Defense attorneys claimed that Stockley believed Smith had a firearm; however, prosecutors alleged that Stockley planted the weapon. Although no charges have been filed against the protesters, a police spokesperson said they would be forthcoming.
Four officers have been injured and one police vehicle has been vandalized.
Violence that marred the mostly peaceful protests on Friday resulted in 11 police officers being injured and 33 people being arrested, officials said tonight.
After the verdict, about 600 protesters marched in downtown St. Louis, chanting "No justice, no peace" and "Hey hey!" The former police officer killed Anthony Lamar Smith in 2011 and was charged with murder previous year. When the accident came to a head, Stockley opened fire, shooting Smith five times. The officer quit the St. Louis Metropolitan Police Department in 2013 and was arrested in May 2016.
In a written statement, St. Louis Circuit Attorney Kim Gardner acknowledged the difficulty of winning police shooting cases but said prosecutors believe they "offered sufficient evidence that proved beyond a reasonable doubt" that Stockley meant to kill Smith.
Saturday's demonstrations were markedly calmer after almost three dozen people were arrested the day before, mostly for failure to disperse, resisting and interfering.
The revolver found at the scene only showed the officer's DNA.
Now six years and a not guilty verdict later, things in St. Louis are a big ole mess. Stockley and his partner tried to corner Smith in a fast-food restaurant parking lot after seeing what they said appeared to be a drug deal.
Singer Ed Sheeran and Irish rockers U2 cancelled concerts scheduled for Saturday and Sunday night in St Louis, citing security concerns. "As much as we regret having to cancel, we feel it is the only acceptable course of action in the current environment".
Fans who purchased tickets will receive a full refund, the band added.