Criminal Behaviour, Mental Health & The Insanity Defence

Dr. Clare-Ann Fortune, PSYC335, 2025.
Reading: Sixiao Sunny Li & Susan Hatters Friedman (2015). Moral wrongfulness and insanity: A New Zealand sample. The Journal of Forensic Psychiatry & Psychology, 26(5), 686-698.
Outline:
- Introduction
- Media representations
- Criminal behaviour & mental health
- Mental health & the courts
- Insanity Defence

Media Representations

Based on media portrayals, the public may receive certain messages about individuals with criminal behavior and mental health issues.
US research:
- John Monahan (1992) cites Gerbner, et al., (1981) found on prime-time TV:
  - $73\%$ individuals characterized as having mental disorders also displayed some violent behavior
- Shain & Philips (1991):
  - $86\%$ of all print stories dealing with ‘former mental patients’ focused on violence (Bartol & Bartol, 2009).
Media often portrays psychotic killers going on killing sprees, making it sensationalist, frightening, and vaguely entertaining but these are rare events.

Offenders, Mental Health & Intellectual Deficits

Overrepresentation of mental health disorders in prisons.
Inmates may benefit from treatment, regardless of having a serious mental disorder.
It's unclear if disorders were present before or after incarceration.
Some specific disorders are more strongly associated with criminal conduct:
- Schizophrenia
- Paranoid disorders
- Mood disorders
- Antisocial personality disorder

Schizophrenia

Often expressed through bizarre behaviors.
Can impact thought patterns, emotions, and perceptions.
Can be socially withdrawn, disorganized (e.g., speech), have poor self-care & disconnected from reality.
Inappropriate or flat emotions.
Delusions – false beliefs
- Persecutory delusions are especially problematic.
Hallucinations – sensing or perceiving things that others cannot.
- e.g., hearing voices
- Command hallucinations are especially problematic.
Represent small number of offenders.
Combination of schizophrenia & substance abuse/dependence increases risk (Serin et al., 2011).

Paranoid Disorders

Usually reasonably believable & not completely far fetched.
e.g., police watching them or neighbors spying on them.
Bizarre beliefs would fit into schizophrenia.
Often include persecutory beliefs about being spied on, cheated, conspired against, followed, drugged, harassed, etc.
Often highly suspicious (general or specific to an individual).
Can experience anger, resentment & even violent behavior due to beliefs.

Mood Disorders

Serious depression
- e.g., slowed down, feeling worthless, suicidal ideation, despair, etc.
Sometimes associated with delinquency in adolescent (females in particular).
May care less about personal safety & consequences.
Likely to have role in some events such as mass murders, school shootings, workplace violence & ‘suicide by police’.

Antisocial Personality Disorder

Pervasive disregard for & violation of the rights & wishes of others & social norms.
Includes irritability, irresponsibility, impulsivity, deceitfulness (e.g., lying, conning others), lack of remorse/empathy, callous.
Have difficulty maintaining relationships.
Prevalence
- Approx. $1-3\%$ of general population
- Approx. $30-50\%$ (even higher) of inmates
- More common in males than females.

Violent Acts

The majority of people with mental disorders do not commit serious or violence offenses
Males with mental disorders and a history of violent acts have a higher probability of further violence
Those with schizophrenia may be at higher risk of violent offending
Those at higher risk have schizophrenia, are male & have early onset of antisocial behaviour
Affective (mood) psychosis usually less violent but if they are violent they are often women with intent to commit suicide & kill people close to them
Factors ranked based on strength of relationship to violence (Elbogen & Johnson, 2009):
- Young age
- History of any violent act
- Male
- History of juvenile detention
- Divorce or separation in the past year
- History of physical abuse
- Unemployment in the past year
- Co-occurring severe mental illness & substance use
- Victimisation in the past year(From Serin et al., 2011)

Summary

As a group people with mental disorders are no more likely to commit crimes (incl. violent acts) than those without a mental illness
Some disorders (e.g., schizophrenia, paranoid disorders, mood disorders & APD) are more often associated with criminal conduct
But not all individuals with these disorders will engage in criminal conduct
Only applies to those with current symptoms
Phase of the illness may make a difference
Relationship between mental illness & crime is complex
Confounding variables
Mental disorder & violence link applies to only a small minority (e.g., schizophrenia) & is stronger when they have a history of violent behaviour
Link between violence & schizophrenia
- Only true for small group of those with schizophrenia
Link between violence & mental illness & substance use is greater

Mental Health and The Courts

Roots in common law tradition
Concept has developed over time
Not guilty by reason of insanity:
- Philosophical tradition
- Understanding right from wrong
Remember: Fitness to stand trail - concerned with:
- Procedural fairness
- An individual’s ability to defend themselves against their accusers
- The process which evaluates their competence to stand trail

Insanity Defence

Foundation in English law
M’Naughton Rule
- Being aware & knowing what one was doing at the time of illegal act
- Knowing or realising right from wrong in a moral sense
Actus reus – criminal act
Mens rea – criminal intent
Rare in NZ & elsewhere (e.g., UK & US)
Crimes Act 1961 in NZ (s 23)
Assumed sane until proven otherwise
Not convict if found to be:
- …labouring under natural imbecility or disease of the mind to such an extent as to render him [sic] incapable of
  - Understanding the nature & quality of the act or omission
  - Knowing that the act or omission was morally wrong (with reference to normal standards of right & wrong)
Procedure when plea entered is set out in s 20 of CP(MIP)
Key concern is state of the individual at the time of the alleged offence
It's about criminal responsibility
Insanity is not relevant if the individual is found unfit to plead, as must be fit to plead
Often get public exposure but very small number
In the US they are estimated to be used in about $1\%$ of felony criminal cases
NZ - evaluated in less than $2\%$ reports (Li & Hatters Friedman, 2016)
Often not pleaded successfully ( $\approx 10-30\%$ internationally)
NZ study: $60\%$ found legal insane (Li & Hatters Friedman, 2016)
Most commonly due to:
- Schizophrenia
Other common characteristics of individuals found legally insane
- Prior psychiatric hospitalisation
- Prior criminal histories
- Predominantly violent offending
- Finished high school
- NZ study found limited education (Li & Hatters Friedman, 2016)
- Under influence of substances at time
Being found not guilty by reason of insanity does not mean they will go free
In NZ they may be sent to:
- secure forensic hospital, prison, community care, supervision, home detention, or released
Legislation provides little guidance for mental health professionals
Clinical and legal definitions similar but vary
Clinicians can give opinion
Expected to do this in dispassionate, unbiased way
Better if focus on state of mind on the day of the event in the weeks immediately preceding it
High level of agreement between clinician’s opinion and courts decision (Li & Hatters Friendman, 2015)
- $81\%$ for NGRI
- $74\%$ found sane
Fitness to stand trial
- Focus is competency at time of Court procedures
Not guilty by reason of insanity
- Is about capacity for criminal responsibility at the time the alleged offence occurred
Insanity as a plea is irrelevant if found unfit to plead
Complex presentations
Complex task for clinician
Interface between mental health and law