US man convicted of beheading co-worker

An Oklahoma man accused of beheading a co-worker was convicted of first-degree murder on Friday for the 2014 attack that one witness said was "something that people shouldn't have to see."

Jurors deliberated for about two hours before finding 33-year-old Alton Nolen guilty in the death of 54-year-old Coleen Hufford.

Jurors also convicted Nolen of assault and battery for attempting to behead a second co-worker at the Vaughan Foods plant in Oklahoma City.

Prosecutors have said they would seek the death penalty.

Investigators said Nolen had just been suspended from his job when he walked inside the company's administrative office and attacked Hufford.

Authorities said Nolen stabbed another co-worker, who survived. A company executive then shot Nolen.

Hufford's daughter, Kelli Hufford, released a written statement on behalf of the family, saying the verdict helps them move toward closure.

"This has been a long road for my family and me," the statement read.

"We are thankful the jury found Alton guilty of murder. All of us now hope for a swift sentencing process concluding with the death penalty for this killer."

During the trial, prosecutors played recordings of Nolen confessing to the stabbings while he was hospitalised following the attack.

In the recordings, Nolen says he doesn't "regret it at all" and that "oppressors don't need to be here."

Nolen's lawyers say he's mentally ill and that he believed he was doing the right thing because of his delusional misinterpretations of the Koran.

A witness who testified during the trial said Hufford was "completely surprised" when Nolen came up behind her, pulled her head back and drew the knife across her throat.