(CNN) — Protesters took to the streets of Chicago late Tuesday after police released a graphic dash-cam video showing an officer shooting 17-year-old Laquan McDonald.
McDonald was killed in October 2014. The city's mayor has called for peace.
"I believe this is a moment that can build bridges of understanding rather than become a barrier of misunderstanding. I understand that the people will be upset and will want to protest when they see this video," Mayor Rahm Emanuel said. "We as a city must rise to this moment."