"Sleepwalking defense" looms for father accused of killing son, 4

DURHAM, N.C. -- Lawyers for a North Carolina man accused of killing his 4-year-old son more than four years ago say he may have been sleepwalking when he attacked the child and his two other children, reports CBS affiliate WRAL.

Joseph Anthony Mitchell went to bed on Sept. 21, 2010, and next remembers waking up in Duke University Hospital the following day, attorney Jay Ferguson told jurors as Mitchell's trial opened Friday.

In the intervening hours he suffocated Blake Mitchell to death, and attempted to kill 10-year-old Devon Mitchell and 13-year-old Lexi Mitchell, Durham County District Attorney Roger Echols said. Lexi Mitchell told investigators that they awoke to find their father trying to cover their mouths or faces, and they had to fend him off.

DA Echols said Lexi Mitchell thought she had dreamed that her father had tried to push her head into the mattress, only to be awakened by her brothers' cries later that night.

"She saw her father attacking Blake. She did what she could do to get him off, and he fled that room," Echols said. "Lexi went to her mother and brought her brothers into the room. Blake was unresponsive, and Lexi carried him."

The family called 911, and the children's grandfather, who lived with the family, ran to alert a nurse who lived next door, the prosecutor said.

Meanwhile, Joseph Mitchell had locked himself in his office, and authorities eventually found him with stab wounds and cuts to his torso and neck that Echols said were self-inflicted.

"The circumstances are bizarre, as his wife put it, 'mind-boggling,'" defense lawyer Ferguson said.

He described Joseph Mitchell as a loving father who never fought with his wife and who was excited about the possibility of landing a job with the Red Cross after a lengthy period of unemployment.

"Joe Mitchell had not been sleeping well. He'd go to bed, sleep for an hour then wake up and be up for the rest of the night. That shows the stress he was under," Ferguson said.

The defense plans to present evidence of automatism, which implies a lack of voluntary action or an unconscious action, during the trial. It's sometimes referred to as a "sleepwalking defense," where defendants argue they aren't guilty of a crime because they were sleepwalking and weren't aware they had done anything wrong.

Ferguson told jurors that Joseph Mitchell, now 50, simply walked away when his half-awake daughter elbowed and bit him to fend him off that night.

"That was not a man whose intent was to kill his daughter," he said, adding that he twice walked in and out of his boys' room before the fatal attack on Blake Mitchell occurred.

Echols said the family picture wasn't so rosy, noting that the house had been foreclosed and that Joseph Mitchell had, without his wife's knowledge, agreed to surrender the keys to a real estate agent on Sept. 22, 2010, for $500.

He faces one count of first-degree murder and two counts of attempted first-degree murder.