Posttraumatic stress disorder and criminal violence: Basic concepts and clinical-forensic applications

In a small number of felony murder cases, posttraumatic stress disorder (PTSD) has been used as an affirmative defense to plead not guilty by reason of insanity or to argue for diminished capacity as a mitigating factor at sentencing. This article traces the history of PTSD as a legal defense; describes the clinical criteria for diagnosing and assessing PTSD; outlines the legal criteria for the affirmative defense of not guilty by reason of insanity (NGRI) and mitigation on the grounds of diminished capacity; and discusses the applications and pitfalls of using PTSD as an exculpatory factor in crimes of violence, including murder.