BBC:

Romano Prodi, the leader of the current centre-left coalition, said Italy will lobby actively at the United Nations for an end to capital punishment worldwide. The Italian ambassador to the UN has already called upon the General Assembly to re-examine a document already presented for debate last month. Italy took up one of the ten non-permanent seats on the Security Council this week.

Mr. Prodi said at the weekend that no crime can justify one person killing another. This is a principle which all civilisations and religions share, he said.

Judaism:

Whoever sheds the blood of
by man shall his blood be shed;
for in the image of God
has God made man. (Gensis 9:6)

If anyone takes the life of a human being, he must be put to death. (Leviticus 24:17)

Christianity:

[Pilate, to Jesus:] "Don't you realize I have power either to free you or to crucify you?" Jesus answered, "You would have no power over me if it were not given to you from above." (John 19:10-11)

[The ruler in government is] God's servant to do you good. But if you do wrong, be afraid, for he does not bear the sword for nothing. (Romans 13:4)

Buddhism:

There is disagreement among Buddhists as to whether or not Buddhism forbids the death penalty. The first of the Five Precepts (Panca-sila) is to abstain from destruction of life....

However, as is often the case with the interpretation of scripture, there is dispute on this matter... Thailand, where Buddhism is the official religion, practices the death penalty, as do many other countries where the majority of the population are Buddhist, such as Sri Lanka, Japan, Korea and Taiwan. Moreover, almost throughout history, countries where Buddhism has been the official religion (which have included most of the Far East and Indochina) have practiced the death penalty. [wikipedia]

Hinduism:

There is no official Hindu line on capital punishment. However, Hinduism opposes killing, violence and revenge, in line with the principle of ahimsa (non-violence). India still retains the death penalty... [BBC]

Bahai:

The availability of the death penalty as an option in the judicial punishment of wilful murder is the symbol of a commitment. Paradoxically, it constitutes for everyone trustworthy evidence of the enduring value that society places on innocent human life. It is no doubt for this reason that capital punishment has been endorsed by those great religious systems whose primary mission has been the awakening of humanity's capacity for love and mercy. That it can be abused by evil or careless men in no way detracts from the essential role it plays in the moral order. [Baha'i letter to "Amnesty International explaining the Baha'i view of capital punishment", bold added]

Islam:

Life is sacred, according to Islam and most other world faiths. But how can one hold life sacred, yet still support capital punishment? The Qur'an answers, "...Take not life, which God has made sacred, except by way of justice and law. Thus does He command you, so that you may learn wisdom" (6:151). [About.com]

And regarding atheism, there is no official teaching as to what an atheist must believe, but certainly most of the "civilizations" we've seen which were officially founded on atheism (Communism) believed in and practiced capital punishment.

So where is Romano Pradi getting his teachings from?