Skip to main content
Crimes involving mental health or cognitive impairment
Special procedures may apply if the accused suffers from a mental health or cognitive impairment, at the time of the offence and/or the time of the trial.
banner image

From time to time, the courts have to consider whether an accused person is capable of taking part in the legal process and/or can be held responsible for their actions due to a mental health impairment or a cognitive impairment.

A mental health impairment includes a temporary or ongoing disturbance that effects the judgment or behaviour of a person but it must be significant enough to result in a mental health diagnosis by a psychiatrist. A person who behaves in a criminal manner because of sadness, grief or anger is not suffering from a mental health impairment. A mental health impairment does not include a disturbance that is solely caused by the temporary effect of taking drugs or having a substance abuse disorder. Examples of what may constitute mental health impairment include bipolar disorder, clinical depression or a psychotic disorder. 

A cognitive impairment includes ongoing impairment in adaptive functioning and in comprehension, reasoning, judgment, learning or memory. Examples of what may constitute cognitive impairment include, intellectual disability, borderlines intellectual functioning, dementia, acquired brain injury, and autism spectrum disorder.  

The courts deal with people who are suffering from a mental health or cognitive impairment when they commit a crime differently to other criminal matters. There is also a different process when the crime is a serious (‘indictable’) offence and is dealt with in the District or Supreme Court than when it is a less serious (‘summary’) offence which is dealt with in the Local Court.
It can add to the stress victims and other witnesses are already experiencing when the accused is not dealt with in the ordinary way under criminal law. If mental health is an issue which is raised in a matter in which you are involved the different procedures that may occur are outlined below so you know what to expect. (This information is also available in a brochure.) 

Why the Courts treat these matters differently

A person cannot be found guilty of a crime if, as a result of a mental health or cognitive impairment, they did not understand what they were doing or that what they were doing was ‘wrong’ by normal community standards.

Accordingly the law recognises that in those circumstances the accused is not legally responsible for their actions. It should be noted that although the accused may be found to be not criminally responsible, the Court maintains the power to detain the accused for the purpose of protecting the community and treating the accused. 

In certain cases for serious offences tried on indictment, an accused person may raise their fitness to be tried. In these circumstances a Court generally undertakes an inquiry, often requiring expert medical evidence, to find out whether an accused person is capable of understanding the charges against them and whether they are able to properly take part in court proceedings – in short whether they are ‘fit to be tried’. This is part of making sure that everyone who goes on trial gets a fair trial and can fully and properly instruct their lawyers about their plea and what they have been charged with. Depending on how the Court determines ‘fitness’, the case may then be dealt with in a number of different ways. 

For these reasons, the courts take a discrete approach to criminal matters if there are questions about the accused’s mental health or capacity when the offence was committed, or when they are facing court. In NSW, the procedures outlined in the Mental Health and Cognitive Impairment Forensic Provisions Act 2020 will apply.

How this affects you

It is important for victims and witnesses to know that the legal steps, the verdict and the penalties can all be different in these matters than in other criminal matters.

The prosecution process can become very complex and take a long time, sometimes years, to finalise. If you are a victim in a case where these issues arise, the ODPP solicitor will be able to assist you in understanding the processes in your individual case. 

One of the primary differences that affects you directly is that you will not be called to give evidence in a trial if the accused is not fit to be tried. However, if the offence is serious, the judge holds what is called a ‘special hearing’ and you may still be required to give evidence.