Mental Illness and Criminal Insanity

Paper Info
Page count 6
Word count 1664
Read time 6 min
Topic Law
Type Research Paper
Language 🇬🇧 UK

By Reason of Insanity

The topic of the insanity defense as it pertains to the broader sphere of mental health is widely controversial. There is a misconception that the existence of a severe mental health issue by itself can make a legal determination and thus be useful in defending an individual in court. What this perspective fails to understand is that just because, for example, a defendant has been diagnosed with bipolar disease, he or she can be deemed insane and issue the insanity defense as a vehicle for a plea deal or even exoneration.

For the argument based on insanity to hold up, it is imperative to ensure that an individual was not in the mindset at the time of the offense specifically. Therefore, just because a perpetrator was showing signs of severe mental distress after the crime took place, it does not mean that he or she was in the same state at the time when offence was committed. Thus, the aim of this paper is exploring the issue of insanity as a broad mental health topic and apply the findings to defense by reason of insanity, which is widely debated within the criminal law narrative.

Understanding Insanity

The term “insanity” is now considered medically obsolete in terms of defining mental disorder and derangement. In the health sense, insanity refers to the mental illness of a severe nature in which a person cannot differentiate between reality and fantasy, cannot commit to responsibilities due to psychosis, as well as being uncontrollable due to impulsive behavior (“What’s insanity defense?,” 2012). However, this definition is rarely used as the term is predominantly involved in the discussion of distinguishing between guilt and innocence in court.

Besides, there is no such diagnosis as “insane” when referring to the Diagnostic and Statistical Manual of mental disorders, fifth edition (DSM-5). As of now, insanity represents a legal term that denotes the condition because of which an individual is considered to have limited responsibility for the act of crime. The lack of knowledge and awareness regarding what it means to be insane causes a high degree of exploitation of vulnerable individuals and the perpetuation of negative stereotypes.

Insanity Defense

One of the most notable stereotypes is associated with the not guilty plea by reason of insanity (NGRI) in criminal investigative procedures. NGRI is applied when a person committing severe crimes uses mental disorders as a method of defense. The widely misunderstood condition is therefore used “as a scapegoat for their immoral actions,” to quote Raimonde (2016, para. 2) for Huffington Post.

One of the examples of defendants using insanity as a justification of their actions is Dimitrios Pagourtzis, who was accused of killing two teachers, eight students, and injuring thirteen others in the Santa Fe High School shooting on May 18, 2018 (FOX 26 Houston Staff, 2019).

The intention of the perpetrator’s attorneys to raise the insanity defense in the capital murder trial implied that during the shooting, Mr Pagourtzis was influenced by severe mental distress that prevented him from having sound judgement of the situation and thus proceeded with the crime without being able to differentiate between reality and fantasy.

In defense of the school shooter, the insanity argument would only hold up if the mental health evaluation of the person as well as the cross-examination of the defense experts came to the same finding regarding the defendant’s mental state. In either case, to determine “whether or not the defendant was insane at the time of the offense,” the state prosecutors are entitled to present their own experts for interviewing, unbiased testing, and examining the defendant (FOX 26 Houston Staff, 2019, para. 4).

Given the wide application of NGRI pleas in criminal cases, it is imperative to shed light on what it means for individuals to be mentally ill as well as determine what persons diagnosed with mental illness are capable of doing.

Those criminals who claim mental health disorders to be reasons for their acts usually have a distorted perspective on what it truly means to be mentally ill. As quoted by Raimonde (2016) for Huffington Post, investigative research conducted by Louis Theroux for BBC named By Reason of Insanity found that approximately 90% of individuals diagnosed with various mental health illnesses are not harmful and therefore do not exhibit any inclinations for violence.

Furthermore, people typically experience mental illnesses in various forms and different extents, and violence is an extremely minor component of one’s struggles (Raimonde, 2016). Because of this, proving that a person committed a crime just because he or she was mentally ill is a manner of severe expert rigor, which must be evidence-based.

Thus, if to consider the finding that 90% of mentally ill individuals do not act violently, it can be suggested that violence can take place only in severe instances of mental illness as well as in those that are not handled appropriately through therapy and medication. Therefore, it may seem that an ideal set of circumstances for violent crimes due to insanity must involve an untreated and severe mental illness (Minero, Barker, & Bedford, 2017).

Although, this does not show that the rare cases of extreme mental illnesses that have not been appropriately treated and subsequent violence should be ignored as individuals struggling with it can lose the ability of distinguishing between reality and imagination.

Importance of Forensic Psychology

Since it is possible that a person can temporarily lose the ability to differentiate between right and wrong, proper evaluation and psychological analysis are necessary to determine whether the perpetrator’s “moral compass” has been compromised. Moreover, there is a likelihood of genuine moments of insanity being associated with fear, guilt, anger, and other negative emotions that contribute to crimes being committed.

Therefore, there is only a limited number of individuals requiring care in a mental health facility instead of being incarcerated. Although, according to Raimonde (2015) for the Huffington Post, this group of people can be involved in criminal cases, but it does not constitute a majority.

Furthermore, as found by Louis Theroux in By Reason of Insanity, less than 1% of criminals who pleaded not guilty by reason of insanity are actually acquitted while 70% of them ultimately retract the plea (as cited in Raimonde, 2015). This knowledge suggests that an insanity plea is more often as a method of avoiding imprisonment instead of a sign for urgent mental health care. Furthermore, people suffering from severe mental health conditions are most likely not violent but are misunderstood and mistreated, with them being 2.5 times more likely to become victims themselves (Raimonde, 2015).

The role forensic psychologists in criminal cases that involve mental illness as a part of defense is fundamental for making a fair judgment on each case. In their evaluations, psychologists consider the American Psychological Association (APA) Guidelines intended for compiling extensive historical data on a defendant as well as his or her thorough neurological and physical examination (American Psychological Association, 2020).

It may also be necessary to conduct diagnostic studies, appropriate brain scans, genetic and blood studies, as well as consultations with independent mental health specialists. Those involved in the assessment of defendants’ mental state must have the training and clinical skills to recognize the psychiatric, neurological, or congenital conditions that could affect both the development and behavior of defendants at a particular time.

Forensic psychologists will also help the court understand the mitigating circumstances of the crime as related to mental health issues. In order to do so, substantial evidence of mental health complications is needed, considering the totality of a defendant’s life and character. This could help in determining either reducing or extenuating degrees of moral culpability for the crime being committed. Moreover, forensic psychologists will gather information on mitigation that would include environmental, biological, and familial factors, all of which could act as determinants for an individual’s psychological state.

Only after a rigorous investigation and the gathering of reliable information for mitigation can a defendant use insanity as a reason for acquittal. Overall, the insanity defense is still much overused in the legal system, which perpetuates stereotypes that affect truly mentally ill individuals who may not be violent at all.

Concluding Remarks

The insanity plea is a misunderstood and stigmatized issue in the criminal justice system. The current exploration has shown that the matters are not as “black and white.” Without a rigorous expert-based evaluation of defendants’ psychological states at a specific time of the crime, it is impossible to claim that a person could be characterized as insane and thus may not be convicted.

Every person is unique, and so are the crimes that can be committed, which is why it is imperative not to assume that those prosecuted from a crime are mentally ill overall. This can lead to a misrepresentation of a vast majority of peaceful individuals who are seriously mentally ill and deal with the implications of their diagnosis on a regular basis. Although, one should not eliminate the possibility that some criminals may lose touch with reality and could be classified as insane at the time of crime being committed.

The complexity of the problem lies in the fact that one cannot say for sure whether a person is insane or what he or she was feeling when committing a crime. While some may truly lose their connection with reality, others can use the insanity plea as a defense for deliberate acts of crime. Thus, the problem requires further research because mental illness continues to be affected by stereotypes.

It is high time for researchers to delve into the issue deeper and determine what it truly means to be mentally ill at the extent to which the diagnosis can be a viable defense in court. Not all people who suffer from mental illnesses are criminals, and not all defendants in court can use mental illness as a justification for their action. Furthermore, the problem lies in the fact that more mentally ill individuals are victims of crime rather than criminals themselves.


American Psychological Association. (2020). Specialty guidelines for forensic psychology. Web.

FOX 26 Houston Staff. (2019). Insanity defense raised for Santa Fe High school shooting suspect. FOX 26 Houston. Web.

Minero, V. A., Barker, E., & Bedford, R. (2017). Method of homicide and severe mental illness: A systematic review. Aggression and Violent Behavior, 37, 52-62.

Raimonde, L. (2015). Mental illness and criminal insanity: Is there a link? Huffington Post. Web.

What’s insanity defense? (2012) [Video file]. Web.

Cite this paper


NerdyHound. (2022, May 23). Mental Illness and Criminal Insanity. Retrieved from


NerdyHound. (2022, May 23). Mental Illness and Criminal Insanity.

Work Cited

"Mental Illness and Criminal Insanity." NerdyHound, 23 May 2022,


NerdyHound. (2022) 'Mental Illness and Criminal Insanity'. 23 May.


NerdyHound. 2022. "Mental Illness and Criminal Insanity." May 23, 2022.

1. NerdyHound. "Mental Illness and Criminal Insanity." May 23, 2022.


NerdyHound. "Mental Illness and Criminal Insanity." May 23, 2022.


NerdyHound. 2022. "Mental Illness and Criminal Insanity." May 23, 2022.

1. NerdyHound. "Mental Illness and Criminal Insanity." May 23, 2022.


NerdyHound. "Mental Illness and Criminal Insanity." May 23, 2022.