When Can A Defendant Win An Acquittal On Grounds Of Insanity?

December 23, 2021

When Can A Defendant Win An Acquittal On Grounds Of Insanity?

You might have heard about an accused pleading for acquittal on grounds of insanity. This is a very popular defence strategy that lawyers sometimes use. It is based on the law that the punishment can be justified only if the defendant is capable of controlling his or her behaviour. To be convicted, an individual should understand that what he or she has done is wrong.

Individuals suffering from a mental disorder are not capable of knowing or choosing right from wrong. Hence, the insanity defence prevents such individuals from being criminally punished.

However, despite its ancient origin, the insanity defence remains controversial. Critics have always pointed out that a person killed by an insane person is just as dead as a person killed by someone who is sane. They argue that people with mental disorders should be punished for the harm they have caused.

In addition to this, over the years, questions have arised regarding the ability of psychiatrists, judges, and jurors to determine whether a person suffers from a mental disorder or not.

Also Read: When Should You Hire A Criminal Defence Lawyer?

Not Guilty By Reason Of Insanity

Even though acquittal on grounds of insanity is a popular defence strategy it is not a common defence strategy. Defendants rarely enter pleas of not guilty by reason of insanity. Moreover, on the few occasions when this plea is made, judges and jurors rarely support it.

The reason behind this is that neither the legal system nor psychiatrists have ever agreed on a single meaning of insanity. As far as criminal law context is concerned, various definitions are employed.

The most common definition used in criminal law is the McNaghten rule. It defines insanity as the inability to distinguish right from wrong. In addition to this, there is a common test, known as an irresistible impulse, which is used to test the mental state of the offender. The test is based on the fact that a person who acts out of an irresistible impulse knows that an act is wrong, but because of mental illness, cannot control his/her actions.

Defence Of Mental Disorder According To Canada’s Criminal Code

Although the Canadian Criminal Code does not define insanity, it does describe how the defence of mental disorder works. The code states:

16 (1) No person is criminally responsible for an act committed or an omission made while suffering from a mental disorder that rendered the person incapable of appreciating the nature and quality of the act or omission or of knowing that it was wrong.


(2) Every person is presumed not to suffer from a mental disorder so as to be exempt from criminal responsibility by virtue of subsection (1) until the contrary is proved on the balance of probabilities.

Burden of proof

(3) The burden of proof that an accused was suffering from a mental disorder so as to be exempt from criminal responsibility is on the party that raises the issue.

Defendants Found Not Guilty By Reason Of Insanity

Contrary to what many people believe, if a person is not convicted by reason of insanity, he/she is not set free right away. Rather, the person is confined to a mental institution. They are to remain there until their sanity is established. Moreover, there is a chance that the defendant will have to spend more time in the mental facility than in prison.

Moreover, it is possible for the defendant to be termed mentally incapable of facing a trial. Defendants cannot be prosecuted if they suffer from a mental disorder that prevents them from understanding the proceedings and assisting in the preparation of their defence.

If the defendant displays unusual behaviour, a judge, prosecutor, or defence attorney may ask that trial be delayed until the defendant has been examined and his/her ability to understand the proceedings is proven.

About Slaferek Law

Slaferek lawyers are highly proficient at strategizing effective defence strategies that can lead to case dismissal, reduced charges, reduced penalties, and more. To get in touch with us today, click here. Our expertise lies in criminal cases and DUI cases.

If you are scrambling with murder charges or are looking for a good criminal defence lawyer to fight your case, our team of trained lawyers can help you build a strong case. We have successfully closed hundreds of cases pertaining to murder, DUI, financial fraud and more.

Preserve Your Rights By
Contacting Darin H. Slaferek

We specialize in criminal law, delivering ethical, effective, and efficient legal solutions that prioritize the best interests of our clients.