Cast as an olive branch by some, the Ferguson police chief's attempt to march with protesters demanding charges in the killing of an unarmed, black 18-year-old by a white officer still erupted into a clash that activists Friday blamed on police missteps.

The trouble Thursday night came hours after Police Chief Tom Jackson released a videotaped apology to Michael Brown's family that drew skepticism from residents and protesters who still crave answers about Brown's death. A county grand jury is weighing whether to indict Ferguson officer Darren Wilson in the Aug. 9 shooting, and the Justice Department is investigating whether Brown's civil rights were violated.

The Justice Department, which is also conducting a broader investigation of the police department, on Friday urged Jackson to ban his officers from wearing bracelets supporting Wilson while on duty and from covering up their name plates with black tape.

Ferguson residents complained about the bracelets, which are black with "I am Darren Wilson" in white lettering, at a meeting with federal officials this week.

"There is no question that police departments can and should closely regulate officers' professional appearance and behavior, particularly where, as here, the expressive accessory itself is exacerbating an already tense atmosphere between law enforcement and residents in Ferguson," Christy E. Lopez, deputy chief of the special litigation section of the Justice Department's civil rights division, wrote in a letter released Friday. "These bracelets reinforce the very 'us versus them' mentality that many residents of Ferguson believe exists."

Lopez also noted that officers' covering of their name plates is a violation of the police department's own policy.

The unrest Thursday occurred two days after many in the St. Louis suburb complained police did little to douse a fire that destroyed a makeshift Brown memorial.

"You have people grasping for a crumb of justice," protester Charles Wade, 31, of Austin, Texas, said Friday near a canopy across the street from the police station where protesters have regularly gathered since shortly after Brown's death. "There's a circle of trauma that keeps happening."

He said Thursday night's protesters appeared largely unmoved by Jackson's apology, saying they "felt it was more of a PR move than sincere." In it, Jackson acknowledged Brown's body should have been removed from the street much sooner than the four hours it was there as police collected evidence.

He insisted officers meant no disrespect to the community or Brown's family. "I'm truly sorry for the loss of your son," Jackson said.

News also surfaced Thursday that the man hired to handle public relations for Ferguson, including the chief's apology, was fired after officials learned he had been convicted of reckless homicide in 2006 in a shooting in Shelby County, Tennessee. Devin James told the St. Louis Post-Dispatch the shooting was self-defense and he served 90 days in prison.

James and Jackson did not return messages to The Associated Press seeking comment.

Witnesses said Jackson agreed to join marchers Thursday but failed to tell officers monitoring his safety to stand down. They said that led to some officers forcing their way into the gathering, then pushing and shoving marchers. Several protesters were arrested.

"If (the officers) had just not come in, everything would be all right," protester Steven Wash, 26, of Ferguson, said Friday.

"Jackson decided to come out and broker some peace and pretty much asked what he could do to build a new level of trust, and police continued to come, come, come," Wade added. "The olive branch he tried to extend was great, and it showed he wasn't a robot. But police forced him out like he was a diplomat in a war zone."

Protesters with the group Lost Voices said two of their members were arrested Friday as Ferguson officers shut down a campsite that had been in a vacant restaurant's parking lot since soon after the Brown shooting.