TheLadyEvenstar when a criminal is convicted of a crime in court the jury must base their verdict on the fact they believe the person to be guilty beyond reasonable doubt.
Therefore, when a murderer, or rapest, or paedophile, or similar is convicted it is absolutely certain that they have committed said crime. There are miscarriages of justice. Sally Clarke, Angela Cannings, Donna Anthony, who were all found guilty of murder beyond reasonable doubt.
So are you saying that you would rather they died than Huntley lived? Given Huntley killed innocent people, how does your argument that it is ok to kill the occasional innocent person in order to rid society of the guilty ones work?