Sean suffocated in February 2006 after he was wrapped so tightly in blankets he couldn't breathe. Lynn Paddock, his adoptive mother, is on trial on a charge of first-degree murder in his death. If convicted, she faces life in prison.

Dr. Sharon Cooper, a forensic pediatrician from Fayetteville, testified that Sean must have been terrified and probably panicked and hyperventilated. He likely thrashed his body, further hampering the flow of oxygen to his brain, she said.

Cooper said Sean eventually lost consciousness but might have lived four more minutes or so before his heart finally stopped. He could have survived, she said, if the blankets had unwrapped and someone had performed CPR.

Cooper was the state's concluding witness as prosecutors completed their case today. Defense evidence begins Monday.

Sean's biological grandfather, Ron Ford Sr., sighed and leaned back against a courtroom bench as Cooper described Sean's death. Ford came to court today for the first time during Paddock's trial.

He said he had stayed away, fearing he couldn't stomach the details about the life Sean and his brother and sister lived at the Smithfield farmhouse of Lynn and Johnny Paddock.

Ford has filed a lawsuit against the state, Wake County Human Services and Children's Home Society, the private agency that placed his three grandchildren with Lynn and Johnny Paddock. He said he wants to know why Sean, Hannah and David ended up with the Paddocks.

The children had lived for several months with Ron and Leanne Ford, their paternal aunt and uncle, after they were taken away from their biological parents. Wake County social workers had determined that Sean and his siblings had been neglected and that one of the children had been abused.

The Fords struggled financially to support their own three children, plus Sean, Hannah and David. They asked Wake Human Services to put the children in foster care until they could figure out their finances. The children were introduced to the Paddocks little more than a year later.

Ford saw his oldest grandson, David, at a supermarket in Clayton two months ago. David, now 11, has been adopted by a new family. The boy asked his grandpa, "You know Sean died, right?"

Ford sobbed and said he asked David's new mother if he could take a picture of his grandson. He said that David looked happy.

Earlier today, Cooper testified that the youngest of Paddock's six adoptive children were starved in the Paddock home. Hannah, David and Kayla Paddock have been gaining weight since they left the home, Cooper said.

At the time of Sean's death, Hannah was 7, Kayla was 8, and David was 9. In the past two years, Hannah has gained 28 pounds, more than four times the weight gain doctors expect to see for a child of her age. Kayla gained 19 pounds, and David picked up 14 pounds.

Cooper said that the swift weight gain shows just how underweight the children were while living in the Paddock home.

Defense attorneys grilled Cooper about how much she was being paid for her testimony. Cooper was paid for the medical exams she performed on the Paddocks' surviving children and the time she is spending on court; experts are often reimbursed for the time they spend consulting on criminal cases.

Paddock's attorneys strongly objected to Cooper's testimony and have complained to Judge Knox Jenkins that the doctor didn't turn over all the medical studies upon which she based her opinion. But Jenkins refused their requests to declare a mistrial.

Prosecutors contend that Paddock engaged in calculated, sadistic torture of her six adopted children.

Typically, a jury must find that a defendant premeditated a killing to be guilty of murder in the first degree. Prosecutors are not saying that Paddock calculated Sean's death. Instead, they have suggested that they will ask the jury to find her guilty of first-degree murder through a more unusual legal theory: murder by torture.