The white Chicago police officer who shot black teenager Laquan McDonald 16 times in an encounter captured on dashcam video has been found guilty of second-degree murder, The Guardian reported.

After a second day of deliberation, the jury brought a verdict that eased anxieties about public disturbance in a city struggling to overcome racial tension between black communities and a predominantly white police force.

The verdict will be greeted as a measure of justice by the black community. As demonstrators gathered outside the court, listening to the verdict on cell phones, one woman said: “Thank you, Jesus.” There were cries of “Yes!”

But the verdict was inevitably divisive. Chris Southwood, the president of the Fraternal Order of Police, claimed the jury had been “duped” and said police had been “stabbed in the back” by “political operatives” in a “sham trial and shameful verdict”.

Police were put on 12-hour shifts to bolster available numbers by up to 4,000. However, officers will not be in riot gear, because the force is anxious not to send a message that they are ready for a fight, Supt Eddie Johnson told the Chicago Sun-Times.

The jury was instructed that first-degree murder would carry a sentence of 45 years to life. The sentence for second-degree murder ranged from probation to 20 years. Jason Van Dyke was also found guilty on 16 counts of aggravated battery with a firearm, which carries a mandatory minimum sentence of six years and a maximum of 30. He was found not guilty of official misconduct. He will be sentenced at a later date.