The following video (from Live Leak, h/t Josh M.) depicts an off-duty Brazilian police officer who happens to be captured on security cam as he suddenly finds himself confronted by an armed robber rushing past him from the scene of the crime.
In the video you can see the cop entering the scene from the right about 25 seconds into the clip, wearing a white shirt, the bad guy enters the pic fast from the left.
The cop goes to his right hip, retrieves his pistol, and the bad guy spins around and snap-fires his own. The result? Here you go:
Reports are that the cop did not survive the head shot.