JOHNSTON COUNTY, N.C. — Preliminary autopsy findings show 4-year-old Sean Paddock was suffocated to death when he died last Sunday at his home.

Sean Paddock, 4, was wrapped in blankets so snugly that he lost consciousness, the state medical examiner said. Investigators said he was repeatedly wrapped up as punishment in the days before his death Feb. 26.

Sean's adoptive mother, Lynn Paddock, 45, is charged with his murder.

"The binding was a form of punishment and had occurred several times in the week leading to his death," Johnston County Sheriff Steve Bizzell said Friday. "This is the most extreme case of torture of a child I have ever seen."

John Butts, the state's chief medical examiner, reported Friday that he found bruises covering Sean's back and buttocks. Butts concluded those injuries did not kill Sean.

Authorities said Paddock found Sean in his bed, unresponsive and not breathing, at about 7 a.m. Sunday. Attempts to revive him were unsuccessful.

Emergency workers declared the child dead en route to a local hospital.

Last week, Johnston County Department of Social Services released a summary of its assessment of Paddock and her family conducted early 2005.

Social workers visited the Paddocks after a request from the Wake County Child Protective Services, which was handling the adoption case. Sean's foster mother reported a severe bruise on the boy's backside and did not believe Paddock's claim that the bruise was a result of a fall.

Wake County is expected to release more information about the adoption case on Monday.

District Attorney Tom Lock said he will consider whether to indict Paddock for first-degree murder, saying torture would merit pursuing the toughest homicide charge.

Paddock also faces felony child abuse charges. Four of her other adopted children are now in the custody of Johnston County's Department of Social Services.