In his sermon, a priest recently said he was against the death penalty. I do not like the death penalty either, but I am aware of reality.
Would you press a button that would save a million lives? The cost is that it would drop the A-bomb on Hiroshima and kill about 100,000 people.
Tic-Tac-Toe, Checkers, Mancala, and Chess are games of complete information. The player can see the whole state of the game. Poker, Monopoly, and life are games of incomplete information. The players do not know what their opponent or the environment are holding. In either case, the best strategy is to figure out what the best move the opponent could make and play against that. The less a player knows about the state, the more likely the player could choose the wrong move.
The priest said that sometimes an innocent prisoner could be killed. I think an innocent patient could die on the operating table. Would that risk stop all surgery? People are very careful to make medicine as safe as possible. One advantage of the death penalty is that the prisoner could repent, make a good confession, and go to heaven. That probably would not happen if they died in the middle of the crime.
The death penalty can keep bad people from killing again or motivate them to avoid killing in the first place. It can also keep good people good so they do not kill in revenge because they can be confident that the justice system will work and punish the criminal.
One problem with the death penalty is that prisoners spend ten or twenty years on death row as the legal system spins its wheels. The prisoner could have been reformed and is not the same person who committed the crime.
Should the death penalty policy be made to please the most advanced citizens or to control the worst citizens? We have the death penalty because we value life very much. Maybe in the past they had the death penalty because they did not value life highly. Will civilization ever advance so much that the death penalty is not considered?
Can you be in favor of the death penalty if you would not be the executioner?