Back to red light cameras, around where I live, they take two flash pictures if you violate. The first is to show you behind the stop line with the light red and the second is beyond the stop line (plus there's video). Obviously the first one does not mean a violation has occurred, just that it thinks you might violate. A picture of you beyond the stop line with the light red means nothing on its own hence the need for the before picture. It's almost impossible to make a legal right turn on red without getting the before picture taken.