Riot police arrested two demonstrators in Ferguson, Mo., Thursday night as tensions simmered and protesters awaited the Michael Brown grand jury decision. (Reuters)

Missouri Gov. Jay Nixon declared a state of emergency on Monday and the FBI issued a bulletin warning of likely violence across the country as a St. Louis County grand jury concludes its investigation of Ferguson police officer Darren Wilson.

Nixon’s announcement, which allows him to mobilize the state’s National Guard to keep order, added to the overflowing docket of anxiety in greater St. Louis as the city braces for the expected news that Wilson will not be charged in the Aug. 9 fatal shooting of Michael Brown, 18.

The FBI bulletin, first reported by ABC News, warned law enforcement agencies that protesters are likely to attack police officers and federal agents after the decision. “The FBI assesses those infiltrating and exploiting otherwise legitimate public demonstrations with the intent to incite and engage in violence could be armed with bladed weapons or firearms, equipped with tactical gear/gas masks, or bulletproof vests to mitigate law enforcement measures,” the bulletin concluded.

Law enforcement officials have signaled that an announcement from the grand jury is likely at the end of this week or over the weekend. But a siege mentality has already taken hold again in this city that echoes the tense days after the shooting, when protesters clashed with riot police as the nation watched.

Ku Klux Klan leaders have handed out fliers in Ferguson that threaten “lethal force” against protesters, businesses have boarded up their storefronts, and local gun retailers say sales have skyrocketed. Law enforcement officials have warned of groups of “outside agitators” who could descend on the city after the announcement and incite violence.

Snow-covered military vehicles are parked behind a Missouri National Guard depot in St. Louis. The police in Ferguson, Mo., where Michael Brown was shot, will have no role in policing any protest in the city. (Tom Gannam/Reuters)
Declaration assailed

The imposition of a state of emergency, meant to ensure the safety of residents, immediately enraged protest leaders and some local black elected officials.

“The National Guard is called in when policing has failed,” tweeted St. Louis Alderman Antonio French. A “military presence in my city will mark a historic failure on the part of the [government].”

Local and national groups that hope to keep the response peaceful have been meeting for days to plan protest actions, while local churches have been collecting supplies and declaring themselves “safe spaces” in the event that protests are met with tear gas by police in riot gear.

Organizers have posted plans for actions in several cities across the country — Kansas City, Chicago, Atlanta and Washington — to take place in the hours and days after the grand jury decision is announced.

Nixon and local officials have stressed that the law enforcement response to any violence that breaks out in St. Louis will be directed by a “unified command” of city, county and state highway patrol officers. The Ferguson Police Department itself, however, will have no role in policing any protests.

The National Guard will be deployed to between 35 and 40 locations where the unified command has determined that, based on past protests and property destruction, it would be wise to have a “presence,” according to St. Louis Police Chief Sam Dotson.

“The National Guard is not coming to militarize the response,” Dotson said. “It’s a multiplier. It helps us protect our community.”

Missouri Gov. Jay Nixon swore in the members of an independent commission formed to investigate issues raised by the shooting death of unarmed 18-year-old Michael Brown in Ferguson. (Reuters)

“Regardless of the outcomes of the federal and state criminal investigations, there is the possibility of expanded unrest,” Nixon said in an executive order mobilizing the National Guard. “The state of Missouri will be prepared to appropriately respond to any reaction to these announcements.”

“This is America. People have the right to express views and grievances, but they do not have the right to put fellow citizens and property at risk,” Nixon said last week. “Violence will not be tolerated.”

Law enforcement officials are aiming to avoid a repeat of August, when the emotional initial response to the shooting included the burning of a local gas station and the looting of several businesses. In subsequent days, officers clad in full riot gear and driving large tactical vehicles deployed tear gas, pepper balls and rubber projectiles to disperse crowds numbering in the hundreds.

Nixon came under heavy scrutiny at the time after he waited more than a week before intervening. Eventually, he stripped authority from local police and granted it to the Missouri Highway Patrol. The violence subsided, but the protests have continued nonstop for three months.

The governor’s preemptive declaration of a state of emergency shows a lack of confidence in the ability of residents to remain peaceful, some protest and community leaders said. Others went further, arguing that the state of emergency amounted to a declaration of war against the Ferguson protesters, similar to what happened immediately after the shooting. Police were heavily criticized at the time for using tear gas and rubber bullets, taking sniper-like positions, and arresting journalists.

“Please understand the legal ramifications of a State of Emergency. Individual rights can be taken away,” tweeted state Sen. Maria Chappelle-Nadal, who represents Ferguson in the Missouri House. “This is his ‘head’s up.’ ”

‘People are afraid’

“These people are afraid,” said Steve King, the owner of Metro Shooting Supplies in nearby Bridgeton. King says his store typically sells 30 to 40 firearms a week. This week, it has sold 250. “One hundred percent of them are buying because of Ferguson.”

Businesses in Ferguson and, now, some in Clayton — where the prosecutor’s office and other county government buildings are located — have been boarded up as the protests have expanded from Ferguson to include much of the region.

On Monday, protesters took to a busy street in University City, an upscale business and social district in St. Louis, for a “die-in” in which they lay in the street and traced outlines of their bodies with chalk. On Tuesday, more than 100 marched the streets of Clayton demanding an indictment.

The demonstration, which took place as temperatures dipped into the low 20s, featured stagecraft with protesters organizing a troupe of “scared white people” who led the way, screaming theatrically, “Oh, no, hide! The protesters are coming!”

Following them were dozens of people who held signs and chanted, often pausing to shut down major intersections during the lunch hour.

Protesters were met with some cheers and honks of encouragement from motorists. Other motorists, however, attempted to force their way through the roadblocks — creating several tense moments as protesters stood in front of vehicles that attempted to push forward. Clayton police officers were on hand, but they largely kept their distance from the protests.

At one point, the marchers were met by a single Wilson supporter, who stood on a street corner holding a green sign that proclaimed:

“My family and friends support Officer Darren Wilson and the police.”

The woman, Patty Canter of Clayton, briefly engaged in a shouting match with some of the protesters, insisting that “all lives matter” and telling them that she believes Wilson’s account of the shooting — which has never been released publicly but has been leaked in part through various media outlets — will be vindicated once all the evidence is released.

While most Wilson supporters have avoided recent confrontation with the Ferguson protesters — instead rallying at private fundraisers that raised hundreds of thousands of dollars for the officer — Canter has been a frequent counter-protester and a presence at community meetings.

“When the facts are heard, I don’t think all of these protests will stand,” Canter said.

For now, she added: “I’m scared for my life.”

Sari Horwitz, Kimberly Kindy and Hunter Schwarz in Washington contributed to this report.