Also overnight, word that Missouri Governor Jay Nixon has ordered the National Guard to restore order.
What started as a peaceful demonstration deteriorated as marchers pushed to one end of a street and police in riot gear attempted to push them back.
Police, in armored vehicles, launched tear gas and smoke canisters into the crowd. Even after a week of unrest, the scene was jarring.
"There were shootings, looting vandalism and other acts of violence. We had to act," said Capt. Ron Johnson, Missouri Highway Patrol.
Sunday was supposed to be a day of healing. Hundreds gathered a mega-church in St. Louis to remember Michael Brown, the unarmed black teen who was shot and killed by a white police officer just over a week ago.
In attendance, the slain teen's mother and the officer in charge of keeping the riots under control had a message.
"My heart goes out to you. I wear this uniform. I stand up here to say that I'm sorry," add Capt. Johnson.
Police have maintained that officer Darren Wilson was in some kind of altercation with brown before he fired his gun.
A preliminary autopsy ordered by Brown's family revealed that the 18-year-old was shot at least six times, including twice in the head. And it appears that the shots were not fired at close range.
Attorney General Eric Holder has ordered a federal medical examiner to perform another autopsy, citing a request by family members and the "extraordinary circumstances" surrounding the case.