Sources say the much-anticipated verdict will likely be announced by a St. Louis County prosecutor at a press conference later on Monday.
FILE - In this Feb. 11, 2014 file image from video provided by the City of Ferguson, Mo., officer Darren Wilson attends a city council meeting in Ferguson. Police identified Wilson, 28, as the police officer who shot Michael Brown on Aug. 9, 2014 in the St. Louis suburb. The incident sparked racial unrest and numerous protests, including some that turned violent. (AP Photo/City of Ferguson, File)
The August 9 shooting, which some say was racially motivated, sparked riots and protests in the city of Ferguson. Missouri Gov. Jay Nixon declared a state of emergency last week in anticipation of the grand jury's decision, voicing concern that rioters would react violently.
CNN has more information on what the grand jury might announce:
Though the basic facts of the case -- that Brown was unarmed when Wilson shot him -- are not in question, the facts of the fatal moment are hotly disputed.
Supporters of Brown's family back witness accounts that Wilson fired while Brown had his hands up in surrender. Wilson's supporters say that Brown was the aggressor, had tried to take Wilson's gun while he was in his vehicle and that the officer fired in self-defense.
The 12-member grand jury is deciding whether Wilson should be charged with any of several possible crimes, including: first-degree murder, second-degree murder, voluntary manslaughter or involuntary manslaughter, said Ed Magee, a spokesman for the Prosecuting Attorney's Office.
The grand jury can issue an indictment on any of those four charges. It also can add a charge of armed criminal action, authorities said.
President Barack Obama last week urged protesters to remain peaceful, saying on ABC News: “This is a country that allows everybody to express their views, allows them to peacefully assemble, to protest actions that they think are unjust. But using any event as an excuse for violence is contrary to rule of law, contrary to who we are.”
This is a breaking news story. Updates will be added.