The executive director of the Council on American-Islamic Relations-Oklahoma (CAIR) said he didn’t know where murder suspect Alton Alexander Nolen learned about Islam.

Adam Soltani said he didn’t know if Nolen was a member of an Oklahoma mosque. It’s also not clear how long ago Nolen converted, though officials and co-workers described it as recently.

Department of Corrections records show that as far back as 2013, Nolen had a chest tattoo reading “As-Salaamu Ataikum,” a misspelling of an Arabic phrase, which translates to “Peace be upon you.” He also has a chest tattoo of Jesus and arm tattoos of “RIP Lil Kris, Judah” and praying hands on his arms.

Sources close to the investigation said Nolen adopted the online persona of “Jah’Keem Yisreal,” a phrase that the Washington, D.C.-based Council on American-Islamic Relations leaders said has no meaning in the Arabic language. Muslim leaders said it was odd that someone proclaiming themselves as Muslim would adopt a name so close to Hebrew.

“I can’t imagine any Muslim taking a Hebrew name,” said Ibrahim Hooper, national communications director for CAIR.

Nolen’s purported Facebook page contains rants about the end of days and “the day of judgment” and contains a prominent photo of jihadists carrying rocket launchers and guns.

Nolen’s Facebook page claims he was at one point employed by Rockin’ T Livestock & Cattle in Kansas, but company owner Taylor Ohlde said he’d never heard of the 30-year-old before the incident in Moore that has captured national attention. He said Nolen’s claims that he worked there are false.

Nolen has an extensive criminal history, which includes incarceration for possession of marijuana, escaping from detention, assault and battery on a police officer, and possession of a controlled substance with intent to distribute cocaine.

“I’m literally sick to my stomach hearing this news,” Hooper said of the killing. “There would be no excuse or justification of any kind for this.”

Soltani said about 40,000 Muslims live in Oklahoma and the community is “heartbroken” by the news. Taking a life is among the “gravest of sins” in the Islamic faith, he said.

“Our faith condemns such acts,” he said. “There’s nothing in our faith that supports the taking of innocent life. It’s definitely not something he got from the faith teachings.”

He also said while members try to share their faith with others, “aggressively” trying to convert another goes against the teaching. He questioned where Nolen learned the tenants of Islam.

Soltani said Oklahoma Muslims are being vigilant in case those with anti-Muslim sentiments decide to retaliate.

“Of course we’re concerned,” he said of possible retaliation following Nolen’s actions. “Our communities are on alert to take more safety precautions.”

Vaughan Foods would not answer questions about how many employees work at their Moore facility, how long they have been located in Moore, how long Nolen worked there and why he was fired.