A grand jury has reached a decision on whether to indict Darren Wilson, the 28-year-old Ferguson, Missouri, police officer who shot and killed 18-year-old Michael Brown in August. The highly anticipated decision was expected to be announced Monday, according to various media reports. It's unclear if Wilson will face charges in Brown's death.

The fatal police shooting more than three months ago triggered widespread protests over what many said was a history of police racism against Ferguson’s mostly black residents. The incident kicked off an investigation that centered on the question of whether Wilson shot Brown in self-defense. Prosecutors spent weeks compiling evidence, including autopsy reports and eyewitness accounts, before handing the evidence over to a grand jury for consideration. Many called for Wilson to be charged with murder for killing Brown, who was unarmed.  

The grand jury was tasked with deciding whether there was probable cause to believe Wilson committed a crime, a lower standard than proof beyond a reasonable doubt. Their job was not to decide Wilson’s guilt or innocence but rather if Wilson was protecting his own life when he killed Brown: Had the teen reached for Wilson’s gun? Had he threateningly charged the police officer?

Many of the facts of the case have come to light in the wake of the shooting; however, much of the evidence considered by the jury has been tightly sealed. “Despite countless newspaper articles, radio and TV broadcasts, and innumerable tweets and other social media posts, we do not have all of the facts,” Peter Joy, a law professor at Washington University in St. Louis, wrote. Some evidence might never be released.

Here’s a look at what we know for sure about the Michael Brown shooting. 

Darren Wilson shot and killed Michael Brown. A week after the shooting, Ferguson Police Chief Tom Jackson identified the police officer who killed Brown as six-year veteran officer Darren Wilson.

Brown was stopped for jaywalking. Despite subsequent reports that Brown was a suspect in an earlier convenience store robbery, Wilson did not know that at the time he approached Brown, Jackson indicated. Brown and his friend were stopped for crossing in the middle of the street. 

Brown was unarmed. St. Louis County Police Chief Jon Belmar confirmed in a news conference Sunday, Aug. 17, that Brown was not carrying a weapon at the time Wilson approached him. 

Wilson shot Brown six times. Multiple shell casings were found at the scene where Brown was killed. Brown’s body lay about 35 feet from Wilson’s squad car.

At least one shot was fired from inside Wilson’s squad car. Police have claimed that Brown and Wilson struggled inside his police car, but some witnesses reported that Brown was shot as he raised his hands in surrender.

Eyewitness accounts of the shooting differ. While all the accounts confirm that Brown first ran from Wilson before turning back, his reason for facing Wilson -- whether to surrender or attack -- was disputed.

Brown’s autopsy could support either story. Three autopsies were performed on Brown. One autopsy supposedly found gunshot residue on the teen’s hand, which would support the police officer’s claim that Brown had reached for his gun. However, another autopsy questioned that finding