A fired employee who had been trying to convert co-workers to Islam stabbed two female colleagues - beheading one of them - before an off-duty officer shot him, police have said.
Alton Alexander Nolen, a 30-year-old recent Muslim convert, was fired from Vaughan Foods, a food processing plant in Moore, Oklahoma on Thursday before returning to his SUV and smashing it into another vehicle.
He then climbed out and entered the building, attacking the first two people he saw with a knife, Moore Police Sergeant Jeremy Lewis said.
After beheading Colleen Hufford, 54, and stabbing Traci Johnson, 43, Nolen was shot and wounded by off-duty sheriff's deputy - and one-time company owner - Mark Vaughan.
Authorities applauded Vaughan, an Oklahoma County reserve deputy, for his quick-thinking. He owned Vaughan Foods until it was acquired by Reser's Foods in 2011 and now works as its Chief Operating Officer.
'This was not going to stop if he didn't stop it,' Lewis said. 'It could have gotten a lot worse.'
Nolen survived and was hospitalized. Johnson is in stable condition in hospital.
Lewis, who said he does not know why Nolen was fired, added that police are waiting until he was conscious before they decide how to charge him.
On Friday, Lewis said that Nolen had been trying to convert co-workers to Islam and that local police had contacted the FBI to help investigate the man's background, KFOR reported.
Co-workers said Nolen himself had only just converted to Islam, according to News9. It is not yet known if his beliefs played a role in the attack.
There were no immediate indications of a link to terrorism, officials said.
Records show Nolen has a long previous criminal record including assault and battery on an officer, possession of a controlled substance and possession of cocaine with the intent to distribute.
In 2010 he was charged with assault and battery of a police officer after being pulled over for having a fake license plate. He was discovered to be driving with a suspended license and when the officer tried to cuff him he pushed him hard in the chest and bolted.
According to Oklahoma State Court Records, there was 'a massive manhunt involving four law enforcement agencies, two helicopters... and lasted for over 12 hours.'
As part of his sentence – five years with all but the first two suspended – he was ordered to attend an anger management course.
He was last released from jail in March 2013, according to records.
Records also reveal he has a tattoo of Jesus on his chest and praying hands on his arm. He also has 'Assalamu Alaikum' - a greeting often used by Muslims meaning 'may peace be on you' - on his abdomen.
On Friday, 911 calls revealed the panic after he entered the building on Thursday afternoon.
'They're in the office, front office of the building. Yeah, we can hear a lot of screaming,' the caller tells the dispatcher.
'We don't know where the person went and he went through our front office, went through the shipping office and stabbed a woman in our customer service department.'
The suspect can be heard running and then three gun shots are heard, KFOR reported.Culled
'Stay down! Stay down!' the caller tells his fellow employees.
Lewis confirmed to KFOR that the type of knife he allegedly used in the attack was the same kind used at the plant. Nolen had worked as a production line employee.
He added that the suspect and the victims were apparently not involved with each other outside of their work at the business.
'The victims had no relationship to the suspect. He is just an angry employee that acted out,' Lewis said.
Police had been called to the store around 4.15pm following a report about a fight inside Vaughan Foods. While en route, officers were told that there had been a shooting, Lewis said.
'When officers arrived they approached the business as an active shooter situation. Once they entered the business they found a female deceased of stab wounds and they had a male with multiple gunshot wounds,' Lewis said.
He said the building was evacuated and searched and no other danger was found.
Employees returned to work on Friday.
'On behalf of everyone at Vaughan Foods, we are shocked and deeply saddened by the events of today,' the company said it a statement. 'Our thoughts and prayers go out to the families and friends of the team member we lost and all those affected.'
It added that it will provide support and counselling for those affected.