May I say, the only reason we got rid of it in the first place was a poor decision by a poor jury.
Derrick Bentley was the last man hung in Britain - for something he didn't do. Fair enough it shows the flaws, but it was an AWFUL decision given the evidence.
He was accused of breaking & entering, and assissting in a murder if a policeman. However, at the time of the murder - he had already surrendered and was being arrested. He shouted "let him have it Chris" - most logic would point to him meaning "let him have the gun" (remember - he had mental difficulties) but the jury decided he meant "shoot him".
This DOES show flaws - however, these flaws are easily ironed out. If they have an obvious mental difficulty - they need to be imprisoned for life and treated. If there is any doubt (like there was with the "let him have it") it should not be carried forward.
However, someone like, for example, the Lockerbie bomber or Boxing day (or was it Xmas, cant remember) bomber should be killed - there is evidence for the jury to be sure beyond all doubt they did it, and it is a crime worthy far more than a spell in prison.
Your final idea is interesting, maybe they should.
But anyway, there are not more legal costs if you have a good judge and jury in the first place. It's all the same - surely the judge should be 100% when sentencing anyone?










And the cost to change a system which only needs tweaking, not re-writing, is a waste of money, when it is a non-problem. Again, murders are on the down, theft and "petty" crime is on the up. Re-offending has only recently rised, by a tiny amount, and that's mostly for petty crime or crime that would not result in the death penalty. Violent crime incl. murder, manslaughter and GBH only has a tiny percentage of re-offended which I think was 39%, and 39% of a tiny number of murderers isn't a lot.

