Chaldean Catholics (a non-Latin "rite" of Roman Catholicism) have condemned the death sentence for the murderer of their late archbishop.
From the mouth of their Auxiliary Bishop Shlemon Warduni:
“Monsignor Rahho, would not have accepted the sentence. Christian principles say it is not allowed to sentence someone to death, and instead it invites us to forgiveness, reconciliation and justice.”
Warduni is clearly wrong. One immediately recalls both the Old Testament law for Israel, which included the death penalty, as well as the historical practice of the Roman Catholic church for many years of advocating for the use of capital punishment (both in situtations in which we would deem proper, and in situations that we would deem improper). For those that need an example, consider the account of the trial of Giordino Bruno (link to Vatican's own reproduction of the account on the Vatican website)
For those who prefer Scripture, it is written:
Genesis 9:6 Whoso sheddeth man's blood, by man shall his blood be shed: for in the image of God made he man.
The death sentence for murderers is Biblical justice - and failure (by the king) to execute justice is not pleasing to God:
Deuteronomy 19:13 Thine eye shall not pity him, but thou shalt put away the guilt of innocent blood from Israel, that it may go well with thee.
Christians are called to personal forgiveness, but it is still the duty of government to put away the guilt of innocent blood from the land by executing God's justice on murderers. That has not changed in the New Testament. For that reason Paul writes that:
Romans 13:4 For he is the minister of God to thee for good. But if thou do that which is evil, be afraid; for he beareth not the sword in vain: for he is the minister of God, a revenger to execute wrath upon him that doeth evil.
May God have mercy on us, who deserve such justice from Him,
Thanks to Bill Cork of Oak Leaves for pointing out this article.