Authorities in the central U.S. state of Missouri are not the only ones worried about potential violence as the city of Ferguson awaits a grand jury decision in the fatal police shooting of teenager Michael Brown.
The Federal Bureau of Investigation said the announcement in the racially charged case "will likely be exploited by some individuals to justify threats and attacks against law enforcement and critical infrastructure." The agency issued the warning a few days ago in a bulletin obtained by news outlets.
A grand jury decision on whether to charge police officer Darren Wilson is expected this month. The August 9 shooting has already ignited racial tensions in the St. Louis suburb and spurred violence, as Brown was black and Wilson is white.
Missouri Governor Jay Nixon declared a state of emergency Monday ahead of the decision. The order authorizes the National Guard to be deployed. Officials said the troops will serve in a backup role to assist police.
Demonstrators gathered Monday in Clayton, Missouri, in anticipation of the grand jury's report. The grand jury has been hearing evidence there.
The FBI warned those looking to exploit public demonstrations could be armed. But it underscored its support for lawful protests, stressing "the importance of remaining aware of the protections afforded to all U.S. persons exercising their First Amendment rights."
The grand jury's decision on whether to indict Wilson has the potential to inspire public outbursts no matter which way it rules. But officials are particularly concerned that no indictment could trigger violence.
Brown was unarmed when Wilson shot him. The officer reportedly stopped the teen and a friend as they were walking in the middle of a street.
Witnesses said Brown had his arms raised in surrender and was shot multiple times even though he had run from Wilson.
But a review of the 18-year-old's official autopsy report found Brown may have been reaching for the officer's weapon as police officials have reported. It indicates Brown's wounds were consistent with Wilson's reported claim that he and Brown struggled inside his police car.