Psychopathy evidence in legal proceedings

Evidence concerning psychopathic personality disorder (psychopathy) is frequently introduced in legal systems to address a wide range of questions that decision-makers (i.e., judges or juries) are tasked with adjudicating. These questions often revolve around defendants’ likely future conduct (e.g., the potential for violent and other types of criminal acts) but also may concern their diagnostic status or their ability to exercise volitional control over their actions. The types of cases in which psychopathy evidence is used tend to be ones involving potentially severe life-altering (e.g., indeterminate confinement) or even life-ending (e.g., capital punishment) legal consequences. In this chapter, we first review the uses of psychopathy assessment instruments in legal settings based on published case law and surveys of legal and mental health professionals. Next, we review various controversies concerning the relevance of psychopathy evidence in relation to the types of legal questions at issue, particularly in relation to its potentially stigmatizing impact on decision-makers. We conclude with a discussion of emerging issues in the assessment of this disorder and how these may impact the uses of psychopathy in legal systems in the future.