PURCELL, Okla. (AP) -- A grocery store stocker was arraigned Monday on first-degree murder charges for the killing of a 10-year-old girl in what authorities described as an elaborate plan to eat human flesh.

Kevin Ray Underwood, 26, appeared in McClain County Courthouse before Judge Gary D. Barger. The judge entered a not guilty plea for Underwood and provided him with a court-appointed attorney.

Underwood was arrested Friday and held without bail after drawing suspicion at a checkpoint set up near the apartment complex where he and Jamie Rose Bolin were neighbors in this small town 40 miles south of Oklahoma City.

Authorities said he led investigators to his apartment, where they found the girl's body in a large Rubbermaid tub sealed with duct tape in his bedroom closet.

Authorities believe Underwood lured the 10-year-old into his apartment, beat her over the head with a wooden cutting board and suffocated her with his hands and duct tape.

Purcell Police Chief David Tompkins said investigators believe Underwood sexually assaulted the little girl after he killed her and planned to eat the corpse.

Meat tenderizer and barbecue skewers found in his apartment were intended for the little girl, District Attorney Tim Kuykendall said.

According to a police affidavit, Underwood confessed that he killed the girl, telling FBI agents: "Go ahead and arrest me. She is in there. I chopped her up."

Police said that while there were deep saw marks on the girl's neck, she had not been dismembered.

In a brief, tearful telephone interview with The Associated Press, Underwood's mother was in disbelief and horror over the accusations.

"This is something that I don't know where it came from," said Connie Underwood. "He was always a wonderful boy.

"I would like to be able to tell her family how sorry we are. I just feel so terrible.