American humanitarian Peter Kassig’s reported conversion to Islam is unlikely to move the Islamic State group to spare his life, experts say.

Kassig, whose parents say he changed his first name to Abdul-Rahman, was threatened with beheading in a video released Friday by the jihadi group that controls much of eastern Syria and northwestern Iraq.

The 26-year-old Iraq War veteran founded a relief organization before he was kidnapped in Syria in October 2013. He converted to Islam in captivity, his parents said over the weekend.

Kassig’s murder would be the fifth in a series by the militants, who since August have filmed themselves decapitating two U.S. journalists and two British aid workers, purportedly as revenge for their countries’ policies toward the group.

Islamic State group fighters have terrorized Muslim and non-Muslim residents alike in areas they control, offering some non-Muslims a choice between conversion or death and targeting Muslims from non-Sunni sects for particularly brutal treatment.

It’s unclear which denomination of Islam Kassig chose to join, but scholars who study jihadi groups say it’s unlikely the Islamic State group, formerly known as the Islamic State of Iraq and Syria or ISIS, will care.

“The so-called Islamic State has beheaded scores of fellow Muslims in Syria and Iraq with impunity and even crucified others,” says Fawaz Gerges, an expert on jihadi groups and professor at the London School of Economics and Political Science.

“Once the extremist organization declares a Muslim or a non-Muslim an enemy of Islam, an infidel, it sanctions his execution,” Gerges says. “To behead Abdul-Rahman (Peter) Kassig, the so-called Islamic State would either dispute the veracity of his conversion to Islam or claim he is an American spy.”

The Islamic State group, formerly an al-Qaida affiliate, was disowned by the international terror network’s leader in February. Gerges notes other jihadis such as Jordanian extremists Abu Muhammed al-Maqdsi and Abu Qatada “have already called on the so-called Islamic State to cease beheading civilians, including Westerners, but with no success.”

“I doubt it if Abu Bakr al-Baghdadi, chief of the so-called Islamic State, listens to fellow jihadis whom he considers softhearted and even cowards,” he says.

Yale University Islamic Studies professor Frank Griffel, also chair of the university’s Council on Middle East Studies, says there’s likely to be intense debate among jihadis if Kassig is killed.

Griffel says under Islamic law the life and freedom of Muslims are generally protected unless they commit a serious crime.

Our son worked and lived alongside Syrian Muslims before his capture & had come to admire & respect them greatly. pic.twitter.com/F1VfVkBqi4 — Kassig Family (@kassigfamily) October 6, 2014

“If Mr. Kassig is considered a spy or an agent secretly working for the U.S. or other enemies of the Islamic State, they will argue that he never truly converted but only pretended to do so,” Griffel says. “He would be considered a hypocrite, which in itself is not punishable, but it would deprive him of legal protections that Muslims enjoy. An accusation of spying, for instance, or treason could then lead to a death penalty.”

But Griffel says a mere accusation that Kassig made a phony conversion may not cut it with the international jihadi movement.

“All this, of course, relies on evidence, since everybody who confesses to be a Muslim enjoys legal protection,” he says. “This will definitely lead to controversy among jihadists if the Islamic State does not produce that evidence. But then again, they may not care much a they have already been condemned by major theorists of the jihadist movement, most importantly Abu Muhammad al-Maqdisi.”

Mohamed Elmenshawy, a political Islam expert at the Middle East Institute think tank, says there’s “no common agreement among militant jihadists" on a "code of reference" regarding killings or beheadings.

In Islamic teaching, Elmenshawy says, capital punishment as a criminal sentence does not distinguish between Muslims and non-Muslims.

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Nonetheless, he doubts the group would try to characterize the killing as a criminal sentence.

“I do not believe [the group] is trying to justify its actions; they just do it in order to terrorize locals with such behaviors,” he says.