[joeysteele]

An example of 100% certain case was the murder of Lee Rigby, the guy was talking about why he had done it with Lee's blood on his knife.
A woman had even gone to try to reason with him as to why.

No doubt there at all in that one as to the murder of Lee and who had carried it out too.

That kind of certainty would have to be the criteria for any death penalty and they would probably be very few and far between.
There however was a 100% certainty as to a murder and murderer.