I have spent the last few hours reading each of these witness statements. I have a fairly clear picture of what happened.
There is no dispute that Brown attacked officer Wilson while he was seated in his patrol car. Shots were fired during the struggle, after which Brown ran away, officer Wilson in pursuit, weapon drawn, yelling at Brown to stop several times. At some distance, Brown stopped and turned towards officer Wilson. Brown made some motions with his hands, not raised in surrender, but more like to inspect them, and to look over his body for injury from the shot fired within the police vehicle. He was in fact grazed on the thumb at close range, most likely while grasping the gun itself. At this point he moved forward towards officer Wilson, hands near his ribcage. Wilson fired 3 shots at Brown, striking him. Brown stopped his approach briefly. He then continued his approach towards Wilson. Wilson fired several more shots, the last shot striking brown on the top of his head as he fell forward.
The grand jury considered a pile of evidence. Must have been some very difficult work slogging through all that.