Sign up for our COVID-19 newsletter to stay up-to-date on the latest coronavirus news throughout New York A grand jury in St. Louis, Missouri has declined to indict Darren Wilson, the white Ferguson police officer who shot and killed unarmed black teenager Michael Brown in August, reigniting violent demonstrations from months ago.St. Louis County prosecutor Robert McCulloch announced the decision, which was condemned by the 18-year-old man’s family and supporters. President Barack Obama called for peace, but police and protestors clashed moments after the announcement 9 p.m. Monday.“There was a full investigation,” McCulloch said of the grand jury’s review of 75 hours of testimony from 60 witnesses. “They determined that no probable cause exists.”Two black women, one black man, six white men and three white women comprised the grand jury. They spent three months weighing the evidence to render their decision.Ferguson, Mo. has been a city of unrest since the shooting, with mass protests and demonstrations; many resulting in violent clashes with military-outfitted police and riot squads as well as the state National Guard capturing headlines around the world.Brown’s slaying reignited passionate discussions about racial tension in the United States and fueled debate regarding press freedoms.McCulloch, Obama and Brown’s family urged protestors to use the incident as an opportunity for positive change and not an excuse for violence.“No matter what the grand jury decides, I do not want my son’s death to be in vain,” Obama said, quoting Brown’s father, which later issued a statement saying he was disappointed by the decision.Those calls for peace appeared to be ignored, as protestors were seen on TV news reports throwing tear gas canisters back at police after police tried to disperse the crowd, once it turned unruly.Local businesses in the area had boarded up their windows and several schools in the area had closed early for Thanksgiving break, according to published reports, in anticipation of the verdict. Missouri Gov. Jay Nixon declared a state of emergency and also activated the Missouri National Guard.He stood with St. Louis County Executive Charlie A. Dooley and St. Louis Mayor Francis G. Slay Monday evening prior to the grand jury’s decision, jointly calling for “peace, respect and restraint.”“No matter what is announced,” said Dooley, “people will be emotional. I want people to think with their heads, not with their emotions.”“What happened to Michael Brown has deeply divided us,” said Slay, adding a message to protestors. “We will protect your right to peacefully assemble and speak your mind. [But violence and destruction of property] will not be tolerated.“The world will be watching us.”The U.S. Department of Justice is currently conducting a civil investigation into the Ferguson Police Department. That probe is ongoing, but it is unclear when it will be completed.