Forensic Psychology – Key Vocabulary

Definitions & Scope of Forensic Psychology

  • Narrow definitions
    • American Board of Forensic Psychology (1995): professional practice by clinical, counselling, neuro-, school psychologists who routinely offer expertise to courts.
    • APA (2001): psychologists who “foreseeably and regularly provide professional psychological expertise to the judicial system.”
  • Broad definitions
    • Bartol & Bartol (2006): research and/or practice examining human behaviour in relation to the legal system (e.g., eyewitness memory, jury decisions).
    • Goldstein (2003): application of psychological research, theory & practice to legal questions. • Practice ⇒ reports/testimony; Research ⇒ empirical studies.
    • Specialty Guidelines for Forensic Psychology (2011): application of psychological knowledge from any sub-discipline to legal, contractual & administrative matters.

Why Study Forensic Psychology?

  • Legal systems are human systems; psychological variables affect how they work.
  • Ensures best functioning of courts, policing, corrections.
  • Offers challenging careers blending science & practice.

Psychology–Law Interfaces (Haney)

  • Psychology AND the law – research evaluating how system works.
  • Psychology IN the law – psychologists hired as experts within current legal processes.
  • Psychology OF the law – study of the law itself (origins, obedience, deterrence).

Core Roles of Forensic Psychologists

  • Basic / applied researcher • Expert witness • Policy evaluator • Trial consultant • Evaluator (competency, risk) • Treatment provider • Correctional psychologist • Academic • Advocate.

Career Settings & Tasks (non-exhaustive)

  • Clinical practice (courts, hospitals, corrections) • Profiling • Risk assessment • Mediation • Jury role-play • Program evaluation • Consultation to police • Neglect / abuse investigations • Treatment programme design • Organizational & HR work.

Expert Witness Functions

  • Two functions: (1) Aid fact-finder’s understanding; (2) Offer opinion.
  • Distinct from regular witnesses who testify only to observed facts.

Science vs Law (Haney 1980)

  • Psychology: cooperative, nomothetic, empirical, descriptive, probabilistic, strict methods.
  • Law: adversarial, idiographic, precedent-driven, prescriptive, seeks certainty, liberal methodology.

Admissibility Rules

  • Canada (Mohan): evidence must (1) come from an expert, (2) be relevant, (3) be necessary, (4) not violate exclusionary rules.
  • USA (Daubert): plus reliability—peer reviewed, testable, known error rate, standards.

Historical Milestones

  • Ancient Chinese “rice powder” lie test.
  • 19ᵗʰ C: Wundt lab; Cattell on accuracy; Binet on child suggestibility; Stern’s reality experiments; first profiling; Von Schrenck-Notzing expert testimony.
  • 20ᵗʰ C: Münsterberg’s On the Witness Stand (1908); Brandeis brief (1908); Brown v Board (1954); AP-LS founded (1968); first JD/PhD (1974); Specialty Guidelines (1991/2011); APA specialty designation (2001).

Two Landmark Cases

Jenkins v United States (1962)

  • Issue: Can psychologists testify re mental disease?
  • Ruling: Yes—qualification based on training/experience, not medical degree.
  • Opened courtroom doors to clinical psychologists; emphasised judge as gatekeeper; laid groundwork for \text{Daubert}.

D.C. v L.K. & X (2013, QC)

  • Inuit customary adoption; father sought paternity, custody, \$50{,}000 damages.
  • Court: rectified birth certificate to include father; custody left with adoptive parents as “best interests” (\text{art.
    33 C.C.Q.}); progressive access ordered; punitive damages denied.

Education & Training

  • Clinical, experimental, or legal tracks; JD/PhD options.
  • Heilbrun model: 3 knowledge foci × clinical/experimental/legal applications.

Professional & Ethical Issues

  • Licensure required for independent clinical work (doctorate in BC, MB, ON, QC; master’s elsewhere).
  • Common dilemmas: confidentiality limits, multiple roles, client identification, bias, informed consent, competence maintenance.
  • Key codes: APA Ethics Code; Specialty Guidelines (2011).

Major Organizations & Journals

  • AP-LS (APA Div 41); ABFP; CPA; EAPL; ANZAPPL.
  • Journals: Law & Human Behavior; Psychology Public Policy & Law; Behavioral Sciences & Law.

Models of Justice Systems

  • Due-process vs crime-control.
  • Restorative vs retributive justice.
  • Canada: Charter detention rights; USA: Miranda rights.

Psychological Theories of Crime

  • Psychoanalytic: maternal deprivation (Bowlby).
  • Social learning: Bandura.
  • Personality: Eysenck (neuroticism + extraversion).
  • Learning-disability hypothesis (dyslexia, dyscalculia etc.).

Competency & Fitness to Stand Trial

  • \text{Adjudicative competency} umbrella.
  • Canadian standard (Criminal Code s.2): understand nature/object, consequences, communicate with counsel.
  • Key cases: R v Prichard (1836); R v Taylor (1992) “limited cognitive capacity”; R v Whittle (1994) harmony; R v M.A.W. (2008) extends to guilty pleas.
  • If found unfit: proceedings halted, restoration (usually meds) \approx 6 months; annual review; possibility of stay (Bill C-10) or absolute discharge (R v Demers 2004).
  • Instruments: FIT-R, MacCAT-CA, ECST-R, CAST-MR etc.

NCRMD / Insanity

  • McNaughton rules (1843). Canadian codification \text{Bill C-30 (1992)}.
  • Criteria: mental disorder ⟹ incapable of appreciating nature/quality or knowing act was wrong.
  • Dispositions: absolute, conditional, detention; Review Boards review annually; Winko v BC (1999) ⇢ detention only if significant threat.
  • Public myths: used \approx0.9\%, success \approx26\% vs perceived 44\%.
  • Automatism (sleep-walking, hypoglycaemia etc.). Severe intoxication defence revived in \text{R v Brown (2022)}.

Risk Assessment

  • Static vs dynamic factors; actuarial (e.g., VRAG, STATIC-99) vs SPJ (HCR-20).
  • Risk contexts: bail, sentencing, DO/LTO hearings, parole, NCRMD review.

Eyewitness Psychology

Sensation & Perception

  • Perception reconstructive; influenced by past experience, Gestalt laws (closure, proximity, similarity, figure-ground, pragnanz), arousal (Yerkes-Dodson), stress (Easterbrook narrowing), social conformity (Asch).

Memory

  • Encoding → storage → retrieval; susceptible to expectancy & post-event misinformation (Loftus).
  • Recognition ↓ detail/↑ false ID; recall ↑ detail.

Accuracy Findings

  • Correct ID often \le42\%; weapon focus; own-race bias; overestimation of height/duration.
  • Confidence malleable, weakly correlated with accuracy.

System Variables & Safeguards

  • Blind lineup administrator; unbiased instructions; fair foils; sequential vs simultaneous (sequential ↓ false positives in target-absent); confidence statement; video-recording.
  • Enhanced Cognitive Interview: context reinstatement, varied recall order, witness-compatible querying ⇒ \approx35\% ↑ correct info.

Jury Research

  • Representativeness & impartiality; threats = pre-trial publicity.
  • Remedies: change of venue, adjournment, challenge for cause.
  • Decision models: mathematical (little support) vs story model (Pennington & Hastie 1988).
  • Juror aids: note-taking helpful; questions clarify testimony.
  • Nullification possible when law conflicts with community conscience.

Social-Psychological Forces in Court

  • Stereotyping, obedience, conformity, groupthink, cognitive dissonance, fundamental attribution error, foot-in-door, intimidation, by-stander apathy.

Police Interrogation & False Confession

  • Reid model 9-step accusatory; minimisation vs maximisation tactics.
  • False confession types: voluntary, coerced-compliant, coerced-internalised.
  • Lab analogue (Kassin): \approx66\% falsely admitted blame under accusation + witness.
  • PEACE model as humane alternative.

Psychopathy

  • Personality style: grandiose, callous, manipulative, impulsive.
  • Hare PCL-R: 20 items scored 0–2; \ge30 ⇒ psychopath; normals \approx5; typical offenders \approx22.
  • Prevalence \approx1\% (general) but 5\times higher in males; commit \approx30\% of violent crime.
  • Neuro-biology: deficits orbitofrontal cortex, ACC, amygdala; weak punishment learning.
  • Social “advantages”: charm, fearlessness, focus.

Criminal Profiling

  • Assessment form using MO & signature.
  • History: Dr Bond (Jack the Ripper 1888); OSS profile of Hitler; Brussels (Mad Bomber, Boston Strangler); FBI BSU (Douglas, Ressler) organised/disorganised dichotomy.
  • Typologies: Holmes (visionary, mission, comfort, lust, thrill, power); Kelleher (female serial killers); FBI rapist & child-molester categories.

Risk Factors Revisited

  • Categories: dispositional (age, gender, impulsivity, psychopathy), historical (early antisocial, maltreatment), clinical (substance use, major mental illness with TCO), contextual (lack of support, access to weapons/victims).
  • Female-specific: self-harm history, low self-esteem; overall lower recidivism.

Family Law & Custody

  • Custody types: physical vs legal; sole/divided/split/joint.
  • Standards: Tender-years doctrine (obsolete); Best-Interest-of-Child (BICS) – considers health, adjustment, parenting capacity, child & parent wishes.
  • Additional preferences: biological parent, psychological parent, sexual orientation (research shows no difference), ethnicity/culture.
  • APA Guidelines: best interest, limits/bias, avoid dual roles, informed consent.
  • Evaluation methods: parent/child interviews, collateral data, tests (MMPI-2, MCMI-III, Rorschach, Raven, TAT, PCRI, Bricklin scales, CAT, projective drawings).
  • Empirical findings: joint custody beneficial if low conflict; < 8 yrs do best with primary caretaker; ≥ 8 yrs same-sex parent.

Sexual Offenders

  • CSC five groups: sexual-assault perpetrators; pedophiles; incest offenders; other (exhibitionism etc.); mixed.
  • Demographics: \approx99.7\% male; mean age \approx40; 75\% Caucasian, 16\% Indigenous.
  • Psych status: paraphilias common; most have diagnosable disorders; childhood abuse and substance issues prevalent; NOT typically psychopathic.
  • Recidivism (untreated): 14\% 5-yr, 24\% 15-yr; highest for offenders against boys & adult women; lowest for intrafamilial girl victims.
  • Treatment: CBT/behavioural targeting triggers; early start critical; limited efficacy for pedophiles ⇒ intense supervision.

Numerical / Statistical Highlights

  • 90\% wrongful DNA exonerations involved false eyewitness ID (Wells et al. 1998 – 36/40).
  • Eyewitness correct ID rates often <\,50\%: Buckhout 14.7\% (TV crime), 40\% (class assault), 42\% correct vs 36\% false (Cutler & Penrod).
  • Weapon focus & stress: high arousal ⇒ central detail ↑, peripheral ↓ (Easterbrook).
  • Psychopathy cut-off \ge30/40 on PCL-R; non-psych criminal mean \approx22.
  • False-confession lab: 50\% accusation + witness ⇒ 100\% signed confession, 66\% later admitted.

Formulae & Legal Clauses (LaTeX)

  • Standard of proof for guilt \text{beyond a reasonable doubt}.
  • Mohan criteria: {\text{expert},\;\text{relevant},\;\text{necessary},\;\text{no rule violation}}.
  • Canadian NCRMD test: \text{MD} \Rightarrow \bigl[\neg\text{appreciate nature or quality}\;\lor\; \neg\text{know wrongness}\bigr].
  • Yerkes–Dodson: \text{Performance}=f(\text{Arousal}); inverted-U.

Key Take-Home Connections

  • Psychology informs every stage of justice—from investigation (perception, interview), through trial (competency, eyewitness, jury), to disposition (risk, NCRMD).
  • Ethical, cultural, gender & developmental considerations permeate all roles.
  • Evidence-based practices (blind lineups, actuarial risk tools, PEACE interrogation, cognitive interviews) offer demonstrable accuracy gains & fairness.