Violence Prediction and Risk Analysis - Pacific Institute for the Study of Conflict and Aggression

Brain Perfusion SPECT Scans & Methamphetamine

Left lateral view of brain of young, adult male. No more "ice" use but progressive damage 4 mos. later. (March 1996)	Frontal view of same individual.
Normal brain of young adult male.
Lateral view of 44 yr old male with a history of traumatic brain injury.	Bird's-eye view of brain of 61 yr old man with dementia.

If you don't already have Adobe Acrobat Reader, you will need
to download it to read the documents available below.

Download Adobe Acrobat

Methamphetamine Use and the Mental Health
Expert in Criminal-Forensic Contexts
H.V. Hall, S.B. Twenlow, S.B. McPherson, 1999

Download the PDF version of this key article published by the Pacific Institute.

ABSTRACT

This article investigates the evidentiary value of criminal-forensic aspects of expert testimony on methamphetamine use to judicial decision-making. One cross-validating finding is that some aspects of methamphetamine are unique–viz., the risk of cerebral damage even with infrequent use of the drug, the altered perceptions and cognitions of the abuser rendering his or her credibility in reporting events a significant issue, the strong association with violence to others, and the similarity of the symptomatic picture to paranoid schizophrenia. The importance of this topic is revealed by an analysis of state statutes and case law in one state, as well as some Federal guidelines and cases, in addition to an analysis of the role of the expert witnesses in some trial proceedings. Analysis reveals that the trier of fact typically defers to mental health experts regarding methamphetamine. Confusion and complexity reign when multiple experts, coming from different theoretical viewpoints, clinical experiences, and databases, testify in the same case. A contributing factor is that no current, integrated approach to the forensic issues concerning methamphetamine use has been heretofore available.

The empirical, forensic, and clinical aspects of methamphetamine use, including its prevalence and effects, are discussed. Daubert considerations for acceptance of expert testimony, victim/witness credibility, competency to confess and to stand trial, criminal responsibility, extreme emotion, and dangerousness are presented. The statutes, case law, and forensic psychological/psychiatric practice of clinicians are scrutinized in order to represent perspectives of both the prosecution and the defense. Although information regarding methamphetamine-related criminal behavior is rudimentary and continuously evolving, legal issues are addressed within both an existing framework of knowledge and recommended models to assess the decision path and proffered conclusions of the expert.

Download a PDF version of the Critical Historical and Crime Scene Factors utilized in risk analysis.
The scaled weights for calculating the total severity of violence shown by an individual stem from the National Institute of Justice's study of over 60,000 Americans (see Empirically-Based Methods).