Psych 230 Forensic Psychology
What is forensic psychology? Narrow definition excludes many aspects. Broad definition: the research
endeavour that examines aspects of human behaviour directly related to the legal process and the
professional practise of psychology within, or in consultation with, a legal system that embraces both civil
and criminal law.
The roles of a forensic psychologist. The FP as clinician. Concerned with mental health issues as they pertain
to the legal system, include both research and practise in wide variety of settings such as schools, prisons,
hospitals and so forth, concerned with the assessment and treatment of persons with mental disorders within
the context of the law. On research side, validation of assessment tool used to predict the risk of an offender
being violent. On practical side, involve assessment of an offender to determine whether offender likely to
pose risk to community. Have to be licenced FP specialized in forensic area with doctoral degree or master’s
degree and intense period of practise. The FP as researcher. They are concerned with the study of human
behaviour as it relates to the law or legal system. They undergo PhD training focused primarily on a topic
related to FP. The FP as legal scholar. Less common. Likely engage in scholarly analyses of mental health law
and psychologically oriented legal movements, their applied work center around policy analysis and
The relationship between psychology and law. Psychology and the law: the use of psychology to examine the
operation of the legal system. Psychology is viewed as a separate discipline, examine law from P’s
perspective. Psychology in the law: the use of psychology in the legal system as that system operates. Take
different forms, provide testimony or help police investigation or extract confession. Psychology of the law:
the use of psychology to examine the law itself. A set of skills from multiple disciplines often important and
History of forensic psychology. Early research: eyewitness testimony and suggestibility. Psychology of
eyewitness testimony by Cattell found that answers were inaccurate. Alfred Binet showed that children were
highly susceptible to suggestive questioning techniques, free recall was most accurate, and leading questions
were not. William Stern’s reality experiment demonstrated that person’s level of emotional arousal can have
impact on the accuracy of the testimony. Early court cases in Europe. Albert von Schrenck-Notzing described
‚retroactive memory falsification‛ where witness confuses actual memories of events with events described
by media. Varendonck demonstrated to court children prone to suggestions and the suspect’s innocence.
Advocates of FP in NA. 1908 Hugo Munsterberg’s On the witness stand: argued psychology had much to
offer the legal system. Led heavy criticism from legal profession, psychology was ignored by the legal
profession for a long period of time. FP first established clinic for juvenile delinquents, began using
psychological testing for law enforcement selection purposes in 1917. landmark court cases in US. Driver
case: the court did not accept psychologist’s testimony that the raped girl was ‘moron’. Brown vs. Board of
education(1954): segregation of children leads to feeling of inferiority for black children, won the case. Jenkins
v US (1962): 3 psychologists support that the defendant has schizophrenia, court first dismissed them saying
they are not qualified to give expert testimony, then reversed the decision.
Psychological theories of crime. Psychoanalytic theories. Sigmund Freud’s followers. It is primarily dynamic
internal forces within people that account for their criminal behaviour, childhood events and experiences are
crucial for understanding crime. Many theories, one of them: John Bowlby’s theory of maternal deprivation,
argued that early separation of a child from his or her mother prevents effective social development from taking place, children experience long term problem in developing positive social relationship, develop
antisocial behaviour. This theory is based on study of juvenile delinquents. Learning theories. Based upon
principles of conditioning, which speculate that person’s behaviour, including criminal behaviour is learned
and maintained by its consequences. Criminal behaviour can be eliminated or reduced by modifying
consequences. One of them: social learning theory by Albert Bandura: learning from watching others in the
social environment and reinforcement contingencies. Observational learning through 3 primary contexts:
family, peer group and cultural symbols such as TV. Antisocial behaviour views as a function of his or her
exposure to antisocial behaviour on the part of others, especially when it is rewarded. Critics argue not all
those who grow up w/ antisocial role models turn criminal. Personality theories. Criminal behaviours is
primarily due to personality makeup, either developed or inherited. Biosocial theory of crime proposed by
Hans J Eysenck focuses on biological, social, and individual factors. # major dimensions: extroversion,
neuroticism and psychoticism, each fall a long a continuum. Individuals are born with cortical and autonomic
nervous systems, extravert seek out simulation, introvert avoid them. Neurotic have over reactive ANS,
strong reactions to unpleasant stimuli. E requires more stimulation, therefore, less responsive to negative
consequences. High N more difficult to condition as well. Thus high E and high N have strong antisocial
inclinations. Critique: no delinquents found in high E high N, can’t explain how all crimes emerge.
PF as a legitimate field of psychology: textbooks, journal articles, professional associations, APLS, CPA,
undergrad, graduate programs.
Modern day debates: Psychological experts in court. Functions of expert witness: provide court with
information that assists them in understanding a particular issue, and to provide the court with an opinion.
They are allowed to draw inferences from their observations, apart from regular eyewitnesses. They are there
as an educator for judge or jury, not as a advocate for defence or prosecution. The challenges of providing
expert testimony. Not an simple task b/c of the inherent differences exist between psychology and law. 7
different dimensions: 1. knowledge: cumulative research vs. legal precedent, logical thinking and case law. 2.
methodology: nomothitic (goal is to uncover broad pattern and general trends through use of controlled
experiments and statistical methods.) vs. idiographic (case by case basis). 3. Epistemology: uncover hidden
truth vs. truth based on most convincing story. 4. Criteria: cautious to accept something as true, need
replications vs. what is true based on a single case, more lenient criteria. 5. Nature of law: how people behave
vs. how people should behave. 6. principles: consider alternative explanations vs. convince judge and jury
that their explanation is correct. 7. latitude: psychologist limited behaviour vs. lawyers’ less restrictions.
Judges often can’t see how psychologist can help court proceedings. Criteria for accepting expert testimony.
General acceptance test: a standard for accepting expert testimony, which states that expert testimony will be
admissible in court if the basis of the testimony is generally accepted within the relevant scientific community.
Critics said there terms were too vague, more specific admissibility criteria were set. For scientific evidence to
be admitted to court, it must be provided by qualified expert, be relevant and be reliable (meaning
scientifically valid). Daubert criteria: it is valid if the research has been peer reviewed, testable, has recognized
rate of error, adheres to professional standards. SSC established the standard for admitting expert testimony
in Canada: the Mohan criteria: 1. the evidence must be relevant, 2 the evidence must be necessary for assisting
the trier of fact (must be beyond the common understanding of the court) 3. the evidence must not violate any
rules of exclusion (must not relate to whether a witness is telling the truth) 4. the testimony must be provided
by a qualified expert, which is typically determined through training, experience and research. #2 rely on the
discretion of judge, R v. McIntosh and McCarthy, eyewitness was common knowledge, therefore,
inadmissible. Chapter 2。Police psychology
Police selection. The use of valid police selection procedures allows police agencies to select applicants with
desirable traits. History: IQ and personality tests were used to predict police performance. LAPD tested using
the Humm-Wadsworth temperament scale. Testing were a standard procedure for selection. 1960/70s,
establish formal selection process, use of cognitive abilities and personality features, selection process become
formalized. Canadian agencies require background and medical checks, use a range of cognitive and
personality tests, slight differences across provinces.
Stage 1. Job analysis: define the knowledge, skills, and abilities of a good police officer. Psychologists conduct
survey methods and observational techniques to identify relevant KSAs. Problems: KSA might not be stable
over time, different PO characterized by different KSAs, KSA describe the ideal street level PO, not the same
as police administrator, individuals disagree with what KSA is important. Agreement on the KSA: honesty,
reliability, sensitivity to others, good communication skills, high motivation, problem-solving skills, and team
Stage 2. constructing and validating selection instruments. 2 goals: develop a selection instrument for
measuring the extent to which applicants possess KSA and to ensure that it relates to measures of police
performance (validation, aka predictive validity). Problem: how we measure police performance, variety of
measures as indicator of performance, none of them suggest that one measure is better than another, ratings
by different individuals are contradictory.
Validity of police selection instruments. Selection interview. Semi-structured interview, goal: determine KSA
present, ask about learning orientation, interpersonal skills, service orientation, personal effectiveness and
flexibility, thinking skills. Some research indicate validity, others problematic – mixed results. Inter-rater
reliability between interviewers is low. Psychological tests. Commonly used, some developed with police
selection, others are developed in other context, such as mental health. Useful in determining presence of
certain attributes. Cognitive tests: procedure for measuring verbal, mathematical, memory and reasoning
abilities. Eg RCMP police aptitude test, designed to evaluate an core skills that are considered essential, better
at predicting performance during training compared with future on job performance. Personality tests:
MMPI-2 used most often, moderate level of predictive accuracy because never developed to be a selection
instrument. IPI (Inwald personality inventory) developed specifically for law enforcement, measure stress
reactions, interpersonal difficulties and alcohol drug use, appear to be more predictable. Assessment centres:
a facility in which the behaviour of police applicants can be observed in a number of situations by multiple
observers. Primary selection instrument is the situational test: a simulation of real-world policing task.
Attempt to tap into KSA, 4 tests developed to test those skills, moderate level of predictability.
Police discretion: an policing task that involves discriminating between circumstances that require absolute
adherence to the law and circumstances where a degree of altitude is justified. PO do not always enforce law,
have great latitude to apply the law because it is impossible to establish laws that adequately encompass al
the possible situations an officer can encounter, a degree of discretion is inevitable. Also, if enforce all the
laws, will be in court all the time, vague law that do not have to be enforced all the time, some violations are
minor in nature, full enforcement would alienate public and overwhelm criminal justice system (prison).
Problem: discrimination/inappropriate discretion can occur.
Areas where police discretion is used at length. Youth crime. 30-40 handled by police informally thru
community service. Encouraged to use discretion because do not want them to interact with prisoners. Youth assistance program have a resolution conference where family coming together with victim and police in an
attempt to solve a problem (compensate, penalize, provide support and establish monitoring scheme), relies
on discretion of police (use it, is it working). Offenders with mental illness. Discretion used either to arrest,
psychiatric, or informal. Most of the times, dealt with informally, refer to psychiatrist, about 50% arrest.
Domestic violence. Transition from ignoring to arrest caused by cases against police and arrest has deterrent
effect, pro-arrest policies put in place and new laws. Arrest rates are 12-40, other options include mediation,
referrals, and separation. Use of force situations. Particularly use of lethal force, granted to use force to
protect public and self, but only to the extent of suppress the situation and accomplish goal. Can be very
costly, potential lawsuit. Vague terms (reasonable grounds) used in criminal code. Court will decide if police
action was inappropriate. Rarely incident and often a minimal amount of force is used.
Factors that influence police discretion. More likely to make an arrest if the crime is serious, evidence is
strong, victim asks, victim and offender are strangers, and suspect is resistant or disrespectful.
Controlling police discretion. Charter of rights and freedoms: everyone treated fairly and equally.
Development of administrative policies within police agencies that are specifically meant to control the use of
force by police officers. Departmental policies. Use of force restriction on NYPD to decrease use of lethal
force shown to be very effective. But other factors such as philosophies of an senior officer have impact as
well. The use of force continuum. Indirectly control use of force, make PO carefully assess before decision.
Make sure PO does not use excessive force, only enough to subdue resistance. The national use of force model
in Canada developed to represent the process by which a police officer assess, plan and respond to situations.
Police stress. Considered the most stressful job, exposed to many stressful events, have negative impact on
family and PO, organization. Sources of stress: common ones include organizational, occupational, criminal
justice, public stressors. Some believe organization strongly affect than occupational, OS most stressful
events. Some personality types contribute to stress as well: low confidence and optimism, high cynicism,
authoritarianism, type A personality increase stress.
Consequences of police stress. Acute stress can have serious long time consequences, stressors can affect PO
on chronic basis. Physical health problems: physiological breakdowns: cardiovascular disease, digestive
disorders, death rates due to cancer is higher. Limited research. Psychological and personal problems: PTSD,
drug, alcohol abuse, marital problems, suicide. Alcohol more problematic, burnout (mixed results). Job
performance problems: result of the two, impaired job performance include decreased efficiency, increased
absenteeism, early retirement. Form organizational perspective, very serious
Preventing and managing police stress. Programs include informal support networks, physical fitness,
counselling, family assistance. One strategy for training police officers to use effective coping strategies is
adaptive coping skills. Those who got the training performed better than control group. Has numerous
techniques for recognizing and reduce stress, how to communicate with other more effectively, disengage
from negative mental and emotional reactions by shifting attention. This can cause stress-related symptom
Chapter 3. psychology of police investigation
Police interrogation. Confession most likely to get prosecuted, but has to be backed up by evidence. Police
investigation is used to interview suspect for purpose of gathering evidence and obtaining confession. It is
inherently coercive, intimidating, gives police power over suspect. Before its more physical, now
psychological interrogation such as lying about evidence, imply threat and promise lenient punishment, view
them as necessary evil in order to obtain confession. Reid model of interrogation. 3 steps. Problems with it: require accurate deception detection, no one can be
very skilled at that, even trained PO, often lead to wrong accusations. Miranda rights protect individuals, but
sometimes police minimize it and innocent people waive those rights. Also investigator bias: result when PO
enters an interrogation already believing that the suspect is guilty, it can led to coercive and pressure-filled
interrogation that, in turn cause suspects to appear more defensive and guilty.
Interrogation practices and courts. Court looks at confession on two aspects: whether it was voluntary and if
the suspect was competent to provide the confession. Confession obtained using subtle psych is admitted to
court regularly. Recent changes to interrogation procedures: England forbid to use many techniques in Reid
model, use investigative interview, only gather information, not force confession. Practises of videotaping
interview more common
False confessions can lead to wrongful convictions. Retracted confession: declare confession made is false.
Disputed confession is a confession that is later disputed at trial due to legal technicalities or the suspect
disputes the confession was ever made. Frequency of false confession. No one knows how frequently it is
because it is difficult to determine false confession, but enough cases to treat the issue seriously. Different
types: voluntary false confessions arise due to a morbid desire for notoriety, person unable to distinguish fact
from fantasy, need to make up for pathological feeling of guilt by receivi