The statistics are immaterial. Each victim is unique to their family, and if there is even one, then that is one too many. We rely on the police to be the first level of justice, and if they are not just, then there is no justice. The first problem they have is that they have been sold the line that the Law is just, and that's obviously not true: the Law needs to be applied with sound judgement, and it doesn't always happen. Taking the Law into their own hands because of a minor disagreement shortcircuits the provisions built into the Law to ensure common sense is brought to bear at the earliest opportunity, and that then results in what is happening. It means the fine sense of injustice I discussed above, when it takes a while for true justice to be found (which is the flip side of the old saw that justice delayed is justice denied), becomes a course sense of injustice when such obvious abuse as has happened - both in the US and in the UK, let me hasten to add, lest anyone think I am letting the UK police off the hook - is allowed to pass uncorrected.
Reducing injustic to a game of statistics is an inhummanly cruel twist of the knife, dismissing the value of a human life as irrelevent, a mere cipher. It is not whether you can quantify it, it's whether you should quantify it. It's irresponsible, and denies the blame for allowing it.