Here is an example of evidence that supports the fact that Michael Brown was moving toward the officer:
GRAND JUROR: "So as far as physical evidence, we have the blood on the ground that was about 21 or 22 feet from where Michael Brown ended up." p 4741 of grand-jury-testimony.pdf source:
"Transcripts of the Grand Jury Proceedings
Here is a link to the transcript of the documents and evidence presented to the grand jury in Clayton, Mo., that was deciding whether to indict Officer Darren Wilson in the fatal shooting on August 9 of Michael Brown.
The documents were released by the St. Louis County prosecutor, Robert P. McCulloch.
— THE NEW YORK TIMES"
"Farther away from the car, the investigator showed with photographs, were two blood-spatter patterns – evidence showing that Mr. Brown was moving toward the officer, and the car, when he was killed in the second flurry of shots." - NYT: Documents Released in the Ferguson Case
See Witness 10 of Michael Brown Shooting