Durham man charged with killing son to use 'sleepwalking defense'

Joseph Anthony Mitchell, 49, rejected a plea deal Friday and pleaded not guilty to one count of first-degree murder and two counts of attempted first-degree murder. His trial was set for March.

Blake Mitchell was suffocated on Sept. 22, 2010, in the family home at 17 Thistle Trace. Two other children in the home at the time, Devon Mitchell, 10, and Lexi Mitchell, 13, told investigators that they awoke to find their father trying to cover their mouths or faces, and they had to fend him off, according to court documents.

Joseph Mitchell was found with stab wounds and cuts that authorities said were self-inflicted.

Defense attorney Jay Ferguson has filed notice that Mitchell plans to argue the defense of automatism at trial and will have an expert witness provide testimony to support that claim.

Automatism implies a lack of voluntary action or an unconscious action. It's sometimes referred to as a "sleepwalking defense," where defendants argued they weren't guilty of a crime because they were sleepwalking and weren't aware they had done anything wrong.

Investigators have said the Mitchell family had suffered numerous financial setbacks, and their foreclosed home was close to being turned over to a bank at the time of Blake Mitchell's death. They also obtained evidence that Joseph Mitchell had had at least one affair, according to court documents.