Jason Van Dyke: Chicago police officer found guilty of murder after fatal shooting of black teenager Laquan McDonald

'Justice for Laquan! Justice for Laquan!' demonstrators chanted in Chicago following the verdict's announcement

McDonald was killed in 2014. He was 17-years-old (AP)

Chicago police officer Jason Van Dyke has been found guilty of second degree murder and multiple accounts of aggravated battery by a jury over the shooting of 17-year-old Laquan McDonald in 2014.

Van Dyke's had originally been on trial for first degree murder for the shooting, marking the first time since 1980 that a Chicago police officer had stood trial for that crime.

In anticipation of the verdict, protesters in the city had already begun taking to the streets in downtown Chicago, and police advised food carts to leave Daley Plaza in case demonstrators grew violent. Some schools had indicated they were considering sending students home early if the verdict was announced during classes, and the Chicago Police Department said in a statement that it had "a comprehensive operating plan to ensure public safety in all of our neighbourhoods while simultaneously protecting the rights of peaceful demonstrations".

"Justice for Laquan! Justice for Laquan!” demonstrators chanted on Friday as they marched following the verdict's announcement, according to the Chicago Tribune.

Van Dyke now faces 15 years in prison, with the possibility of parole. His bail was revoked on Friday after he was found guilty.

McDonald was just 17-years-old when he was shot 16 times by Van Dyke in an attack that was caught on camera. Footage of the shooting sparked a firestorm of protests in Chicago and around the country, adding another name to the long list of black men killed by police officers in America.

(REUTERS (REUTERS)

In the video, which was not released until November 2015, McDonald can be seen walking down the middle of a Chicago street when police show up. Van Dyke exits his vehicle as McDonald appears to begin walking towards the side of the road and away from the officers. Van Dyke, moments later, takes a step forward, then opens fire on McDonald. He shot the teenager, who reportedly had a knife in his possession, 16 times.

Assistant special prosecutor Jody Gleason, speaking to jurors before they were dismissed to contemplate the verdict, told the group that the video showed Van Dyke contemplating shooting McDonald before the officers even arrived at the scene. She said that the evidence showed Van Dyke did not shoot McDonald out of fear for personal safety — as is often the defence for police officers on trial for similar charges — but because he does not care for human life.

"You heard what it was that he said, 'I guess we'll have to shoot him,'" Ms Gleason told the jurors.

She continued: "It wasn't the knife in Laquan's hand that made the defendant kill him that night. It was his indifference to the value of Laquan's life."

The protests after the video came out were not isolated or in vain, and the shooting resulted in heavy criticism of the city's mayor for keeping the video out of public hands for over a year, a Justice Department investigation, and the eventual ouster of the Chicago Police Department's superintendent.