An Oklahoma woman was reportedly beheaded Thursday at the food distribution plant where she worked. The FBI is now involved in the investigation, police officials confirmed Friday. The suspect is a former employee of the company, who reportedly tried to convert his former colleagues to Islam, but it is not known if his beliefs played a role in his suspected crime.

Alton Nolen, 30, had recently been fired from the Vaughan Foods distribution center. Nolen entered the building Thursday and began stabbing 54-year-old Colleen Hufford with a knife that may have been used at the distribution plant to cut lettuce and vegetables, said Sgt. Jeremy Lewis of the Moore Police Department. Nolen then “severed her head.”

The suspect turned his knife on former colleague and current employee of Vaughan Foods, 43-year-old Traci Johnson. A former CEO of the company and Oklahoma County reserve deputy, Mark Vaughan, arrived on scene and shot Nolen while he was attacking the woman. Nolen survived and is hospitalized; Johnson also survived and is in stable condition.

“There’s no doubt Vaughan saved Traci Johnson’s life. He’s, obviously, a hero in this situation,” Sgt. Lewis said. “It could have gotten a lot worse.”

Another employee in the building called 911 when she heard screams from down the hallway. The caller reported at least three gunshots, according to the 911 tapes. Police said it was not an active shooter situation.

Vaughan Foods released a statement Friday that said the company was “working with authorities on this active investigation and ask that you direct your questions to local law enforcement.”

Nolen was convicted of assaulting an officer and drug-related charges in 2011, according to Oklahoma State court documents. He had also recently converted to Islam, police said. Leaders of the Islamic Society of Greater Oklahoma City have been on high alert for heightened anti-Muslim sentiment in the community following the news, the organization’s spokesman Saad Mohammad told Oklahoma news website NewsOK.

“They have this ISIS [Islamic State group] thing on their minds, and now this guy has brought it to America,” Mohammad said.

ISIS, a Sunni militant group that recently seized portions of Iraq and Syria, released at least three videos in the past two months brandishing the beheadings of two U.S. journalists and one British  aid worker. On Wednesday, a militant group in Algeria by the name of Jund al-Khilafah reportedly beheaded a French journalist and pledged allegiance to ISIS.

According to NewsOK, a woman thought to be Nolen's sister posted this on Facebook: “He is alive and doing well. Thanks to all praying warriors out there friends and family. To god be the glory! My bro is alive and just know that the devil is a lie. Please continue prayers.”