How Does the Defence of Mental Impairment Work in Australian Capital Territory Law?

I was insane, Your Honour! How does the defence of mental impairment work in Australian Capital Territory law?

Mental impairment is one of the most talked about defences that criminal defendants raise in a court of law. Sometimes, the defence of mental impairment and the way it is perceived in “getting someone off” a crime means the defence makes its way into the media. People tend to think “I’ll just say that I was nuts, and that’ll get me off”.

However, the defence of mental impairment is complicated, and just because you are found not guilty by reason of mental impairment, it does not mean the matter ends there.

In this article, we discuss how mental impairment works as a defence, how it works at sentencing if you raise mental impairment, and why the defence is so complicated.

Mental Impairment as a defence to a crime.

Section 28 of the Criminal Code 2002 provides that a person is not criminally responsible for an offence if, when carrying out the conduct required for the offence, the person was suffering from a mental impairment that had the effect that:

1. The person did not know the nature and quality of the conduct; or
2. The person did not know that the conduct was wrong; or
3. The person could not control the conduct.

When considering whether the person knew that the conduct was wrong, Section 28(2) provides that a person does not know that conduct is wrong if the person cannot reason with a moderate degree of sense and composure about whether the conduct, as seen by a reasonable person, is wrong.

When the person raises a defence of mental impairment, they are presumed not to have been suffering from a mental impairment. That presumption of sanity is displaced only if it is proved on the balance of probabilities that the person was suffering from a mental impairment.

So, what is a “mental impairment”?

Section 27 of the Criminal Code 2002 provides that mental impairment includes “senility, intellectual disability, mental illness, brain damage and severe personality disorder”.

Mental illness is defined as an underlying pathological infirmity of the mind, whether of long or short duration and whether permanent or temporary, but does not include a condition (“a reactive condition”) resulting from the reaction of a healthy mind to extraordinary external stimuli. A reactive condition may be evidence of mental illness however if it involves some abnormality and is prone to recur.

All of that being said, it’s not enough of itself to have a mental illness or brain damage. The mental impairment must have the effect that either the person does not know that their conduct was wrong, did not know the nature and quality of their actions, or that they could not control their conduct due to mental impairment.

So, for example, just because you have been diagnosed with PTSD or another mental illness, it does not mean you are not guilty unless that illness impacts on you by rendering you incapable of knowing that your conduct was wrong, knowing the nature and quality of your actions, or means that you cannot control your conduct.

It’s not all roses.

Even if you succeed in establishing that you are not guilty due to mental impairment, that may not be the end of it. If your case is before the ACT Supreme Court, Section 28 provides that the Court must return a special verdict that you are not guilty of mental impairment, which, for example, could result in you spending that amount of time you might have spent imprisoned in a secure mental health unit. You may otherwise be subjected to mental health orders or forensic mental health orders in the ACT Civil and Administrative Tribunal. 

As such, the perception that it’s a “get out of jail free card” is misguided. Sometimes, mental impairment can result in a person being locked away, but in a different way.

How Mental Impairment Can Affect Sentencing

If you don’t raise it at your trial but raise it at your sentence and you have evidence to support it, mental impairment can have an impact on your sentence and potentially reduce it.

Due to the decision of R v Verdins (2007) 16 VR 269, mental impairment can affect sentencing in a few different ways:

• Reduce moral culpability, thus affecting just punishment in regard to denunciation
• Influence the sentence or the conditions in which it could be served
• Reduce the effectivity of a particular sentence, depending on the gravity of the accused’s situation
• Increase hardships of the accused upon being imprisoned due to the mental illness
• Justify the lessening of the gravity of a sentence due to the risk that imprisonment may pose upon the accused

Experienced criminal lawyers may raise these principles at a sentencing hearing, and they are colloquially referred to by lawyers as the Verdins principles.

The Bottom Line

Mental impairment may have a major impact on whether you can be acquitted of a criminal offence or have your sentence reduced due to your mental illness being taken into account. If you have a mental illness, you absolutely should disclose to a criminal lawyer your specific mental disorders, as this may greatly assist you in your case.

Are you looking for a leading criminal lawyer to represent you in Canberra, Queanbeyan, Wollongong, Goulburn and surrounds? Get in touch with Andrew Byrnes Law Group today and have one of our lawyers find the best possible defence for you.