Read the grand jury testimony. The witness who said that Mike Brown was kneeling when he was shot in the head execution style changed her testimony three times while on the stand. She initially had told the FBI that Mike Brown was shot four times in the back after he was on the sidewalk prone. She then changed her story after she read that he was only shot in the front, not the back. The witness was completely unbelievable.
The blood spatter evidence reveals that Mike Brown was headed towards Darren Wilson even after he was shot. The spatter does not reveal how fast he was moving, but it contradicts some witnesses who said that he dropped to the ground almost immediately.
What Mike Brown did immediately before getting shot is relevant to whether or not Darren Wilson was liable. If Mike Brown had not done anything violent at all, and was headed towards DW, then DW could not shoot. But MB had tried to get DW's gun. (There was a gunshot wound to MB's hand between the index finger and thumb, and his blood was found on the gun and inside of the car.) A reasonable person would fear that a person who had already went for the gun would be trying to get the gun again if he's walking towards you AFTER YOU DREW YOUR GUN.