Updated

The family of Oklahoma beheading suspect Alton Nolen has expressed shock at how the ex-con raised in a Christian home could have committed such a gruesome crime, but experts say he fits the profile of a growing number of jihadists forged in the crucible of America's prison system.

Nolen, a Muslim convert with a lengthy rap sheet, is accused of beheading Colleen Hufford, 54, and stabbing another former co-worker at a Moore, Okla., food processing plant on Sept. 25. He reportedly shouted Koranic phrases as he carried out the savagery, which was stopped when Vaughan Foods Chief Operating Officer Mark Vaughan shot him. The attack has sparked controversy about whether Nolen, 30, is a “lone wolf” terrorist or simply a violence-prone criminal inspired by Middle Eastern radicals.

[pullquote]

Experts say there’s little meaningful difference, and that America’s prisons are full of prime targets for radicalization by increasingly sophisticated terrorist groups.

“[Nolen] fits the profile of an individual with emotional instability, predisposed to violence and introduced to Islam in prison,” said Patrick Dunleavy, former deputy inspector general of the New York State Police Criminal Intelligence Unit and author of the 2011 book “The Fertile Soil of Jihad: Terrorism’s Prison Connection.”

“He comes out, tries to assimilate with a local mosque, is spurred on by videos and Internet postings by groups like ISIS, and then the incident at his workplace — a perceived wrong against him — becomes the catalyst that trips the trigger in his mind to move from jihadi thoughts to violent action,” Dunleavy added.

Nolen grew up attending a non-denominational Christian church in Idabel, Okla. While family members interviewed by several outlets do not appear to have a consensus about when he converted to Islam — one cousin said it happened earlier this year after he was released — prison records show he had a tattoo on his abdomen bearing the Muslim greeting “As-Salaamu Alaikum,” or “Peace be upon you.”

"My son was raised up in a loving home," Joyce Nolen wrote of her son on her Facebook page. "My son was raised up believing in God. My son was a good kid. I know what they're saying he done, but I'm going to tell you this: That's not my son."

Nolen’s sister Megan expressed similar shock at how her “loving” brother could stand accused of such a monstrous act.

Oklahoma prison records show Nolen was freed after serving two years of a six-year sentence on charges that included assaulting a police officer and possession of cocaine with intent to distribute. Prior to that stint, he served time on drug charges. If his conversion to Islam happened while he served time, it would make Nolen one of thousands of American inmates who embrace the Muslim faith behind bars.

Experts say most practice the religion peacefully, but law enforcement warned as far back as 2006 that inmates were targets for introduction to the militant Wahabbi and Salfist strains of Islam, with then-FBI Director Robert Mueller telling a Senate committee that prisons were “fertile ground” for Islamic extremists. And Rep. Peter King, R-N.Y., told Fox News in 2012 that, while there’s “absolutely nothing wrong” with inmates converting to Islam, the process has a dark side.

“The problem is when you get radical Muslims,” King said. “You get radical chaplains who then radicalize them and turn them toward terrorism or turn them toward violence.”

A 2010 law enforcement bulletin from the FBI titled “Prisoner Radicalization,” describes a radical strain of Islam prevalent in prisons called Jam’iyyat Ul-Islam Is-Saheeh, which means “Assembly of Authentic Islam.” The interpretation, sometimes referred to as “Prison Islam,” supports the establishment of an Islamic caliphate, or government, in the United States and advocates the targeting of the American and Israeli governments, as well as Jews, in retaliation for their policies regarding Muslims, according to the FBI bulletin. For violence-prone men who find the tradition teachings of Islam or those of the Nation of Islam unfulfilling, a call to carnage in the name of faith can be alluring, according to the FBI.

“Prisons literally provide a captive audience of disaffected young men easily influenced by charismatic extremist leaders,” the FBI wrote.

Even if Nolen converted to Islam while in prison, his radicalization may have come later, or as part of a gradual process. In fact, his spiral, which reportedly included trying to convert co-workers, arguing for stoning women and condemnation of America, appears to track the rise over the last year of the Middle Eastern terror group Islamic State. Law enforcement authorities have said Nolen viewed the group’s grisly videotapes showing the beheadings of American journalists James Foley and Steven Sotloff, and his Facebook page included a picture of a beheaded victim.

“These images and social media messages are extremely powerful,” said Dunleavy. “In the past, we thought of terror groups in terms of cells, or handlers who coordinated attacks. But they no longer need handlers in direct contact to bring the crazy guy along and convince him to do their will. They can do it online and unilaterally."

By inspiring violent inmates and ex-cons to attack on American soil, terror groups no longer need to plan or coordinate, said Ryan Mauro, a national security analyst and adjunct professor of Homeland Security at the nonprofit research institute Clarion Project.

“There is a false debate about whether this was an act of murder by someone who happened to have radical Islamic beliefs, or whether this was a radical Islamic terrorist attack,” Mauro said. “It can be both. He believed that that such violence qualifies as a jihad and chose a target, his former place of employment, that he wanted revenge upon.”

Mauro, who tracks the threat of Islamic extremism, said Nolen’s Facebook page, which has since been taken down, included a photo of a prominent Islamic State leader with a note referring to the terror group as his "brothers."

Arnett Gaston, a professor of criminology at University of Maryland and a former commanding officer at New York’s Rikers Island jail, said inmates who find faith while doing time have historically changed their lives for the good and been a positive influence in prisons. But Gaston acknowledged that terrorist groups are targeting young Muslim converts, and law enforcement must take the issue seriously.

“In my experience, faith is a positive force in corrections and this type of radicalization is a rare event,” Gaston said. “But it would be ridiculous for us to ignore it.”