election." Harcourt added, "These actions have impeded the criminal justice system and, in the process, Chicago's leaders allowed a first-degree murder suspect, now incarcerated pending bail, to remain free for over a year on the city's payroll."