Oklahoma beheading suspect Alton Nolen reportedly told investigators he felt oppressed at work and resented not getting a raise. The 30-year-old man beheaded a woman and attacked another last week, police say, before being shot at Vaughan Foods in Moore, the food processing plant he was recently fired from. Nolen, who also went by Jah’Keem Yisreal, had troubles at work because of poor performance and for trying to convert co-workers to Islam, a law enforcement official told CNN.

On his Facebook account, Nolen had a number of messages related to Islam, and a cover photo of fighters holding a machine gun and rocket-propelled grenade launcher. But there was no indication of a link to terrorist groups, law enforcement officials told CNN on Monday. Nolen had also watched beheading videos, but it is unclear if they were related to the Islamic State group's murders.

A woman who identified herself as his mother defended him Sunday. "My son was raised up in a loving home," the woman who identified herself as his mother said in a Facebook posting. "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 Nolen, also posted a video on Facebook, saying this attack was out of character for him.

"Alton, my brother, he's always been a great person, a loving person," Megan said in the post. "He's always been a people's person, he's never been a violent person, so for something like this to have happened, we're all still in shock right now."

Nolen is expected to be charged Monday for last week’s attack at the plant. The man who shot him, Mark Vaughan, is the company CEO as well as a reserve deputy