Ahead of the verdict, the city had prepared for the possibility of the kind of massive protests that followed the release of the video in November 2015, with an extra 4,000 officers being put on the streets.
The shooting sparked a nationwide outcry.
The jury found him not guilty of official misconduct.
Judge Vincent Gaughan held a hearing Friday to consider revoking Van Dyke's bond.
For a man convicted with no previous criminal record, Mr. Greenberg said the mandatory minimum is his best guess for a sentence handed down on Van Dyke. The jury had eight men and four women, of those, seven were white, three Hispanic, one Asian-American and one African-American.
Image copyright Laquan McDonald Image caption Laquan McDonald was 17-years-old when he was shot and killed in October 2014 How did the shooting unfold? In the initial report, McDonald claimed the teen was acting erratically and charged towards him, causing the officer to fire 16 gunshots. It's possible that he was legitimately fearful when he shot the teen 16 times, as he and Laurence Miller-a Florida-based clinical psychologist-testified in the former police officer's defense. Chicago police are planning to ramp up their patrols, but that won't stop activists from holding peaceful demonstrations. He said it was a "sad day for law enforcement" because the verdict tells officers they can not do their jobs.
Mr Van Dyke was not among the first officers to arrive - the policeman who was on the scene first told prosecutors he saw no need to use force on Mr McDonald.More news: Elon Musk Mocks the SEC on Twitter: ‘Shortseller Enrichment Commission’
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This Oct. 5, 2018 photo provided by the Cook County Sheriff's Office in Chicago, Ill., shows Jason Van Dyke.
What happened at the trial?
Two alternative jurors who were dismissed from the trial on Thursday said they would have leaned toward finding the officer guilty of murder, according to the Chicago Tribune.
"[His] eyes were bugging out".
"I shot him", he said. I see his left shoulder start to come up.
Police spokesman Anthony Guglielmi said Friday that he could not go into specifics as to what the threats were. In recent years, fatal shootings of civilians by police officers in Cincinnati; Milwaukee; North Charleston, South Carolina; and the Minneapolis area have spurred intense protests, resulted in charges and ended with the officers acquitted or the juries deadlocked. Van Dyke approached the teenager who was carrying a knife but walking away from surrounding officers. Mayor Rahm Emanuel responded by firing Chigh Police Department Superintendent Garry McCarthy. A Justice Department investigation carried out in 2016 and 2017 found that the Chicago Police Department routinely used excessive force, often against the city's black and latino communities.
"This case has been about exaggerating the threat and trying to hide behind the police shield", prosecutor Jody Gleason said in her closing statement. Vic Mensa, who created the song "16 Shots" in dedication to McDonald's murder, also penned a message about the trial on Instagram.