The graphic video released shortly after officer Jason Van Dyke was charged with first-degree murder on Tuesday has also reignited impassioned debate about the use of force by law enforcement in the United States, with Chicago left dangerously on edge.
Protesters there have likened the Laquan McDonald killing to that of Michael Brown, the black teenager shot dead by a white policeman in Ferguson, Missouri last year, triggering 15 months of demonstrations in major US cities over perceived police brutality against black men.
But the dashcam video showed the 17-year-old walking away when Van Dyke opened fire and made no threatening gestures to justify the use of deadly force, prosecutors said in announcing the charges.
The case has been particularly painful for Edward Nance, who won a USD 350,000 civil judgment for injuries sustained when he was arrested by Van Dyke and his partner in 2007.
More From This Section
"It rocked him to the core," Nance's attorney, Michael McCready, told the Chicago Sun-Times.
Van Dyke was a member of the city's controversial and now-disbanded Tactical Response Unit which patrolled high-crime areas when he pulled Nance over because his car didn't have a front license plate.
Nance -- who worked at a cable company and as a high-school sports referee -- told investigators that Van Dyke's partner slammed his head on the hood of his car and that van Dyke violently handcuffed him and tossed him into a squad car.
The Independent Police Review Board dismissed the complaint because there were "no independent witnesses" and "no way to determine" the cause of Nance's injuries, the Sun-Times reported.
The 20 citizen complaints filed against Van Dyke since 2011 is below the average allegation rate, according to the Citizen Police Data Project from the University of Chicago.
However, he is still among the "small subset" of officers responsible for a "disproportionate" number of complaints.