ABC interviewed forensic psychiatrist Dr. James Knoll for psychological perspective on the case .
He answered viewers ' questions via video on April 23 , 2009 , and via site comments on April 27 , 2009 .
ABC interviewed forensic psychiatrist Dr. James Knoll for psychological perspective on the case and he answered viewers ' questions via video on April 23 , 2009 , and via site comments on April 27 , 2009 .