article_snippet: But a defense expert said Mitchell's stress and lack of sleep likely resulted in 'non-REM parasomnia,' a sleep disorder whose sufferers can perform random acts unconsciously.
article_snippet: Because of a sleep disorder whose sufferers can perform random acts unconsciously, him was incapable of exercising criminal intent, a defense expert said.
article_snippet: : A defense expert said Mitchell's stress and lack of sleep likely resulted in a sleep disorder whose sufferers can perform random acts unconsciously- including killing his son .
highlights_snippet: Expert witness said Joseph Mitchell had a sleep disorder and was unconscious at the time of Joseph Mitchell attacks .
  