Mental Illness and Crime



Mental illness and crime are two concepts that can often be interrelated. However, it has still been an intense debate and study about their relationship, and they are correlated through various cases around the world. When the importance of mental health is advocated, the relationship between the perspective of crime and the prospective of committing a crime due to mental instability is discussed. Still, such a statement cannot amount to concluding that every mental illness leads to criminality.

In this paper, we are to discuss the interconnection between mental illness and crime and whether a mental illness stimulates criminality or it just serves as a factor in crime and such criminal behaviour, along with analysing some infamous crime cases where the criminals are diagnosed with mental illness and also discuss the kinds of mostly found mental illness in criminals and prisoners through the world.

What is a mental illness, or what amounts to a mental illness?

Mental illness is a psychological illness or mental health defect that includes or results in abnormal moods and emotions, a shift in perception and the act or behaviour of an individual. A person affected by a mental illness no longer views or behaves in a universal normal standard ( i.e. the standards set by the society ) due to their change in emotions and perspectives. Their social and private relations are affected, or they could not participate in such activity and be able to adapt or be productive or contribute to the society.

Some mental illnesses are not purely caused due to just psychiatric or psychogenic reasons, but they may also be caused due to physiological illnesses and like. Mental illness does not necessarily need treatment in some cases, but in severe cases, it can be treated with the help of a psychiatrist and psychologist, which may include medication, and psychotherapy along with changes in lifestyle like location change, sleep cycle exercise and nutrition intake.

Can mental illness amount to criminality?

When we talk about mental illness, we often bring in the concept of crime or criminality, which includes violence and/or illegal and irrational behaviour. The concept or the idea that a mentally ill person is violent or they are more prone to engage in violence and illegal activity is very prevalent in many classes of society globally. But this scope or view of society is very much a misconception. Most of the time, the victims of violence or abuse are the one affected by mental illness and such mental problems and can’t connect with the society; where even the society views them with tinted glass and judges them, which proves very harmful to the mentally affected individuals which in turn may serve as the very factor promoting crime or illegal actions.

But I do deny or completely cross out the possibility that a mentally ill person can be violent or may involve in crime. But there is no definite proof or any methods to predict if a mentally ill person can cause or commit a crime. Due to long-existing misbelief that associates crime and violence with mental illness, society still tantamount mental illness to criminality. Most of this misconception is due to false and misleading media releases and such news. Like most of the time, mentally ill persons are portrayed to be violent and aggressive in media.

Mental illness as a factor of crime or criminality:

A person with mental illness does not necessarily be a criminal, nor does a criminal must have a mental illness likewise. The concept of mental illness can be considered as one of the factors which cause crime or the genesis of criminal intentions but not the only main reason.

Here I advocate mental illness to be only a factor for criminality, and there is a highly likely chance of a drug-addicted, intoxicated and such but a completely sane person to commit a crime or engage in violent behaviour when compared to a mentally ill person. So mental illness does stipulate whether someone will break the law or commit a crime but rather the intentions of the individuals themselves.

In many cases, through the world, many criminals are diagnosed with mental illness and are suffering without proper help and even in some cases due to inadequate knowledge and exposure to the concept of mental health and mental illness and ways in handling these cases, such lawbreakers are sent to prisons, and no help has been provided in nursing their mental health. Like here, many prison populace has a mental illness like borderline personality disorder, antisocial personality disorder, schizophrenia, etc., but the very idea that an antisocial personality disorder and such are even a severe mental illness is a very debatable topic.

Few common mental illnesses found in criminals:

Here, some of the most common illnesses found in the criminals are listed, along with some infamous criminals with these issues. Still, it is stressed again that not all people with this mental illness are prone to violent behaviour or crime and criminal activity; only a tiny fraction of people with mental illness engage in crime and illegal activity.

Schizophrenia :

Schizophrenia is a condition of a person who perceives reality abnormally; they have persistent delusion and hallucination and a loss of sense of control like they do certain acts without their control impulsively and a sense of passivity, etc. They experience irrational and disorganised thinking and behaviour like bizarre and unpredictable emotional reactions and inappropriate responses, and loss of thinking skills and memory, which interfere with normal social life. They also undergo heavy negative emotions like lack of enthusiasm in everyday work, become socially withdrawn, and become unable to express any emotions, which interferes with relationships with family, friends, and anybody. They will always be agitated and make mistakes in work and conversations and in some cases, are in constant fear and suicidal to get relief.

James Holmes is a mass murderer who killed 12 people and injured 70 people in the premier of the batman movie. He was diagnosed with schizophrenia by 20 doctors. He was still found guilty since he did his actions, knowing it would cause death even if he had a mental illness.

Borderline personality disorder :

A borderline personality disorder is a mental illness where an individual has a fear of abandonment, rejection and such where have frequent switch in attitude towards others, like having a good impression on someone and suddenly despising them within some time. They have low self–esteem, sees themselves as flawed and have unstable identity issue where they have trouble setting up and following a clear goal in life. They suffer from paranoia and risky behaviour with no proper sense of reality with varied mood swings. In some cases, there are feeling of emptiness and aggression along with suicidal and self-harming actions.

Katherine knight is criminal diagnosed with borderline personality disorder. She killed her de – facto husband after he refused to marry her; she stabbed him 37 times and skinned his body and hung it in the hallway and made a stew out of his meat, and was ready to serve it to his two grown kids, later when she was interrogated she claimed to have no memory of this incident. She was the first Australian woman to be given a life sentence without parole.

Antisocial personality disorder or Psychopathy :

Like some mental illnesses, the cause for anti–social personality disorder is not clear or hard to conclude since there are various factors which could lead to it, like drug addicting, a victim of abuse, etc., an antisocial personality disorder is a mental illness where an individual has a completely different view of the world when compared to normal global standards. They have no sense of right or wrong, more like disregard it, and are very aggressive and destructive towards people, animals and property. Mostly they are pathological liars who are manipulative and use their charm and abilities for personal gains and a sense of achievement. They have a sense of superiority and are narcissistic, that is, too much self-love, and they use their wit only for selfish purposes. There is a severe lack of empathy for other people and living organisms, and they will repeatedly violate the right of others and are very irrational in risk-taking behaviour and fail to consider and doesn’t care about the consequences their actions may bring to other people. It was mostly diagnosed in most infamous serial killers and criminals.

John Wayne Gacy, also known as ‘ killer clown ‘, killed more than 30 young males and teenagers and disposed of them in the garage and threw them off in the lake and such. He was diagnosed with an antisocial personality disorder, but he was held to be guilty and was executed death sentence by lethal injection.

Bapu @ Gajraj Singh vs State of Rajasthan

Section 84 of the Indian penal code has provided that “Nothing is an offence which is done by a person who, at the time of doing it, by reason of unsoundness of mind, is incapable of knowing the nature of the act, or that he is doing what is either wrong or contrary to law.”

Section 84 of IPC provides mental illness as a defence that is in the case where the person is of unsound mind and is completely incapable of knowing right or wrong and the nature of their actions and the result it would bring about. The accused must not have men’s rea, which is a clear intention and reason for law-breaking action.

In a Supreme Court case with a bench comprising Justices Arijit Pasayat and D K Jain, it was held that a mere mentally ill person, that is psychopathic, delusion or such cannot get protection or defence on the ground of section 84 of IPC, under unsoundness of mind unless he is completely incapable of knowing the nature of his actions and result as the burden of proof of insanity or unsoundness of mind lies with them.


From the above the relation between mental illness and crime, it can be concluded that it is quite a debatable topic where it is hard to conclude whether the action of crime has stemmed from mental illness or whether mental illness and crime are completely unrelated. But from the above discussion, we can summarise that mental illness serves as one of the factors for crime or criminality and the reason in only very few cases. Even in the case of mental illness, a person cannot escape the law in the case of severe or grievous crimes and are aware that their action may result in harm or lawbreaking.


Bapu @ Gajraj Singh vs State of Rajasthan

Indian penal code, 1860

Note :The author is a Law Student. Views are personal and for educational purposes only.

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