FERGUSON, Missouri: Police have been brushing up on constitutional rights and stocking up on riot gear to prepare for a grand jury’s decision about whether to charge a white police officer who fatally shot a black 18-year-old in suburban St. Louis.

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 Darren 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.

In the meantime, law officers have adjusted their tactics for interacting more peacefully with protesters while also honing their procedures for quick, widespread arrests. They plan to have a large contingent of officers at the ready, but have been meeting with clergy, community leaders and students in hopes of building relationships that could ease tensions on the streets.

“I know there’s a lot of anxiety, there’s a lot of fear, anticipation” about that announcement, said Missouri State Highway Patrol Capt. Ron Johnson, who was put in charge of security in Ferguson in the days after Brown was killed and is now part of a coordinated command with local police. But “I have a lot of hope.”

Law enforcement officers expect to receive at least a day’s notice before a grand jury announcement. That should provide time for them to execute security plans but may also allow demonstrators to prepare.

“The moment I learn that there is, in fact, a non-indictment, then there’s going to be an organized protest,” said Eric Vickers, a black St. Louis attorney and civil rights activist.

Brown was unarmed when Wilson encountered him walking in the street with a friend. A scuffle ensued and Brown was shot multiple times. Witness accounts of what happened varied, with some people saying they saw Brown raise his hands as if in surrender.

Wilson told investigators he felt threatened while fighting with Brown from inside a police SUV, where an initial gunshot was fired, according to information provided to several news outlets by people described as familiar with the investigation, but otherwise not identified. After Brown fled the vehicle, Wilson said Brown turned around in threatening manner, prompting the officer to fire the fatal shots, according to those accounts of his testimony.