He shot him in the arm several times from the front then he would have had to go around his back and shoot him from behind from a 2 foot or more distance.
If there are any sound recordings it should be easy to see if there is a delay between the front shots and the so called rear shots.
But his lawyers will say he was running away WITH HIS HANDS IN THE AIR. So how many bullets came from the front or back. His lawyers will confuse the jury about reasonable doubt - suggesting Michael Brown is on trial, when it is the cop, and doubt should set the cop free.