It's a point not worth making. Justice comes way before saving taxpayer money by avoiding court cases via short-cuts. It was appropriate to shoot to kill in this case, as far as I can see. I suppose he could been incapacitated instead, but I wouldn't have wanted to be in the position to make that judgement and I'm not making it in hindsight. Generally, justice is served better by holding perpetrators to account via judicial process. Money doesn't come into it. Yes he might conceivably killed more people had he not been taken out. The fact that he wasn't given the opportunity did indeed save the NHS money, but that is a completely cockeyed way of looking at it. He was stopped from ruining even more people's lives. That's all there is to it, really.