If I have to speculate, white shooters surrender and come out with their hands up. You literally said "while running away" in most places force, including lethal, is permitted to prevent fleeing criminals from escaping.

If you really want to talk about it, we have to dig up the rap sheets of those used in the studies to "prove" more jail time for the same crime. Is it their first offense? 3rd? What else have they been convicted for prior? I highly doubt two individuals of different race would receive different jail time if they had the same number of prior convictions. Unless you have an actual study that proves me wrong right now then you're speculating and not looking at the whole picture.