What actually happened on 9th August?
That is precisely what the grand jury has been trying to ascertain. In theory the proceedings are held in secret but we know a few things, including the fact that Officer Wilson testified in his own defence. Also heard was Dr Michael Baden, a former public coroner and high profile criminal expert, who carried out an autopsy on the victim on behalf of his family.
A protestor in Union Square reacts after the announcement not to indict Ferguson police officer Darren Wilson. Photo / AP
We know that Officer Wilson confronted Mr Brown and another man from the driving seat of his police cruiser telling them to stop walking down the middle of the street. Officer Wilson's version of events, it has been reported, is that the young man lunged at him through the window of the car causing a struggle. Other witnesses, however, have spoken of the officer exiting the car and shooting the teenager as he ran away and carried on firing as he turned and raised his hands in surrender.
What made this case blow up the way it did?
While this could have happened in any number of communities all across the United States, the death of Michael Brown struck a chord first, perhaps, because it happened on the eve of his going to college. He had no criminal record either, although Officer Wilson is said to have testified that he recognised the other man who was with him as having just participated in a corner shop hold-up just minutes away.
But this became a symbol of lingering racial tensions in the United States. The dead man was black and the officer is white. It thus also spoke to deep resentment in the African American community about a long and well documented history of abuse of minorities by some police departments for example in New Orleans, Chicago, Los Angeles and also New York.
Ferguson itself has meanwhile become a symbol of marginalisation of blacks. Once a prosperous suburb of St Louis in recent decades it has seen a second flight wave of middle class whites to more distant suburbs and the gap filled by mostly minority families, especially blacks. Nearly all the power in the community, however, has remained in white hands. At the time of the shooting the Ferguson police department had 50 white officers and three black officers.
What is 'hands up, don't shoot'?
It is the chant adopted by many of the protestors who converged on Ferguson during the August unrest that sought to crystalise fury over police abuse and the alleged circumstances of Mr Brown's killing. It is meant in effect to shame the police. In the weeks since a competing coalition has emerged to denounce the disorder in Ferguson and praise the police response. It's slogan: "Pants up, Don't Loot'.
Protestors hold signs during a demonstration in Times Square. Photo / AP
Who are the protesters?
While the August protests saw participation by a great number of residents of Ferguson and the surrounding communities, including St Louis itself, it soon became apparent that activists had also traveled from all over the United States to take part. The authorities sought to blame some of the violence, including looting and ransacking of local business entirely on people from outside Ferguson, although there wasn't clear evidence to back that up.
As the day has approached for the grand jury to unveil its decision in the case, it has been clear that groups from far and wide have been preparing to join the marches and protests that are certain to happen.
