The death penalty represents a failure

"For the rule of law, the death penalty represents a failure, as it obliges the state to kill in the name of justice. … Justice can never be wrought by killing a human being. … With the application of the death penalty, the convict is denied the possibility of to repent or make amends for the harm caused; the possibility of confession, by which a man expresses his inner conversion, and contrition, the gateway to atonement and expiation, to reach an encounter with God's merciful and healing justice."

Pope Francis