Friday's protests began after the acquittal of Jason Stockley, a former St. Louis police officer, who had been charged with the fatal shooting of Anthony Lamar Smith after a vehicle chase in December 2011.
The activists turned their attention toward officers on the scene, reportedly injuring nine city police officers and one State Highway Patrol officer.
"I am committed to upholding the constitutional rights of all Missourians, including the fundamental rights of peaceful protesters to engage in free speech and peaceable assembly".
"Violence and vandalism is not protest, it is a crime", Greitens said.
Fans who purchased tickets through Ticketmaster will receive an automatic refund to the credit card that was used for the purchase.
The band doesn't want to risk anyone's public safety by having the concert, and so things are off, at least for tonight.
As they left Saturday's meeting in Heman Park in the suburb of University City, protesters said they were heading to a mall, but they didn't specify which.
The band and Live Nation said in a statement that police had said law enforcement was not in a position to provide the usual protection for the audience under the circumstances. "But this is a protest that addresses injustices not only happening here in St. Louis but around the country". Stockley was charged with first-degree murder and armed criminal action in the shooting.
But dash cam video appeared to capture Stockley saying that he was "going to kill this motherfucker, don't you know it" during the pursuit.
O'Toole said the character of the demonstrations changed after darkness fell Friday, and the "agitators" outnumbered the peaceful demonstrators.
However, Wilson ruled that based on "nearly thirty years on the bench ... an urban heroin dealer not in possession of a firearm would be an anomaly", concluding that Smith had been the owner of the firearm, and referencing the drug found in Smith's auto. "I say I ain't got no justice, I could never be at peace", she said.
On Saturday evening, police were out in force as demonstrators rallied in St Louis.