CATHOLIC CHURCH'S POSITION ON CAPITAL PUNISHMENT

As Catholics, we are bound to reflect on the necessity and justice of the use of capital punishment in our society and to take action promoting the just application of the moral law. The call for a death penalty moratorium in Missouri is an issue that has received increased legislative attention in recent years, and is one that the Missouri Catholic Conference (MCC), guided by the Gospel and Catholic social teaching--ESPECIALLY DIGNITY OF HUMAN LIFE, has reflected on, and thus is engaging an ongoing effort to obtain support for a moratorium on the death penalty.

With regard to capital punishment, The Catechism of the Catholic Church states:
The efforts of the state to curb the spread of behavior harmful to people’s rights and to the basic rules of civil society correspond to the requirement of safeguarding the common good. Legitimate public authority has the right and duty to inflict punishment proportionate to the gravity of the offense. When it is willingly accepted by the guilty party, it assumes the value of expiation. Punishment, then, in addition to defending public order and protecting people’s safety, has a medicinal purpose: as far as possible, it must contribute to the correction of the guilty party
Assuming that the guilty party’s identity and responsibility have been fully determined, the traditional teaching of the Church does not exclude recourse to the death penalty, if this is the only possible way of defending human lives against the unjust aggressor
If, however, non-lethal means are sufficient to defend and protect people’s safety from the aggressor, authority will limit itself to such means, as these are more in keeping with the concrete conditions of the common good and more in conformity with the dignity of the human person.
Today, in fact, as a consequence of the possibilities which the state has for effectively preventing crime, by rendering one who has committed an offense incapable of doing harm-without definitively taking away from him the possibility of redeeming himself-the cases in which the execution of the offender is an absolute necessity “are very rare, if not practically non-existent” (nn2266 and 2267).
US CATHOLIC bISHOPS HAVE SINCE THE 1980'S  TAKEN A STRONG STANCE AGIANST CAPITAL PUNISHMENT.