Methamphetamine Motivated Murder: Forensic Psychological/psychiatric & Legal Applications in Criminal Contexts

Article excerpt

This article examines the clinical and forensic (psycho-legal) aspects of methamphetamine use. The author will describe the clinical and psychiatric effects of the drug on an individual's functioning. Forensic psychological/psychiatric issues including substance-induced psychosis relevant to a not guilty by reason of insanity defense, diminished capacity, and mitigation at capital sentencing will be addressed. Case law pursuant to forensic aspects of methamphetamine use will also be thoroughly explored.

KEY WORDS: Methamphetamine, substance induced psychosis, forensic psychology, forensic psychiatry, insanity, mitigation.

In recent years there has been an increase in violent offenses, often homicides that are committed while an offender is under the influence of methamphetamine. Methamphetamine use has various psychophysiological effects and can lead to paranoid thoughts, acute substance induced psychotic states, and ultimately intense aggressive and violent behavior (Hunt, Kuck & Truitt, 2005).

An offender who commits a criminal offense while under the influence of methamphetamine, like other offenders, may be evaluated at various stages of the legal proceedings. Such examinations may include competency to waive Miranda rights, competency to stand trial, mental state at the time of the offense, diminished capacity, mitigation at sentencing, and competency to waive mitigation and appeals. The time between one's Miranda warnings and an evaluation regarding competency to waive appeals may be many years. Similarly, an individual's physiological effects from the drug methamphetamine may linger for long periods of time, disrupting his cognitive and affective states, and impairing his ability to function in his legal proceedings.

The forensic mental health professional who is requested to examine an offender with a chronic history of methamphetamine use should have a knowledge base about the biopsychosocial effects of this drug on the brain, and subsequently the consequences on an individual's functioning and behavior. The drug's properties and interaction within the brain can lead to acute psychotic states and subsequent violence (Subcommittee on Crime, House of Representatives, 1995). It may cause symptoms similar to schizophrenia, paranoid type (Caton, Samet & Hasin, 2000; Sato, Numachi & Hamamura, 1992). The chronic methamphetamine user may likely have a history of mental illness and dual diagnosis status (Lin, Ball, Hsiao, Chiang, Ree & Chen, 2004). Consequently, it may be difficult for the forensic clinician to determine the etiology of the violent acts from a mental health standpoint.

This article explores how a forensic mental health expert witness can assist the court, jury, and legal counsel in applying his/her knowledge of the drug to various legal referral issues. For purposes of this article, this author will specifically consider methamphetamine-induced psychosis relevant to diminished capacity, insanity, and mitigation at sentencing.

What is methamphetamine?

Methamphetamine is a stimulant drug that came into vogue in Hawaii in the 1980's and found its way eastward to California. Lately it has become very popular in Midwest areas (Yudko, Murray-Bridges & Watson-Hauanio, 2003). Methamphetamine is classified as a Schedule II substance by the Drug Enforcement Agency under the Convention on Psychotropic Substances (United States Drug enforcement Agency, 2007). The drug is illegally manufactured in various forms including: "Crank," (methamphetamine sulfate); "Crystal," (methamphetamine hydrochloride); and "Ice" which is a pure form of D-MA-hydrochloride (Ray & Ksir, 2002). Ice is produced from chemicals that until recently could be purchased over the counter at drug stores but are currently under stricter scrutiny and not as readily available. The drug is rarely sold in pure form; rather, it is diluted with other chemicals. It is commonly produced by the reduction of ephedrine or pseudoephedrine. …