Sir.prize - I believe that they are obliged to take any case beyond the very minor to the CPS once the evidence has been gathered. The CPS then give their opinionon what charges, (if any) are to be brought. Basically, anything beyond the gathering of evidence and investigation of the crime goes to them, so in the case of a violent death their involvment is madatory. So the police can't very well be accused of sensationalising it. The media definitely can however. The story was reported in such a way in most tabloids that it suggested that the average person cannot even defend themselves from their own deaths without being charged for assault or murder. This is so painfully untrue that it's downright irresponsible.
When this first hit the news and was discussed on AB there was not one person who had a basic unsderstanding of the law that thought ay charges would be brought. And so it has been proved. The problem is that the media stoke up fear in everyone, and so they believe that they're helpless to defend themselves. Then they lump completely different cases (Tony Martin) into the equation and try to claim that he was imprisoned for doing the same thing, when he quite profoundly wasn't. Thus you get a public who believe that justice favours the criminals and have no confidence in the system, when all they need to do is broaden their horizons a little and they would see that on the whole (and I'm not saying it's flawless) it works very logically, and completely against common public perception