Defense attorney John Caine said Friday that the cause of death of a 5-year-old boy found buried in his parent's back yard last month was asphyxia.

Caine said he had read the autopsy report for Nicholas McGuire but that the Utah Medical Examiner's Office had yet to determine if the manner of death was accidental or intentional.Meanwhile, the boy's mother and stepfather were arraigned in 2nd District Court Friday afternoon before Judge Ronald O. Hyde. Debra and James Thomas are both charged with 3rd degree felony abuse or desecration of a human body.

The couple asked for a continuance to enter their pleas. Deputy Weber County Attorney Bill Daines said he had no objections because the investigation was ongoing and that more charges may be filed against the couple. Hyde set Jan. 18 for the couple to enter their pleas.

The Thomases were arrested Dec. 17 after Roy police dug up the small boy's body - stuffed inside two garbage bags - in their back yard. The criminal complaint alleges that the mother and stepfather buried the boy between Nov. 11 and Nov. 16.

The two were booked into the Weber County Jail where they remain in lieu of a $35,000 bond each.

Debra, 28, and James, 30, both waived their preliminary hearing to determine if there was enough evidence to bind them over for trial. Once they enter a plea in 2nd District Court, a trial date will be set. If convicted, on the charges, both could be sentenced to serve up to five years in the Utah State Prison.

Four other children were living in the Thomas home when the couple was taken into custody. They were turned over to the Division of Family Services and placed in foster homes.

The Associated Press also reported that Roy investigators are investigating the possibility that James may have had another child who died previously.

Sgt. Edward Rhoades said Friday two detectives had been sent to interview acquaintances, family members and family service workers in another city.

Rhoades declined to give specifics about the purported death of a second child, except to say the youngster was James Thomas' child either from a previous marriage or a former girlfriend.

"We don't have information other than that there was a second child, one of his children that supposedly died of leukemia or some disease. We heard there is another death, but whether it's related to this incident we don't know," he said.

Rhoades would not say where the two detectives traveled to follow up the report.

Roy Lt. Kay Hargis said investigators also investigated an earlier report that the Thomases gave away an infant son to friends in Arizona. "We found the child to be in a good home and well taken care of," he said.