Deception Detection Techniques

Unit 6: Deception

• This unit covers deception, including tools for detecting deception, behavioral cues, and deception disorders.
• Students are asked to evaluate their ability to spot a liar, considering the cues they looked for.
• Common questions include how often someone lies in a day, and what the most common reason for lying is.

Deception Detection Tools

• Polygraph: Physiological measures (respiration, heart rate, sweating) used for centuries. Not a lie detector, but based on the belief that deception leads to physiological change. It's not admissible in Canadian courts. It is still used in employee screening, but not by law enforcement.
• Thermal imaging: Detects facial warming due to blood flow.
• ERP (Event-related brain potentials): P300 used to detect guilty knowledge.
• fMRI (Functional magnetic resonance imaging): Different brain areas activated during lying vs truth telling.

Deception Disorders

• Factitious disorders: Intentionally produced symptoms. Internal motivation. Absence of external incentives. Lack of insight into underlying motivations.
  • Munchausen syndrome: Deliberately produces physical complaints; seeks treatment. Harm self to perpetuate symptoms. Chronic and challenging to treat.
  • Munchausen syndrome by proxy: Reports/creates symptoms in children. Generally the mother of a young child, age 4 or younger.
• Malingering: Symptoms under voluntary control. External motivation, such as avoiding punishment, workers compensation. Prevalent in forensic settings.
• Defensiveness: Conscious denial or minimization of symptoms. Present themselves in a favorable light. Often seen in sexual offenders.

Types of Polygraph Tests

• Relevant/Irrelevant Test: Questions are relevant or irrelevant to the crime. Larger physiological response to relevant questions indicates deception.
• Comparison Question Test (CQT): Three types of questions: irrelevant, relevant, comparison. The CQT begins with a pre-test interview and has two stages: 1. Examiner stresses the accuracy of the polygraph. 2. Comparison questions are developed.
  • Sample questions: Irrelevant questions pertain to the respondent's identity; relevant questions deal with the crime; comparison questions deal with prior behavior and designed to evoke anxiety.
  • Possible outcomes: Truthful, deceptive, inconclusive. Scoring: Comparison > Relevant: +1, +2, +3; Relevant > Comparison: -1, -2, -3.
  • Results: +5 or higher = truthful; -5 or lower = guilty
  • Problems: Innocent suspects can fail the test and guilty suspects can pass.
• Concealed Information Test (CIT): Doesn't assess deception. Assumes only someone with knowledge of the crime will recognize the details. 10 multiple-choice questions; 1 correct option; 4 foils. Inaccurate at detecting guilty participants, but high at identifying innocent participants

Polygraph Research

• Laboratory experiments: Volunteers simulate criminal behaviour. Ground truth is known. High level of control. Limited application to real-life situations.
• Field studies: Use actual suspects in real-life situations. Compare original vs. blind examiners. Quantify failed polygraphs and guilty confessions. High realism, however, ground truth is not known, and does not include polygraph beaters.

Polygraph Accuracy

• Comparison Question Test (CQT): Majority of guilty suspects are correctly identified (84%-92%), while 9%-24% of innocent suspects are falsely identified as guilty.
• Concealed Information Test (CIT): Very accurate for identifying innocent participants (up to 95%). Less accurate for guilty participants (76%-85%).

Polygraph Conclusions/Summary

• Not a lie detector.
• Dependent on questioning techniques and interviewee's beliefs.
• Research raises concerns. Requires caution.

Unit 7: Eyewitness Testimony

• Memory is malleable and changes over time, despite the observer's lack of awareness of these distortions.
• Memory is constructed and reconstructed, and repeated processing of memory causes it to change.
• Encoding, storage, retrieval are the three stages of memory formation; Encoding - Perceiving events, Storage - Storing the information, and Retrieval - Retrieving the information from the storage.
• Factors affecting perception: Change blindness (Change in visual stimulus is introduced but observer does not notice it); Stress (Yerkes-Dodson Law: Some stress, but not too much, is optimal).

Factors Affecting Retrieval

• Inferences: People guess to fill in gaps.
• Stereotypes: Fill in gaps with related information.
• Partisanship: Biases affecting memory.
• Scripts/Schemas: Typical vs. real information.
• Emotional Factors: Anxiety blocks retrieval.
• Context Effects: Cues affecting memory.
• Time: Memory slippage.
• Post-event information: Alterations to memory after events.
• Enhancing memory: Other witnesses improve memory.
• Compromising memory: Other witnesses impair memory

Types of Memory Retrieval

• Recall memory: Reporting details of a previously witnessed event/person.
• Recognition memory: Reporting if current information is the same as previous information (e.g., lineups).

Measuring Recall and Recognition

• Recall: Amount of information; types of information (peripheral vs. central); accuracy (correct information, omission errors, commission errors).
• Recognition: Accuracy; types of errors.

Police Questioning

• Goal: Collect complete and accurate information.
• Short questions; interruptions during witness testimony; off-topic questioning; leading questions all negatively effect accuracy.
• Implications: Misinformation effects lead to changes in reporting; phrasing of questions can cause witnesses to misremember.
• Explanations of Misinformation Effect: Misinformation acceptance, source misattribution, memory impairment.

Interviewing Strategies

• Hypnosis: Techniques can increase details in testimony, but these aren't necessarily accurate; increase suggestibility
• Cognitive Interview (CI): Based on retrieval techniques. Uses: mental reinstatement of context, report everything, changing perspectives, recalling in different order. Increased amount of accurate information.
• Enhanced Cognitive Interview (ECI): Includes: rapport building; supportive interviewer behavior; transfer of control; focused retrieval; witness compatible questioning.

Lineups

• Suspect vs. Perpetrator: Suspect is the person the police think committed the crime; Perpetrator is the person who actually committed the crime.
• Lineup Procedures and Formats include: sequential and simultaneous lineups; photo arrays; show-ups; walk-bys.
• Two strategies for selecting foils are: Similarity-to-Suspect Strategy and Match-to-Description Strategy.
• Identification decisions (Lineups): Target-present: Correct identification, Foil identification, False rejection. Target-absent: Correct rejection, Foil identification, False identification.
• Guidelines for improvement: Video tape;Inform witnesses; Present lineup sequentially; Avoid feedback after testimony.
• Issues in lineups include: Bias (in foils, clothing, instructions, suspect); Live or photo lineups.

Video Surveillance

• Errors in video can happen in lighting, quality, or disguises.

Voice Identification

• Accuracy of identification depends on: voice length; accent recognition.
• Accuracy lessens if audio has whispering or emotion; more foils present; target voice is placed later in the lineup.

Unit 8: Child Victims & Witnesses

• History: Attitudes about children changed, with earlier views (e.g., Salem Witch Trials) and the early 1900s suggesting negativity towards testimony.
• Reporting: Memory, language, social norms all affect children's reporting.
• Interview Protocols: CBCA (Criterion-based Content Analysis); step-wise interview; narrative elaboration; cognitive interview; NICHD (National Institute of Child Health and Human Development) Protocol.
• Lineups: Children have problems with sequential lineups; Elimination lineups are more effective for children.
• Legal: Testifying in court (competency inquiry; Bill C-2); courtroom accommodations (screens/shields; closed-circuit TV; support person; prerecorded video).
• Summary: Questioning, development, language, social norms affect children's testimony. NICHD protocol, elimination lineups, courtroom accommodations, and proper protocols are key.

Unit 9: Juries

• Purpose of Juries: Apply law; protect from out-of-date laws; community conscience; increase knowledge of justice system.
• Types of Offenses: Summary offenses, indictable offenses, and hybrid offenses; the type of offense determines the method of trial
• Jury Selection Process: Jury Act outlines selection from random names in the community; jurors are summoned to court and judge explains process for selection. Challenges to Jury Selection (peremptory challenge and challenge for cause).
• Juries can be selected by a broad-based approach (assessing traits and attitudes during the voir dire) or a case-specific approach (using a case-specific questionnaire to create a profile of the "ideal" juror, followed by questioning of prospective jurors).
• Jury Behavior can be studied by analyzing their behavior, which includes the act of reaching a verdict, predicting a verdict, and nullification.
• Research Methods include: archival records, simulation, field studies, and post-trial interviews. Methods have high/low external & internal validity.
• Current Issues include: CSI Effect, law and religion, jury duty and PTSD, and additional psychopathology among jurors.
• Grand Juries: Determine whether criminal charges should be brought, without judge, not unanimous needed, typically use preliminary hearings.

Unit 10: Psychopathy

• Definition: Personality disorder; Intra-species predators; use charm or violence, show no remorse/shame. Seen in many cultures.
• Measurement: Hare PCL-R (Semi-structured interview; scored 0-2); Self-reports: PPI-R & SRP. There are two factors: Factor 1 (glibness, grandiose sense of self-worth, pathological lying, conning/manipulative, lack of remorse, shallow emotions, lacks empathy, and fails to accept responsibility), Factor 2 (need for stimulation, poor behavioral controls, early behavioral problems, lack of realistic long-term goals, impulsive, irresponsible, promiscuity, and criminal versatility).
• Psychopathy and Offending: High correlation with criminal behavior; often start offending young, persist for longer periods, engage in more violence. Fraud is closely linked with psychopathy.
• Psychopathy characteristics and causes: Difficulty avoiding punishment, low anticipatory responses, low pain sensitivity, low concern for pain in others.
• Causes: Heritability and environmental factors (criminal parents, neglect, abuse), cognitive/emotional deficit (don't pay attention to inhibitory information, lack of response to emotional items).
• Treatment: Can psychopaths be treated? Violent recidivism is possible, with potential reductions in reoffending for treated nonpsychopaths, but increases for psychopaths. Treatment more successful with youth than adults.
• Case Study: Ted Bundy, American serial killer with insights into thinking of a serial killer gained from prison interviews.
• Summary: Psychopathy is a complex personality disorder; PCL-R is a key measure. Myths exist about psychopathy; violence and criminality are correlated.