Foundations of Forensic Psychology and Police Practice

Chapter 1: Introduction to Forensic Psychology

1.1 A Brief History of Forensic Psychology

Forensic psychology is the application of psychological principles and methods to the legal system. Its history includes early research on eyewitness testimony and the influence of suggestive questioning.

• Cattell (1895): Studied accuracy of eyewitness testimony by asking students to recall events; found answers were often inaccurate.

• Julian Varendonck: Demonstrated in court that children are easily influenced by suggestive questioning.

• Advocates in North America:

  • Hugo Münsterberg: Wrote On the Witness Stand, arguing psychology's relevance to law.

  • William Marston: First professor of legal psychology (1917), contributed to jury research and lie detection.

1.2 Theories of Crime

Theories of crime in forensic psychology are classified into biological, sociological, and psychological perspectives.

• Biological Theories:

  • Sheldon’s Constitutional Theory (1949): Crime is linked to body build and temperament; mesomorphs (muscular) are more prone to aggression and crime.

  • Chromosomal Theory (1965): Extra Y chromosome in males may increase aggression and criminal behavior.

  • Lead Exposure Theory (2000): Childhood lead exposure is linked to increased risk of criminal behavior.

• Sociological Theories:

  • Merton’s Strain Theory (1938): Crime results from the strain between societal goals and the means to achieve them.

  • Sutherland’s Differential Association Theory (1939): Criminal behavior is learned through social interactions.

  • Becker’s Labelling Theory (1963): Deviance is a result of society labelling individuals as criminals, which can promote further deviant behavior.

• Psychological Theories:

  • Eysenck’s Biosocial Theory (1964): Some individuals are born with personality traits that predispose them to criminality.

1.3 Psychological Experts in Court

Forensic psychologists may serve as expert witnesses, providing courts with specialized knowledge to aid in understanding psychological aspects of cases.

• Expert Witness: Offers opinions and information to help the court understand psychological relevance.

• Challenges:

  • Epistemology: Psychology seeks objective truths; law is based on subjective convincing narratives.

  • Nature of Knowledge: Psychology relies on empirical data; law relies on case analysis and precedent.

  • Methodology: Psychology uses group-based, experimental methods; law operates case-by-case.

• Key Cases:

  • People v. Hawthorne (1940): Psychologist permitted to provide opinion on defendant’s mental state.

  • Jenkins v. United States (1962): Court recognized psychologists as qualified to give expert testimony on mental disorders.

1.4 Modern Day Roles and Activities

Forensic psychologists work in clinical and research settings, applying psychological principles to legal issues.

• Clinical Forensic Psychologist:

  • May conduct research and practice.

  • Focuses on mental health and law.

  • Requires M.A. or Ph.D. and internships.

• Researcher Forensic Psychologist:

  • May conduct research on human behavior and law.

  • Requires graduate training in psychology and research.

Chapter 2: Police Psychology

2.1 The Police Selection Procedure

Police selection procedures are designed to identify candidates who possess the necessary skills and abilities for effective law enforcement.

• Earliest Tests: Lewis Terman Stanford-Binet intelligence test (1917).

• Stages of Development:

  1. Job Analysis Stage: Identify and define knowledge, skills, and abilities (KSAs) of a good officer.

  2. Construction and Validation Stage: Develop and validate instruments to measure KSAs in applicants.

• Validity Coefficients: Indicate the strength and direction of the relationship between test scores and job performance ratings.

• Job Analysis: Procedure for identifying KSAs that make a good police officer.

2.2 Police Selection Instruments and their Validity

Various instruments are used to assess police candidates, focusing on cognitive abilities and psychological health.

• Selection Interview: Used to determine which applicants possess KSAs important for the job.

• Cognitive Ability Tests: Measure verbal, mathematical, memory, and reasoning skills.

• MMPI: Assessment instrument for identifying psychopathological problems.

2.3 Police Interventions with Mental Illness

Police officers may encounter individuals with mental illness and must decide on appropriate interventions.

• Options include:

  1. Transporting the person to a psychiatric institution.

  2. Arresting and taking the person to jail.

  3. Resolving the matter informally.

• Use of Force: May be necessary in some situations.

2.4 Police Stress

Police officers face various stressors that can impact their health and job performance.

• Categories of Stressors:

  1. Intra-organizational: Excessive paperwork.

  2. Inter-organizational: Jurisdictional isolationism.

  3. Occupational: Human suffering.

  4. Criminal Justice System: Unfavorable court decisions.

  5. Public Stressors: Distorted press accounts.

• Consequences:

  • Physical health problems (digestive disorders, cancer, cardiovascular disease).

  • Psychological and personal problems (depression, PTSD, substance abuse, marital issues, suicide).

  • Job performance problems (decreased efficiency, absenteeism, tardiness, early retirement).

2.5 Preventing and Managing Police Stress

Strategies are implemented to help police officers cope with stress and adversity.

• Resiliency Training: Improves ability to adapt to stress and adversity.

• Psychological Debriefing: Intervention delivered after exposure to traumatic events to restore normal functioning.

Chapter 3: The Psychology of Police Interrogations

3.1 Police Interrogations

Police interrogations are structured processes used to obtain confessions and information from suspects. Techniques vary in psychological approach and legal acceptability.

• Mr. Big Technique: Officers pose as members of a criminal organization to elicit confessions from suspects; confessions are used in court.

• Reid Model of Interrogation: Three-part process:

  1. Gather evidence related to the crime and interview witnesses and victims.

  2. Conduct a non-accusatorial interview to assess deception.

  3. Conduct an accusatorial interrogation if deception is suspected, involving nine steps:

     1. Confront suspect with guilt, even if evidence is lacking.

     2. Develop psychological themes to rationalize or excuse the crime.

     3. Interrupt suspect’s denials to maintain control.

     4. Address suspect withdrawal with various techniques (e.g., reducing physical space).

     5. Exhibit sympathy and urge suspect to confess (appealing to decency).

     6. Offer explanations for the crime to encourage self-incrimination.

     7. Once responsibility is accepted, develop the admission into a full confession.

     8. Suspect writes and signs a confession.

3.2 False Confessions

False confessions can occur under various circumstances and are classified into three main types.

• Voluntary False Confessions: Suspect confesses without police coercion.

• Coerced-Compliant False Confessions: Suspect confesses due to police pressure, despite knowing they are innocent.

• Coerced-Internalized False Confessions: Suspect comes to believe they committed the crime after suggestive questioning.

• Internalization: Acceptance of guilt for an act not actually committed.

• Confabulation: Reporting of events that never occurred.

3.3 Criminal Profiling

Criminal profiling is a technique for identifying major personality and behavioral characteristics of offenders based on crime analysis.

• Deductive Criminal Profiling: Uses logical reasoning from crime scene evidence to predict offender characteristics.

• Inductive Criminal Profiling: Uses statistical comparisons with known offenders to predict characteristics.

• Organized-Disorganized Model: Categorizes crime scenes and offenders as either organized or disorganized.

Table: Deductive vs. Inductive Criminal Profiling

Profiling Type	Method	Basis
Deductive	Analysis of crime scene evidence	Logical reasoning
Inductive	Comparison with known offenders	Statistical determination

3.4 Criticisms of Profiling

Criminal profiling faces several criticisms, particularly regarding its theoretical basis and empirical support.

• Theoretical Base: Many profiling methods lack strong empirical support and rely on untested personality models.

• Classic Trait Model: Assumes stable personality traits determine behavior, which may not account for variability.

• Geographic Profiling: Uses computer models to predict offender movement and crime locations.

Additional info: Forensic psychology is a multidisciplinary field, integrating psychological research and practice with legal standards and procedures. Police psychology focuses on the selection, training, and well-being of law enforcement officers, while criminal profiling and interrogation techniques are central to investigative processes.