Death penalty isn't just 3

The other reason that death penalty is not just punishment is simply taking criminal's life can't be enough punishment. If criminals can die very easily without any suffer, that's too light punishment for that criminals who committed the crime which is cruel enough to be sentenced death penalty. If we lock up them in prison untill they dies, they can dedicate their whole life to regret what they did. But, death penalty kill them with out any time for regret what they've done, so it isn't just.

Death penalty as a punishnebt might not be enough. Criminals sentence to life impronment after doing a heinous crime is an unreasonable punishment for their victim and for the victim's family. If they will be locked in jail for the rest of their lives they may have time to feel sorry and their conscience will bother them until they die. But if it will be death penalty it will be just a one time punishment and they will not suffer for a long time.