ROME — In one of his strongest anti-death penalty stands to date, Pope Francis on Friday called it “unacceptable” for states to impose capital punishment because it brings no justice to victims of crime and foments revenge.

In the same breath, the pontiff also took a strong pro-life stance, calling for human life to be protected from the moment of conception until natural death.

The pope insisted that there’s no such thing as one method of applying capital punishment better than another, even if they “reduce the pain and agony of the condemned” because there’s no “human way of killing another person.”

The pope’s comments came as he welcomed a delegation of the International Commission against Death Penalty, headed by Spaniard Federico Mayor, to the Vatican.

Francis said that capital punishment is a frequent resort for totalitarian regimes and fanatic groups for the extermination of political dissidents, minorities, and those labeled as “dangerous” or perceived as threats to their power.

Referring to the current increase of Christian persecution, with extremist groups such as ISIS beheading and crucifying members of religious minorities, Francis said that “as in the first centuries, also today the Church suffers the application of this punishment to its modern martyrs.”

Although he believes that taking someone’s life in a self-defense situation is legitimate, Francis said that when death penalty is applied, people are killed not because they are a present danger, but because of harm they caused in the past.

“It’s applied to people whose ability to damage is not current, but which has already been neutralized,” Francis said. “[People] deprived of their freedom.”

The pope said he regarded the death penalty as inappropriate, however serious a convicted person’s crime might have been. “For the State of law, it represents a failure since it forces to kill in the name of justice,” he said, adding that human justice “is imperfect” and “can make mistakes,” and it deprives the criminal of the chance to make amends.

Quoting Russian Fëdor Dostoevskij’s “The Idiot”, the pontiff said that killing someone who has killed is a punishment incomparably larger than the crime.

“Murder by legal sentence is immeasurably more terrible than murder by brigands,” Francis said.

As he did last October, when meeting with members of the International Association of Criminal Law, Francis also condemned life imprisonment or sentences that deprive the criminal of the possibility of imagining a life after imprisonment, saying they’re “concealed death penalties,” because the guilty person is not only deprived of freedom, but of hope.

On Saturday, Francis is scheduled to visit a detention center in Naples during a one-day trip to the southern Italian city. At the detention center “Guiseppe Salvia,” he will be welcomed by more than 1,900 prisoners and have lunch with 90 of them, including some from a section that houses transsexual, gay, and HIV-positive detainees.

The death penalty is also expected to be part of Pope Francis’ social message when he visits the United States in late September, a trip that will include an address to a joint session of the US Congress.