Sean, 4, suffocated in the attic of Lynn and Johnny Paddock's farmhouse in February 2006. Lynn Paddock, Sean's adoptive mother, is on trial on a charge of first-degree murder, accused of binding the child so tightly in blankets that he could not breathe.

Medical Examiner John Butts explained to jurors exactly how the bondage could have led to death. Sean's lungs could not fill with air because of the tight wrappings. As a result, his brain was deprived of oxygen.

Butts also found linear bruises marking Sean's back, from his shoulder to his buttocks. Jurors looked at photos taken during the autopsy. They saw red blotches on Sean's neck and face, which, Butts explained, were burst capillaries brought on by compressions in his chest.

Earlier today, a crime scene investigator testified that he found small strips of duct tape, urine-soaked blankets and a sheet stained in blood in the attic where Sean Paddock slept the night he died.

Paddock's stepdaughter, Jessy, told jurors earlier this week that she had seen Sean's entire head duct-taped the night before he died.

One by one, Ron Mazur from the Johnston County Sheriff's Office pulled six blankets from brown paper bags. Mazur testified that the blankets reeked of urine.

Mazur also showed jurors two pieces of plastic plumbing supply line collected from the Paddocks' home. Mazur said that Johnny Paddock, Lynn's husband, had handed them over, saying that his wife used them sometimes to discipline their children.

Sean was one of six children adopted by the Paddocks. The children told jurors earlier this week that their mother would strike them with the pipe to discipline them. The youngest children told social workers it was a "whipping stick."

Earlier today, a daycare teacher told jurors that she reported to social workers finding bruises on Sean after he visited the Paddocks before the couple adopted him.

Latesha Sherrod said she saw the bruises in January 2005 after Sean, then 3, returned from a weekend visit with the Paddocks. Sean hesitated to sit down, and she asked him what was wrong.

"He said his new mom hit him with a long thing," Sherrod said.

Sherrod testified that she called her supervisor at the daycare, and they alerted Wake County Human Services.

Wake authorities who received the report asked Dee Ethridge, a social worker for the Johnston County Department of Social Services, to check on the Paddock children at their Smithfield farmhouse.

Ethridge testified this morning that she asked the older Paddock children whether they'd ever been physically disciplined. Their parents were in the room at the time.

All children swore they were disciplined with timeout. Ethridge said the house was neat and clean, there was plenty of food in the cupboards, and the children were dressed appropriately.

Social workers in Wake County eventually concluded that Lynn Paddock was telling the truth when she said Sean had fallen out of a bunk bed at their home. They closed their investigation, and Sean and his older brother and sister went to live with the Paddocks permanently two months later.