Victoria Legal Aid

Explainer – The Crimes Mental Impairment and Unfitness to be Tried Act

A plain-language explainer about the Crimes Mental Impairment and Unfitness to be Tried Act 1997.

Monday 30 November 2020 12:00am

What is the Crimes Mental Impairment and Unfitness to be Tried Act 1997 (CMIA)?

The CMIA is based on two fundamental legal principles:

  1. everybody is entitled to a fair trial
  2. people should only be punished for behaviour for which they are 'criminally responsible'.

Applying these two principles sometimes means that people who suffer from serious mental health conditions or cognitive impairments and commit crimes need to be treated differently from other offenders.

A fair trial

If a person who is charged with an offence is found by a court to be ‘mentally impaired’, they may not be able to understand many things about their criminal trial, including:

  • why they are in court
  • the meaning of pleading 'guilty' or 'not guilty'
  • how to give evidence to the court and follow other courtroom procedures.

In such cases, the CMIA can be used to say a person is 'unfit to stand trial'. That person will then go to a 'special hearing', which is similar to a criminal trial, but designed for people with serious mental health issues or cognitive impairment. At the end of the special hearing, a 'supervision order' may be made against the person, meaning that the person receives mandatory psychiatric treatment and also may be detained for a long period of time.

Criminal responsibility and the defence of mental impairment

The law recognises that not everyone is responsible for their actions in the same way. For example, children under 10 years of age cannot be charged with a criminal offence in Victoria, as the law recognises that they do not have the full ability to tell right from wrong. Similarly, the CMIA recognises that in some cases a person with a mental health condition or cognitive impairment will not have the capacity to be criminally responsible for their actions—for example, when the person didn’t know what they were doing, or didn’t know that their actions were wrong. This is called the 'defence of mental impairment'. It is important to note that this defence does not include situations where a person is impaired due to drug or alcohol use. If a person is successful with the defence of mental impairment, the court can make a 'supervision order'. Again, this means that the person receives mandatory psychiatric treatment.

Why do we need the CMIA? Why can’t we put offenders with serious mental health issues in prison?

Ordinarily, if someone is found guilty of a crime, they are punished by a court, sometimes by imprisonment. The reasons for doing this include directly punishing the offender for what they did, protecting society from future harm, and deterring others from committing similar offences.

However, it is not useful to punish people who are not criminally responsible for their actions by putting them in prison. If a person didn’t understand what they were doing at the time they committed an offence, or didn’t understand that the offence was wrong, it is unlikely that they will understand the reason they are being put in prison. It is also unlikely that putting them in prison will make them behave differently in future.

Furthermore, if a mentally ill offender is simply put in prison, their mental illness may go untreated and may still be present when the person is released. This does not protect the community from future harm.

Instead, as an alternative to prison the CMIA ensures the community is kept safer by treating people’s underlying conditions and supervising them closely. This may include mandatory detention in a psychiatric hospital. The focus is not on punishment, but on rehabilitation.

What happens when a supervision order is made?

If a court makes a supervision order using the CMIA, the person becomes subject to long term treatment for their issues and is supervised closely so that their risk to the community is minimised.

Supervision orders can be custodial supervision orders, where the person is detained in a forensic psychiatric hospital, or non-custodial supervision orders, where the person is supported and supervised while living in the community. Failure to obey the conditions of a non-custodial order can mean that the person is placed in custody or in a psychiatric hospital.

A court will decide on what type of supervision order to make by considering the nature of the person’s mental health issues, the type of crime they committed, whether they are a danger to themselves or others, and any statements made by victims.

All supervision orders are made for an indefinite amount of time. When an order is made, a major review date is set. This means that the person’s supervision and treatment must continue at least until that date. For example, for murder, there must be at least 25 years of supervision before the major review. At the major review, the person’s treatment, progress, prospects of rehabilitation, and level of supervision is reviewed by a court. If the person has responded well to treatment, the court may change the conditions of supervision, which can include releasing them back into the community. This rewards good progress and encourages rehabilitation.

Only a court can make decisions to change a person’s level of supervision or allow a person to return to the community. Before these decisions are made, any victims of the offence are notified and can provide a statement to the court.

How often is the CMIA used?

Very rarely. For example, a 2012 review found that the defence of mental impairment is only raised in 1 per cent of the criminal cases coming before the Supreme and County Courts in Victoria. Only a very small proportion of offenders will meet the legal tests necessary to use the CMIA. A person whose offending was caused by drugs or alcohol rather than mental illness will not meet those tests.

Does the CMIA work?

A 2020 study from on reoffending outcomes for people managed under the CMIA found:

  • Since the scheme began no person subject to an order under the CMIA has been charged with a serious violent offence following revocation of their order.
  • The reoffending rate is low: just 21% of people were charged with an offence after being granted either supervised release or absolute discharge into the community (as compared to 50% reoffending rate for mainstream prisoners)

Are people with mental health issues more likely to commit violent offences?

Contrary to many media stories, people with serious mental health issues are more likely to be the victims of crime rather than the perpetrators. But while most people with mental health issues are not violent, a small subgroup of people do commit serious crimes, usually when they have not been adequately treated or supervised. The CMIA therefore recognises that there should be a pathway to address the causes of such people’s offending, with the goals of treatment, rehabilitation, and community safety.

Is using the CMIA ‘getting off’ lightly?

No. The conditions attached to the CMIA are severe. Victoria Legal Aid regularly sees many people spend longer in a forensic psychiatric hospital than they would spend for the same offence in prison. While some are rehabilitated, some people may never become well enough to be released into the community. If people remain a risk to themselves or the broader community, they may remain in treatment and custody for their whole lives.

More information

Find out more about Mental health and your rights.

Reviewed 16 January 2023