Chapter 1: An Introduction to Forensic Psychology – Study Notes

Introduction to Forensic Psychology

Overview

Forensic psychology is a specialized field that applies psychological principles to legal issues and the justice system. This chapter introduces the history, roles, and functions of forensic psychologists, as well as the criteria for expert testimony in court.

History of Forensic Psychology

Early Research in Forensic Psychology

• Cattell (1895): Studied the accuracy of everyday observations and the relationship between confidence and accuracy in witness testimony.

• Binet (1900): Investigated suggestibility in children, comparing free recall to responses to misleading questions.

• Stern (1939): Conducted the 'reality experiment' in 1901, examining the impact of emotional arousal on eyewitness accuracy.

Early Court Cases in Europe

• Von Schrenck-Notzing (1896): Served as an expert witness on the impact of pre-trial press, introducing the concept of "retroactive memory falsification" (distinguishing between observed events and those heard later).

• Varendonck (1911): Demonstrated that children can provide inaccurate testimony if exposed to suggestive questioning.

Forensic Psychology in North America

• Munsterberg: Influential in police interrogations, published On the Witness Stand (1908), and advocated for psychology's role in the legal system (eyewitness testimony, crime detection, false confessions, suggestibility, hypnotism, crime prevention). His ideas were initially rejected by the legal community, but he is now recognized as "the father of forensic psychology."

• Criminal Justice Settings:

  • Clinic for juvenile delinquents (1909)

  • Laboratories for pretrial assessments (1916)

  • Psychological testing for law enforcement selection (1917)

Landmark U.S. Court Cases

• State v. Driver (1921): First instance of psychologist expert testimony; testimony was rejected, and the use of psychological and medical tests for lie detection was questioned.

• Jenkins v. United States (1962): Psychologists testified about schizophrenia; initially disregarded, but on appeal, the court ruled psychologists could provide expert testimony on mental disorders. This established psychologists as regular contributors to legal proceedings.

Progress in Canada

• Research on eyewitness testimony and jury decision-making.

• Leadership in corrections, risk assessment, and treatment.

• Canadian courts slower to accept psychologist testimony, relying more on psychiatrists due to different licensing standards.

A Legitimate Field of Psychology

• Forensic psychology is recognized as an established discipline, evidenced by high-quality textbooks, academic journals, professional associations, training opportunities, and recognition as a specialty by the APA (2001).

Definition and Roles of Forensic Psychologists

Definitions of Forensic Psychology

• Narrow Definition: Focuses on clinical aspects such as assessment and treatment, excluding research roles.

• Broad Definition: Encompasses all human behavior in relation to the legal system, including both research and practice. This textbook adopts the broad definition.

Roles of a Forensic Psychologist

• Clinician: Assessment and treatment of offenders, custody mediations, expert testimony, personnel selection, and critical incident debriefings. Must be a licensed clinical psychologist with forensic specialization, working in settings such as private practices, prisons, and hospitals.

• Researcher: Conducts research on legal system issues, including risk assessment strategies, eyewitness lineup procedures, offender treatment programs, and juror decision-making. Requires PhD-level training in forensic psychology.

• Legal Scholar: Engages in scholarly analysis of mental health law, policy analysis, and legislative consultation. This is the least common role.

Relationships Between Psychology and Law

• Psychology and the Law: Uses psychology to study the operation of the legal system and test assumptions (e.g., accuracy of eyewitnesses).

• Psychology in the Law: Applies psychology within the legal system, such as providing expert testimony in court.

• Psychology of the Law: Uses psychology to study the law itself, such as evaluating the effectiveness of laws in reducing crime.

Psychological Experts in Court

Functions of an Expert Witness

• Regular Witnesses: Testify only about direct observations.

• Expert Witnesses: Provide opinions based on relevant experience and knowledge, assisting judges and jurors as impartial educators.

Challenges of Providing Expert Testimony

• Experts must understand case details, their role, and communicate persuasively.

• Challenges arise due to differences between psychology and law, including:

Dimension	Psychology	Law
Epistemology	Objective	Subjective
Nature	Descriptive	Prescriptive
Knowledge	Nomothetic	Idiographic
Methodology	Experimental	Narrative
Criterion	Cautious	Expedient
Principles	Multiple Explanations	Single Explanation
Latitude of Behaviour	Limited	Expansive

• Difficulties in applying group-level research results to individual cases.

Admissibility Criteria for Expert Testimony

Frye Standard

• Frye v. United States (1923): Established the "general acceptance test"—procedures must be generally accepted in the scientific community.

• Criticisms: Vagueness of "general acceptance" and whether judges can determine this.

Daubert Standard

• Daubert v. Merrell Dow, Inc. (1993): Testimony is admissible if it is:

  1. Provided by a qualified expert

  2. Relevant

  3. Reliable

• Daubert criteria for reliability:

  • Peer reviewed

  • Testable (falsifiable through experimentation)

  • Recognized error rate

  • Adherence to professional standards

Mohan Criteria (Canada)

• R v. Mohan (1994): Canadian criteria for admissibility of expert testimony. Testimony must:

  1. Be relevant to the case

  2. Be necessary to assist the trier of fact

  3. Not violate any rules of exclusion

  4. Be provided by a qualified expert

Example: Application of Expert Testimony Criteria

In a criminal trial, a forensic psychologist may be called to testify about the defendant's mental state. Their testimony must meet the relevant admissibility criteria (Frye, Daubert, or Mohan) depending on the jurisdiction, ensuring that their methods are scientifically valid and their expertise is recognized by the court.

Additional info: Forensic psychology is a rapidly evolving field, with increasing recognition of its importance in both research and practice within the legal system.