The preparations are aimed at avoiding a renewed outbreak of violence during the potentially large demonstrations that could follow an announcement of whether Ferguson police officer Darren Wilson will face a criminal trial for the Aug. 9 death of Michael Brown.
Police and protesters have repeatedly clashed since the shooting, which prompted a national conversation about race and police tactics. Images of officers in riot gear and armored vehicles confronting protesters have drawn widespread criticism.
Many protesters want Wilson indicted for murder. Grand jury proceedings are secret, but legal analysts say recently leaked information about Wilson’s testimony to investigators may be an attempt to prepare the public for the possibility that he might not be charged.
The decision could be made public within the next month.