Brown is taller than Officer Wilson. The trajectory shows that Brown was shot first upward in the arms (with the arms in a raised position) then downward in the chest (as he falls below officer Wilson) then his parallel to the ground in the head as he continues to fall.
https://www.youtube.com/watch?v=tWUkBxmFUvU
https://www.youtube.com/watch?v=tWUkBxmFUvU