Forensic Psychology & Crime Theories: Key Concepts and Court Procedures

Biological theories of crime

Crime is linked to physiological/genetic factors such as chromosomal irregularities, lead exposure affecting brain development, and poor frontal lobe functioning.

Sociological theories of crime

Crime results from social factors, such as Merton's strain theory, Sutherland's differential association, and Becker's labelling theory.

Psychological theories of crime

Individual differences in personality and cognition (e.g., Eysenck's biosocial theory) increase antisocial tendencies.

Forensic anthropology

A forensic discipline that involves the identification of human skeletal remains.

Forensic linguistics

A forensic discipline that involves the analysis of language and its relation to legal issues.

Forensic odontology

A forensic discipline that involves the study of dental records and bite marks.

Forensic pathology

A forensic discipline that involves the investigation of cause of death through autopsy.

Forensic entomology

A forensic discipline that uses insect life cycles to estimate time of death.

Myths about forensic psychology

Myths include: (1) Forensic psychologists mainly do profiling, (2) TV shows portray it accurately, (3) All work with offenders, (4) It is only clinical, (5) It is a new field.

Appellant

The party who initiates an appeal, asking a higher court to review a lower court's decision.

Respondent

The party who opposes the appeal and responds to the appellant's arguments.

Justification defence

The accused admits the act but argues it was right under the circumstances (e.g., self-defence).

Excuse defence

The accused admits the act was wrong but claims they should not be held fully responsible (e.g., NCRMD, duress, intoxication).

Negating the actus reus

Showing the accused did not voluntarily commit the act (e.g., automatism, accident).

Negating the mens rea

Showing the accused lacked the required intent (e.g., honest mistake, diminished capacity).

Admissibility of evidence

Whether evidence can be legally presented in court.

Weight of evidence

The degree of importance the judge or jury gives to the evidence once admitted.

Mr. Big technique

An undercover Canadian police procedure where officers pose as criminals and require a confession for gang acceptance; later used in court.

PEACE model of interrogation

A non-coercive, information-gathering method (Planning & preparation, Engage & explain, Account, Closure, Evaluation).

Retracted confession

A confession that the confessor later claims is false.

Disputed confession

A confession challenged at trial, not necessarily false.

Compliance in false confessions

Going along with demands of authority figures, even without true belief in guilt.

Internalization in false confessions

Accepting guilt for an act one did not commit.

Confabulation in false confessions

The act of fabricating, distorting, or misinterpreting memories about the details of the confession.

Polygraph disclosure tests

To elicit admissions from offenders rather than directly detect lies.

Brain-based deception research

Using brain activity (ERPs, fMRI) to identify differences when lying vs telling the truth.

ERPs

Brain responses to stimuli, measured by EEG, used to detect concealed knowledge.

P300 response

An ERP component that occurs when recognizing meaningful information; used in guilty knowledge tests.

fMRI research on deception

Identifies brain regions activated when lying (e.g., prefrontal cortex involvement).

Brain imaging evidence

Jurors were more persuaded by cases with brain-imaging evidence, even if the science was weak.

Truth-bias

People are more likely to believe others are telling the truth, leading to poor lie detection.

Lie detection accuracy

Police officers and laypersons are generally poor at distinguishing truths from lies, with accuracy rates just above chance.

Conversion disorder

Neurologic symptoms not intentionally produced and without external incentives.

Factitious disorder

Intentional production of symptoms with no external incentive.

Munchausen syndrome by proxy

A caregiver induces illness in another (often a child) to gain attention.

Malingering

Intentional faking of illness for external gain.

Key components of malingering

(1) Intentional production of false symptoms, (2) Motivation for external gain.

External motivations for malingering

Avoiding criminal responsibility, evading military service, obtaining drugs or financial compensation.

Prevalence of malingering in forensic contexts

Estimated at about 10-20% in forensic assessments.

Defensiveness

The tendency to minimize or deny psychological problems, the opposite of malingering.

Rogers's pathologic model of malingering

Malingering is a product of mental disorder.

Rogers's criminological model of malingering

Malingering is linked to an antisocial personality and lack of cooperation.

Rogers's adaptation model of malingering

Malingering arises from a stressful situation where lying is seen as the best option.

Simulation design in malingering research

People are instructed to fake a disorder to study malingering.

Known-groups design in malingering research

Compares genuine patients with identified malingerers.

Indicators of malingered psychosis

Atypical hallucinations, endorsement of rare symptoms, inconsistencies between reported and observed behaviour.