March 1981. John Hinckley Jr. attempted to assassinate US president Ronald Reagan in order to gain the attention of the actress Jodie Foster, with whom he was obsessed. Hinckley’s attorney argued that he suffered from schizophrenia. The verdict? Not guilty by reason of insanity. He was institutionalised in a psychiatric facility where he spent more than three decades. This is just one example of a case where the insanity defence was used. But how exactly does it work? And is it always successful? Let’s find out!

This article will cover:

·       What is insanity defence?

·       The psychological profiles of the defendants

·       Malingering

·       Controversies and misconceptions surrounding the insanity defence

What is insanity defence?

Under specific circumstances, people accused of a crime can plead guilty by reason of insanity. This is officially referred to as the insanity defence. It can be used when, at the time of the crime, the defendant was not able to differentiate right from wrong due to suffering from a mental illness or another kind of mental defect [3]. Most crimes require the so-called ‘mens rea’, i.e., the intent to commit a crime [8]. In the case of the insanity defence, the attorney argues that at the time of the crime, the defendant was in such a mental state that did not allow them to tell right from wrong. In other words, they did not intend to harm the person because they did not realize that their actions would cause harm.

Alternatively, some states have adopted a ‘guilty but mentally ill’ verdict [5]. This is essentially the same as being found guilty but the defendant might be required to undergo treatment while in prison. Similarly, the concept of diminished capacity means that the person was not able to form the intent that is required for the crime [5].

Moreover, it is important to keep in mind that the term ‘insanity’ is legal, not psychological [12]. A person cannot be diagnosed as ‘insane’. However, if the defendant is found not guilty by reason of insanity (NGRI), they are sent to a treatment facility rather than prison [4]. The assumption is that because the defendant does not understand the severity of their actions and/or is not able to control their actions, it is possible that they will commit the crime again after being released from prison. Therefore, treatment is preferred over punishment.

Types of insanity defence:

There is always a presumption that the defendant is sane and thus they must provide substantial evidence of their ‘insanity’ [12]. Depending on the country or jurisdiction, the courts use one or more of these four rules to determine legal insanity [5, 6, 7].

1. The ‘M’Naghten Rule’ – Defendant either did not realise what they did or failed to distinguish right from wrong due to mental illness or defect (schizophrenia, psychosis, paranoia, etc.). Emphasis is on cognition because it focuses on the defendant’s awareness of their actions rather than the control over them.
2. The ‘Irresistible Impulse’ – In this case, the defendant must prove that they are suffering from mental illness and that this mental illness led to the inability to control their actions.
3. The ‘Durham Rule’ – Defendant’s mental illness led them to commit the crime (focus is on direct causality between mental illness and crime).
4. The ‘Model Penal Code’ – Due to a diagnosed mental disorder, the defendant lacks substantial capacity to understand the criminality of their actions and/or was unable to act within the confines of the law. Generally, it is easier to prove ‘insanity’ under this rule because it does not require a complete inability to understand one’s actions.

Psych profiles of NGRI defendants

Packer [13] investigated differences between ‘sane’ and ‘insane’ murderers and found that the NGRI group was significantly more likely to be hospitalised at least once prior to the crime. Moreover, the most common diagnosis among the NGRI group was paranoid schizophrenia. Similarly, the study by Holoyda et al. [9] found that the majority of the participants who were found NGRI had a primary diagnosis of a psychotic disorder. Other mental disorders that are associated with insanity defence include bipolar disorder or major depressive disorder. On the other hand, diagnoses such as personality disorders or paraphilias are usually not sufficient for insanity defence [1].

How is insanity assessed?

Standard evaluation by a forensic mental health professional (FMHP) is necessary [12]. This can be either a forensic psychologist or a psychiatrist. It is crucial to look at the history of mental illness as well as to determine the mental state of the defendant at the time of the crime [10, 12]. Ideally, they should assess the defendant’s behaviour, emotional state, cognition and perception prior, during and immediately after the crime. They must also establish the relationship between the mental disorder and the crime. However, it is not up to the FMHP to decide whether the person can be considered insane or not. That is up to the jury/judge to decide.

Unfortunately, it is not always easy to correctly assess a defendant’s mental state at the time of the crime because these assessments often take place weeks or months after the crime. Additionally, FMHPs also have to deal with the issue of malingering.

Malingering

Malingering refers to a purposeful production of false psychological symptoms with the goal of receiving a reward [1]. In the case of the insanity defence, the reward would be not being found guilty for the crime. Regardless of the disorder being faked, malingering is difficult to identify. However, there are situations in which the psychologist/psychiatrist should be especially careful and aware of the possibility of malingering. These include:

1.     When evaluating criminal defendants.

2.     Marked discrepancy between the individual’s claimed stress or disability and the objective findings and observations.

3.     Lack of cooperation during the diagnostic evaluation.

4.     The presence of antisocial personality disorder.

Controversies and misconceptions surrounding the insanity defence

·       Despite popular belief, the insanity defence is used quite rarely (less than 1% of crimes) and is successful only in around a quarter of those [10].

·       Personal feelings of the legitimacy of insanity defence or the insanity of the defendant may influence jurors’ decision making. Thus, better training and education is crucial [11].

·       Experts can have differing opinions → Sometimes the prosecution’s experts seem to argue that the person was fully aware of committing a crime while the defence experts support the insanity plea [10].

·       The quality of the mental institutions and treatment → NGRI defendants tend to spend more time in the facilities than patients suffering from the same illness who have not been accused of a crime. This raises the question of whether treatment rather than punishment is really the goal. Moreover, sometimes defendants spend more time in the treatment facility than they would in prison if they have been found guilty [10].

Many scholars argue against the idea of abolishing the insanity defence. However, they argue that reform is necessary in order to achieve less biased decision making and better quality of treatment.

Extra resources:

1. Movie ‘Primal Fear’

2. YouTube video – What Does Not Guilty By Reason Of Insanity Mean? https://www.youtube.com/watch?v=20H0yGx__NA

3. Article on cases in which insanity defence worked https://www.businessinsider.com/cases-where-the-insanity-defense-worked-2012-8?r=US&IR=T#from-one-crime-to-another-8

References

1. Adjorlolo, S., Chan, H. C. O., & DeLisi, M. (2019). Mentally disordered offenders and the law: Research update on the insanity defense, 2004–2019. International journal of law and psychiatry, 67, 101507.

2. American Psychiatric Association. (2013). Diagnostic criteria and codes. Diagnostic and statistical manual of mental disorders (5th ed.). Arlington, VA.

3. Chiacchia, K. B. Insanity Defence. Retrieved October 15, 2021 from https://psychology.jrank.org/pages/336/Insanity-Defense.html

4. Criminal Defense Lawyer. Pleading Insanity in a Criminal case. Retrieved October 15, 2021 from https://www.criminaldefenselawyer.com/resources/criminal-defense/criminal-defense-case/pleading-insanity-a-criminal-defense-case

5. Criminal Law. Insanity Defence. Retrieved October 15, 2021 from https://courses.lumenlearning.com/suny-criminallaw/chapter/6-1-the-insanity-defense/

6. Feuerstein, S., Fortunati, F., Morgan, C. A., Coric, V., Temporini, H., & Southwick, S. (2005). The insanity defense. Psychiatry (Edgmont (Pa. : Township)), 2(9), 24–25.

7. Find Law. (January 2019). Insanity Defence. Retrieved October 15, 2021 from https://www.findlaw.com/criminal/criminal-procedure/insanity-defense.html

8. Find Law. (February 2019). Mens Rea – A Defendant’s Mental State. Retrieved October 15, 2021 from https://www.findlaw.com/criminal/criminal-law-basics/mens-rea-a-defendant-s-mental-state.html

9. Holoyda, B. J., McDermott, B. E., & Newman, W. J. (2018). Insane sex offenders: psychiatric and legal characteristics of sexual offenders found not guilty by reason of insanity. Journal of forensic sciences, 63(4), 1207-1214.

10.  Knoll IV, J. L., & Resnick, P. J. (2008). Insanity defense evaluations: Toward a model for evidence-based practice. Brief Treatment and Crisis Intervention, 8(1), 92.

11.  Maidman, B. R. (2016). The legal insanity defense: Transforming the legal theory into a medical standard. BUL Rev., 96, 1831.

12.  Math, S. B., Naveen Kumar, C., & Moirangthem, S. (2015). Insanity defense: Past, present, and future. Indian journal of psychological medicine, 37(4), 381-387.

13.  Packer, I. K. (1987). Homicide and the insanity defense: A comparison of sane and insane murderers. Behavioral sciences & the law, 5(1), 25-35.