A protester who advocated for peaceful demonstrations in Ferguson was charged Saturday with setting fire to a convenience store in a neighboring suburb.

A St. Louis County jail official said Joshua Williams, 19, of St. Louis, was being held on $30,000 bond. He is charged with arson, second-degree burglary and stealing less than $500.

Williams, who was frequently quoted and photographed protesting Michael Brown's death, is accused of using lighter fluid to set multiple fires inside and outside a QuikTrip in Berkeley. Court records said Williams confessed in a videotaped interview, and that his actions were captured by surveillance video and by news media.

The QuikTrip was looted after a white Berkeley police officer shot and killed Antonio Martin, a black 18-year-old, late Tuesday at a nearby gas station. Separate surveillance footage appeared to show that before the shooting, Martin pulled a gun on the unidentified 34-year-old officer.

St. Louis County police spokesman Shawn McGuire said it wasn't immediately known if Williams had an attorney. Williams didn't immediately return a phone message.

Williams has been arrested at least twice during Ferguson-related protests for unlawful assembly as well as refusal to disperse.

An MSNBC profile of Williams in September quoted him as saying, "We have to come together as one and show them we can be peaceful, that we can do this. If not, they're going to just want us to act up so they can pull out their toys on us again."

During a Ferguson Commission meeting earlier this month, Williams said black people should be able to walk into stores without being followed around like thieves.

"When the police go out there in their uniforms, they don't see nothing but thugs," he said. "All they see is targets in the streets."