text: Church teaching now is that society has a right to protect itself, and that if the DP is necessary to that end it is allowed. If the DP is an effective deterrent it then it is allowed as it protects society from future harm. If the DP is not an effective deterrent then there is no justification under christian doctrine. Of course death would be a just sentence but that's an eye for an eye, not christian, which is to show mercy to those who have done evil.