Protesters form a line and walk holding signs that spell out "Laquan" following the release of a dash-cam video of 17-year-old Laquan McDonald being fatally shot 16 times by Chicago Police officer Jason Van Dyke, Nov. 24 2015, in Chicago. Chris Sweda/Chicago Tribune/Getty Images

Demonstrators confront police during a protest following the release of a video showing Chicago Police officer Jason Van Dyke shooting and killing Laquan McDonald, Nov. 24, 2015, in Chicago. Scott Olson/Getty Images

Demonstrators listen to speakers during protests in Chicago, Nov. 24, 2015, reacting to the release of a police video of the 2014 shooting of a black teenager, Laquan McDonald, by a white policeman, Jason Van Dyke. Jim Young/Reuters

Demonstrators march through downtown following the release of a video showing Chicago Police officer Jason Van Dyke shooting and killing Laquan McDonald, Nov. 24, 2015, in Chicago. Scott Olson/Getty Images

A protester shouts at Chicago police officers standing guard outside the District 1 Police headquarters in Chicago, Nov. 24, 2015. Frank Polich/Reuters

Demonstrators chant as the walk the streets during protests in Chicago, Nov. 24, 2015, reacting to the release of a police video of the 2014 shooting of a black teenager, Laquan McDonald, by a white policeman, Jason Van Dyke. Van Dyke was charged with murder in the incident. Jim Young/Reuters

Demonstrators form a chain near the Balboa bridge, Nov. 24, 2015, after city officials released the dash-cam video of Chicago police Officer Jason Van Dyke opening fire on 17-year-old Laquan McDonald, striking him 16 times, in October 2014. Armando L. Sanchez/Chicago Tribune/Getty Images

Protesters form a circle at the intersection of South State Street and West Roosevelt Road in Chicago following the release of a dash-cam video of 17-year-old Laquan McDonald being fatally shot 16 times by Chicago Police officer Jason Van Dyke, Nov. 24 2015. Armando L. Sanchez/Chicago Tribune/Getty Images

Authorities form a line to prevent protesters from entering an expressway, Nov. 24, 2015, in Chicago. Paul Beaty/AP Photo

A protester and a Illinois State Trooper exchange words while police form a line to prevent protesters from entering an expressway, Nov. 24, 2015, in Chicago. Paul Beaty/AP Photo

Chicago police form a line to prevent protesters from entering an expressway, Nov. 24, 2015, in Chicago. Paul Beaty/AP Photo

Protesters gesture near Chicago police while trying to enter an expressway, Nov. 24, 2015, in Chicago. Paul Beaty/AP Photo

Chicago Police form a line to keep a protest for 17-year-old Laquan McDonald from entering Grant Park, Nov. 25, 2015, in Chicago. Paul Beaty/AP Photo