The evidence considered by a grand jury in a months-long investigation has been released, following the announcement Monday that there would be no indictment for Ferguson police officer Darren Wilson in the August shooting death of unarmed teenager Michael Brown.

That evidence includes dozens of volumes of information and police documents, totaling many hundred pages, and is aptly described as a "mountain." (Find it all here.) The evidence contains many revelations, previously undisclosed, including Wilson's first-hand account of the shooting.

Here's what you need to know, what people are saying and the context to best understand it:

It's statistically rare for a grand jury to do what Ferguson's just did. FiveThirtyEight's Ben Casselman writes, "Grand juries nearly always decide to indict. Or at least, they nearly always do so in cases that don't involve police officers." (According to 2010 statistics, grand juries did not return indictments in only 11 of the 162,000 federal cases prosecuted that year.)

Coming Sunday: The Atlanta Journal Contsitution will explore the grand jury process in depth.

But most police shootings don't end with prosecutionsaccording to the Associated Press.

Darren Wilson said Michael Brown charged at him. In an interview with police on Aug. 10, Wilson said Brown had run away from him following a violent encounter at Wilson's police vehicle, which started with Wilson's request for Brown and his friend to get out of the road. After the two struggled -- Wilson told police that Brown "made contact" with him at least 10 times and landed at least two "solid blows" -- Brown began to run away. Wilson ordered him to stop, at which point Brown, in Wilson's words, "[L]ooked at me, made like a grunting noise and had the most intense, aggressive face I've ever seen on a person. When he looked at me, he then did like the hop ... you know, like people do to start running. And, he started running at me."

There are more contradictory eyewitness accounts. In the wake of Brown's death, several eyewitnesses came forward and spoke publicly. With some descrepancies, many of them told a roughly consistent story, that Brown appeared to run away from Wilson following a struggle at the police vehicle, that Wilson continued to fire on Brown as he fled and that Brown appeared to surrender before being killed. Additional eyewitness interviews conducted by police further complicate that version of events. One witness told police that Brown charged Wilson after fleeing, and was repeatedly shot at before finally falling dead. But another witness told police that Wilson shot at Brown as he ran, and that Brown turned and stumbled or came toward Wilson before falling dead.

Wilson said Brown reached under his shirt during his charge, though police have said Brown was unarmed.

Brown looked "like a demon" during the struggle, according to Wilson's Sept. 16 grand jury testimony. Wilson -- who is 6-foot-4 and 210 pounds -- said struggling with Brown was "like a five-year-old holding onto Hulk Hogan."

Wilson told the grand jury that it was the first time he'd fired his weapon on duty. He shot at Brown 12 times, hititng him at least six times. Brown died about 150 feet from the police vehicle.

There are photos of Wilson's injuries following the shooting. In his Aug. 10 interview, Wilson described the injuries as "some redness to my left jaw line then I had swollen right cheek and jaw. I had scratches on my back and neck, on my shoulders. I guess my shoulders up to my hairline was scratches and red marks." Per a medical report dated the same day as the shooting, Wilson's face was bruised.

Prosecutor Robert McCulloch focused on the reliability of physical evidence and the unreliability of eyewitness testimony. "Physical evidence does not look away as events unfold, nor does it block out or add to memory. Physical evidence remains constant and as such is a solid foundation upon which cases are built," he said before the indictment announcement. Further: The jurors "are the only people, the only people, who have heard and examined every witness and every piece of evidence."

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