UPDATE | Missouri governor outlines Ferguson preparations

WELDON SPRING, Mo. (AP) — Missouri Gov. Jay Nixon said today that law enforcement officials have been working around the clock to make sure residents and businesses are kept safe once prosecutors announce whether a suburban St. Louis police officer will face charges for fatally shooting 18-year-old Michael Brown.

A grand jury is expected to decide later this month whether to indict Ferguson Officer Darren Wilson, who is white, in the Aug. 9 death of Brown, who was black and unarmed.

Weeks of protests followed the shooting, and officials are trying to make sure things remain calm once the grand jury decision is announced. Nixon said looting and violence that marred mostly peaceful protests will not be tolerated.

"That ugliness was not representative of Missouri, and it cannot be repeated," he said.

Nixon said that once the decision is announced, the state highway patrol will work with St. Louis County and city police as one unified command. The National Guard will also be available if needed.

During the protests after the shooting, police donned riot gear and patrolled in armored vehicles, drawing widespread criticism and raising questions about a program that supplies surplus military equipment to local police departments.