Introduction to Forensic Psychology

Forensic Psychology Definition

• Examination of human behaviour in relation to the legal system.

Roles of a Forensic Psychologist

• Clinical practice focuses on mental health and law, training involves an M.A. or Ph.D. in clinical psychology and internships
• Experimental research focuses on human behaviour and the law, training involves a Ph.D. in psychology
• Legal scholars research and analyse mental health law and policy, training involves a Ph.D. in psychology plus legal training (e.g., LL.B.)

Clinical Forensic Psychology

• Deals with practical and mental health issues within the legal system.
• Work settings include special hospitals and institutions.
• Forensic psychiatrists can prescribe medication, unlike psychologists.

Research Forensic Psychology

• Typically research-oriented, often based in universities.
• Explores aspects of psychology related to the legal system.

Other Forensic Areas

• Anthropology: Uses old bones for information.
• Entomology: Studies bugs on corpses to estimate time of death.
• Odontology: Deals with teeth, particularly in abuse cases.
• Chemistry: Analyses chemicals found at crime scenes.
• Pathology: Determines the cause of death.

Early Research in Forensic Psychology

• Cattell (1895) questioned the accuracy of everyday observation.
• Binet (1900) studied suggestibility in children, emphasizing open-ended questioning.
• Stern (1910) researched eyewitness memory with a 'reality experiment'.
• Von Schrenck-Notzing (1896) found pre-trial press can cause memory falsification.
• Varendonck (1911) showed children can give inaccurate testimony from suggestive questioning.

Functions of an Expert Witness

• Provide specialized understanding relevant to a case
• Represent expert opinion, needing not be psychologists
• Offer opinions unlike regular witnesses who testify only on direct observations.
• Both sides in a case can select expert witnesses, even with opposing views

Deception Contexts

• People lie in face-to-face interactions (27%), emails (14%), texts (21%), and phone calls (37%).

Detecting Deception

• Signs to observe: -Emotional arousal -Facial expressions like microexpressions and emotional leakage. -Increased blinking except in those with "poker faces" -Too much eye contact -Slowed speech rate with pauses. -Controlled, rigid behaviours, with decreased hand gestures except in psychopaths. -Verbal cues includes less detail, out-of-order stories, and higher voice pitch. -High cognitive load makes liars noticeable.
• Liars rarely correct themselves, whereas truth-tellers admit ignorance

Professional Deception Detection

• Vrij (2000) accuracy rates: 67% for truths, 44% for lies.
• Professionals vary in accuracy due to truthfulness bias and reliance on incorrect cues.

Polygraph Testing

• Relies on physiological changes during deception.
• Measures respiration, heart rate, blood pressure, and sweating.
• Used in criminal investigations and pre-employment screening.
• Monitoring of sexual offenders in the United States.

Polygraph Types

• Comparison Question Test (CQT): common in the US and media.
• Concealed Information Test (CIT).

CQT Phases

1. Pre-test interviews develop comparison questions.
2. Polygraph exam measures physiological responses to questions. 3 .Post-test interview pressures deceptive suspects to confess.

Comparison Question Test (CQT)

• Pro-social questions involve helping others; anti-social questions involve undesirable behavior.
• Guilty individuals react strongly to relevant questions while innocent react more to comparison questions. -Accusations may cause false confessions and make them the only suspect
• Deception is detected with 74-92% accuracy, but 9-24% of innocents are falsely accused.
• Some scorers are more skilled than others.

Concealed Information Test

• Not commonly used in Canada, but standard in Japan and Israel.
• Determines if a suspect possesses knowledge only the criminal would know
• Uses multiple-choice questions, only one option is correct
• The suspect will react to correct information
• Detects deception with 76-88% accuracy, falsely accusing 1-5% of innocents.

Polygraph Admissibility

• Inadmissible in Canadian courts, but allowed in USA state if it's agreed by both parties
• Used for further investigation and collecting confessions

Polygraph Countermeasures

• Physical and mental countermeasures reduce effectiveness of CQT and CIT.
• People can learn to 'beat' polygraph tests.
• 50-100% can beat them
• Involves actions like biting the tongue and contracting anal muscles

Malingering

• Intentionally faking symptoms for external gain like avoiding punishment or obtaining drugs.
• Contrast with somatoform disorders (unintentional) and factitious disorders, like Munchausen syndrome, for attention.

Detecting Malingered Psychosis

• Assess if one claims that they are crazy
• Clues involve rare or absurd symptoms, atypical delusions, or continuous hallucinations
• They also report the clinician of not believing them, look for accomplices and criminal histories

Malingering Assessments

• MMPI/MMPI-2: self-report personality tests with scales to detect atypical symptoms, also is useful for detecting malingering and all items are true or false questions
• Act differently in tests

Polygraph Technique

• Based on that truthful people are not anxious
• Polygraph is a device that records autonomic nervous system responses
• Sweat is tested from fingertips, Heart rate is measured by inflated blood pressure.
• Training is restricted to police, military personnel.

Polygraph Applications

• Aids criminal investigations, insurance claims, and monitoring sexual offenders
• Polygraph disclosure uncovers past behaviour.

Polygraph Tests

• Comparison Question Test (CQT) investigates criminal acts and creates comparison questions
• Examiner gets familiar with the case, then uses that to create comparison questions
• Relevant are guily/innocent questions

Concealed Information Test (CIT)

• Doesnt access deception, but it determines a criminals knowledge on a crime
• Law enforcemnt in Canada and USA does not usually use the CIT. Israel and Japan do.
• One critical and four foil options

Validity of Polygraph Techniques

• Classified into laboratory and field studies
• Laboratory studies use mock crimes with volunteers but the results have limited application to real life
• Field studies deals with real situations

Polygraph Validity

• Real-life situations and real criminals with real polygraph examinations
• Problem: establishing ground truth with indicators of guilt
• New measure of deception - Thermal imagining

Beating a Polygraph

• Can be done with countermeasures
• Physical- tongue bitting
• Mental-counting backwards

Polygraph Evidence

• Obtain general acceptance by the relevant scientific community
• Brain-Based Deception Research: use brain responses to detect deception

Verbal/NonVerbal Lying

• Verbal: speech fillers, pitch of voice
• Nonverbal: Gaze aversion, smiling

Malingering/Deception

• Deception refers to a component of some psychological disorders

Disorders of Deception

Malingering Models

• Pahtological
• Criminological
• Adaption

Studying Malingering

• Basic designs are case study and simulation: a specific disorder is compared with two groups
• To examine detections methods, there are four groups
• Clinical experimental
• Clinical control
• Nonclinical experimental
• Nonclinical control

Study Designs

• Known-goups
• Maligererd psychois; identifiying patients and faking symptoms

Interview-Based Method:

• Used for the Structure Interview of Reported Symptoms (SIRS)

Self-Report Questionnaire:

• MMPI assesses offenders

Police Investigations

• Obtain confession, gain information to help the investigation

Coercive Police Nature

• Mid-1900s: whipping, the use of stun gun.
• More recently, deceit is used (lying on the scene)

Reid Model of Interrogation

• A common type, scripted and can lead to false confessions: it's now allowed in the UK
• The thought that people make choices to benefit them

Reid Model Stages

1. Gather evidence of the crime and interview
2. Non-accusatorial to assess guily/deception
3. Break down the suspects

Nine Steps of Reid

• Step 1: suspect is immediately blamed
• Step 2: rationalize, come up with issues for suspect
• Step 3: Interragator interrupts so suspect doesnt get upperhand

Reid Design

• Designed to make people confesse

Minimization/Maximization

• Consists of the interrogation techniques
• Minimization: soft tactics that indicate sympathy
• Maximization: Scare tactics, intimidating

Reid Model Use

• Canadian police officers use the Reid Model but doesnt follow the same techniues

Risks with Reid Model

• investigator bias, police aren't great at detecting deception.

Alternative approach to Reid model

• PEACE model: Planning, preparation, engage, explain, account, closure, and evaluation.
• Interview method is conversation management

Mr. Big

• Undercover officers
• Target suspect
• Bribe

False Confessions

• Can occur if someone confesses on a crime they did not commit
• 25% of conviction cases have false consessions
• Voluntairly, or coerced

Types of False Confessions:

Studying Confessions

• Laboraty studies
• Criminal profiling is identification

Criminal Profiling

• Criminal profiling: technique for identifying the personality and behavioural features of an offender based on an analysis of the crimes they have committed (includes crime scene).
• Criminal profiles will focus more on criminal behaviour and the like

Profiling Goals

• Help law enforcements, prioritize suspects

Profiling Approaches

Profiling Model

• Most known inductive appraoch is the organized-disorganized model used by the FBI

Profile Behaviours

Profile Characteristics

Profiling Validity

• Not a lot of research on profiling
• Criticized

Geographic Profiling

• Analysis of crime scene locations to determine offender's residence
• Relaiable, targets the same suspect