A fatal blunder (or worse)

Loosely translated, there was a story in a recent Guardian which went as follows.

Once upon a time, in 2003, there was a very bad person. Into the trade of white slaves from Eastern Europe and white powders from a place even further east. He was thought to have been involved in a number of murders and to possess a number of firearms, but he had never been charged with a serious offence.

One day he was travelling in the back of a car going about its quite probably unlawful business on the public highway.

Then, without any warning, he was shot, with six shots resulting in four head wounds, by a policeman, following in an unmarked car. [Editor's note: this sounds unnecessarily violent, but perhaps this is simply one burst from an assault rifle, with the idea being to shoot to kill, to try to make sure that the victim has no opportunity to retaliate].

The story does not say whether any firearms were ever found in or near the car in which the now dead man was travelling.

In 2013, ten years later, we get around to ruling that the killing was unlawful.

In 2014, another year later, the CPS gets around to looking at the file. The policeman concerned has by now retired, beyond the reach of disciplinary action, presumably on a nice police pension. We know nothing about the fate of the senior officers involved. Have they gone onwards and upwards, like the senior officer involved in a fatal shooting in a train at Stockwell?

What on earth is going on? Why was the deed done? Why was there not some other way? What was the justification? Where are the protocols which govern the use of lethal force? Why is it taking so long to bring the matter to a decent conclusion?