In cases where the guilt of the individual is beyond doubt (there are a few of them), I think that they should be either used for medical research, or failing that organ donorship.

The fact that money is wasted on looking after him is an indefensible drain on the public purse.

Starving people to death?

Are these the people that don't want to eat? Many elderly patients have no drive to eat or drink - their brain is that gone. They are not suffering in food and drink bieng witheld, and in fact are far more agitated when they are forced to eat and drink.

I agree that the big flaw with capital punishment is cases where there is doubt. Capital punishment should be on the books, but only used in a select group of people.