Hundreds of protesters gathered at a suburban St. Louis police station on Monday demanding murder charges against an officer who shot to death unarmed black teenager Michael Brown over the weekend.
The largely peaceful protests, monitored by about 50 police officers in riot gear, took place after a night of rioting when demonstrations over the death of Brown, 18, turned violent.
About two dozen businesses were damaged in the rioting overnight, 32 people were arrested, and two officers were injured, police said.
"It breaks my heart," Ferguson Police Chief Tom Jackson told reporters on Monday. "Last night was the worst night of my life."
The FBI is looking into any civil rights violations in the case, a spokeswoman for the agency said. St. Louis County police is leading the investigation into the shooting itself.
Jackson said there was plenty of physical evidence and eyewitness testimony in the case. "I really believe we can get to the truth of what happened here," he said.
Brown's family has asked for an end to the street violence, according to a statement obtained by KTVI television station. They have also hired lawyer Benjamin Crump, who represented the family of Trayvon Martin, a black Florida teenager who was also unarmed when he was shot in 2012, Crump's office said.
Monday's gathering appeared nonviolent, with protesters shouting "Stop the killer cops" and "No justice, no peace." Four people were arrested, according to KSDK-TV.
Unarmed teen shot to death
Police said Brown was shot on Saturday afternoon after a struggle over a gun in a police car. It was not immediately clear why Brown was in the car. At least one shot was fired during the struggle, and then the officer fired more shots before leaving the car.
The officer, who was not identified, is a six-year veteran and has been put on administrative leave, police said Sunday. The officer's race has not been disclosed.
Three of the Ferguson Police Department's 53 members are black, Jackson said. About two-thirds of Ferguson's population of about 21,000 are black, according to U.S. Census figures.
The first day of school in the nearby Jennings School District was canceled in the aftermath of the rioting.
More than 300 police officers, many in riot gear, tried to control the crowd on Sunday night, said St. Louis County Police spokesman Brian Schellman. The 32 people arrested will face charges that could include assault, larceny and burglary, he added.
Sunday's protests turned violent after dark, with rioters smashing windows of stores and restaurants and damaging cars.
Boon Chang, owner of Northland Chop Suey, was cleaning up glass on Monday morning after rioters smashed windows at his restaurant and stole sodas.
"If they saw a brick anywhere, they grabbed it," Chang said.
On a vacant building next door, someone had used red-orange paint to write: "The only good cop is a dead cop."
Brown's mother told KSDK that her son was a "good child getting ready to go to college" and was visiting his grandmother on the day the shooting took place.
The St. Louis County branch of the NAACP civil rights group called a meeting for 6 p.m. Monday to discuss the case, according to a spokesman for Murchison Tabernacle C.M.E Church, where the meeting will be held.