Protests spilled into the streets of Chicago Tuesday night, and more are expected, after the city was forced to release damning dash-cam footage showing a white police officer fatally unloading 16 shots into 17-year-old Laquan McDonald last year.Made public more than a year after the shooting, the video raised additional questions and outrage—not only about what the footage contained, but about why it took so long to see the light.\u0022Day by day, week by week, month by month, what happened here?\u0022 wrote Chicago Tribune columnist Eric Zorn on Wednesday. \u0022Who was pursuing justice and the truth and what were they doing? Who were they talking to? With whom were they meeting? What were they trying to figure out for 400 days?\u0022\u0022[W]ere they simply biding their time,\u0022 he continued, \u0022hoping the video would never be released and that this incident would simply fade from memory?\u0022\u0022It is graphic. It is violent. It is chilling,\u0022 Cook County State\u0026#039;s Attorney Anita Alvarez said in advance of the video\u0026#039;s court-ordered release. \u0022To watch a 17-year-old young man die in such a violent manner is deeply disturbing. I have absolutely no doubt that this video will tear at the hearts of all Chicagoans.\u0022As described by the Chicago Tribune:There is no sound on the controversial dash-cam video released late Tuesday afternoon by the city, only startling images that show a white Chicago police officer unloading 16 rounds on an African-American teen, who though armed with a small knife appeared to be trying to get away, police said. The video captures 15 seconds of shooting. For 13 seconds of it, McDonald is lying on the street.Two clouds of smokelike debris silently puff upward immediately after McDonald falls. His head appears to lift, his arm moves. Then more bullets. Another cloud of white debris kicks up from behind his head.And then it is over. The teen lies on the road for nearly a minute alone.The Chicago public school system deemed the video so disturbing that it sent pupils home with a letter to parents Tuesday saying counselors would be available, NBC Chicago reported.Shortly after the video\u0026#039;s release, protesters began marching through city streets. The Associated Press said\u0022[s]everal hundred people blocked traffic\u0022 near where the shooting took place, and some \u0022circled police cars in an intersection and chanted \u0026#039;16 shots\u0026#039;.\u0022In its different incarnations, the city-wide protest lasted for nine hours, into Wednesday morning. Putting the number of people arrested at five, NBC Chicago reported:There were many tense moments during the protests across the city.One man could be seen coming within inches of a Chicago police officer’s face, in a stare-down that lasted several minutes.At another point during the nine-hour march, crowds blocked the entrance to the Eisenhower Expressway, stopping traffic.Alvarez revealed Tuesday that her office learned of the video two weeks after the killing and has had a copy of the video since Nov. 4, 2014. According to the Huffington Post, \u0022[t]he disclosure prompted a new round of criticism over the 13-month delay in releasing the video and bringing charges.\u0022Chicago Police Officer Jason Van Dyke was charged Tuesday with first-degree murder and is being held without bail. Alvarez admitted that the prospect of the video going public forced her hand in bringing charges.Activists saw the delays by city officials in a cynical light.\u0022Superintendent [Garry] McCarthy knew about this tape a year ago, but he never said anything about it,\u0022 protester Tio Hardiman told the Chicago Tribune. \u0022The only reason they\u0026#039;re speaking up now is because the judge ordered the tape to be released. This is hypocritical.\u0022Or, as the Chicago Sun-Times wrote in its editorial published Wednesday:When justice is delayed — and failing to level with the public this long was justice delayed — it becomes justice denied. When justice is delayed, it smacks of politics when it finally arrives.Additional protests are expected on Wednesday and Friday.Meanwhile, the freelance journalist whose Freedom of Information Act request eventually forced the release of the dash-cam video in the first place says he was barred from attending a news conference with Mayor Rahm Emanuel and Superintendent McCarthy on Tuesday.