Fitness to Stand Trial in WA: The 2023 Mental Impairment Act Explained
Navigating the New Forensic Landscape: Fitness to Stand Trial Under WA's 2023 Mental Impairment Act
Western Australia's forensic mental health framework underwent its most significant transformation in nearly three decades when the Criminal Law (Mental Impairment) Act 2023 commenced on 1 September 2024. For legal practitioners, insurers, and forensic psychologists working with psychological reports for court, this shift carries real and immediate implications.
At Cygnet Medico-Legal Psychologists, we work directly within this legislative environment — preparing medico-legal psychological reports that meet current WA standards for fitness to stand trial, mental impairment defences, pre-sentencing, and a range of civil matters including personal injuries psychological reports Perth and criminal injuries compensation reports WA. This post explains what has changed, why it matters, and how a properly conducted psychological assessment fits into the new framework.
What the 2023 Act Changes — and Why It Matters
The Criminal Law (Mental Impairment) Act 2023 replaces the widely criticised Criminal Law (Mentally Impaired Accused) Act 1996. The old legislation drew sustained criticism for its reliance on indefinite detention, limited pathways for community reintegration, and inadequate oversight mechanisms. The 2023 Act addresses these concerns directly.
Key Reforms Under the New Legislation
- Special criminal proceedings: The Act introduces a clearer procedural framework for matters where an accused may be unfit to stand trial or raises a mental impairment defence, providing more structured court processes than its predecessor.
- Mental Impairment Review Tribunal: Decision-making authority for managing individuals found unfit to stand trial is now consolidated under this Tribunal, replacing the previous ad hoc judicial oversight model and providing more consistent, reviewable outcomes.
- Supervision and management pathways: Rather than defaulting to indefinite detention, the Act establishes tiered supervision orders and community-based management options, reflecting a rehabilitative rather than purely custodial philosophy.
- Safe community reintegration: Explicit legislative pathways now exist for transitioning supervised persons back into the community, with structured criteria and Tribunal oversight at each stage.
These are not merely procedural refinements. They represent a philosophical realignment — one that brings Western Australia closer to the frameworks operating in Victoria and New South Wales, and one that demands high-quality, legally compliant psychological assessments at every stage.
The Role of Psychological Assessment in Fitness Determinations
Under both the old and new frameworks, a court cannot make a finding of unfitness to stand trial without expert evidence. In practice, this means a psychological report for court — or more commonly, a joint psychiatric and psychological assessment — forms the evidentiary backbone of any fitness determination.
A fitness to stand trial assessment in Western Australia typically examines whether the accused can:
- Understand the nature of the charges against them
- Understand the court process and the roles of key participants
- Instruct their legal representative
- Follow and comprehend evidence presented during proceedings
- Enter a plea with understanding of its consequences
These criteria draw on the common law standard established in R v Presser [1958] VR 45, which remains the operative benchmark across Australian jurisdictions despite legislative variation.
Under the 2023 Act, the findings of a psychological or psychiatric assessment may directly inform whether special criminal proceedings are initiated, what supervision conditions are imposed, and when and how a Tribunal reviews a supervised person's status. The stakes of a poorly conducted or non-compliant assessment are therefore significant — both for the individual and for the integrity of the proceedings.
What a Compliant Medico-Legal Report Requires
For legal practitioners instructing experts in Western Australia, it is worth understanding what distinguishes a forensic-grade psychological assessment from a general clinical report.
A medico-legal psychological report prepared for fitness to stand trial purposes should:
- Be authored by an AHPRA-registered psychologist with forensic endorsement or demonstrated forensic competency
- Reference the operative legislative framework — now the Criminal Law (Mental Impairment) Act 2023
- Apply validated psychometric instruments where relevant (e.g., the Fitness Interview Test — Revised, cognitive screening tools)
- Address the Presser criteria explicitly
- Maintain objectivity consistent with the expert witness duties articulated in the Code of Conduct for Expert Witnesses (Federal Court) and equivalent WA standards
- Be structured to withstand cross-examination
Reports that do not meet these standards risk being challenged or excluded — an outcome that serves no one well, least of all a client whose fitness to participate in proceedings is genuinely in question.
The Broader Legislative Context: What's Coming in 2026
Legal and clinical practitioners should also be aware that legislative reform in WA is ongoing. The Mental Health Commission is currently drafting the Mental Health Amendment Bill 2026, expected to be introduced in the second half of 2026. This Bill follows a statutory review of the Mental Health Act 2014 and is anticipated to further refine how mental illness intersects with civil and criminal law in the state.
While the full scope of the 2026 amendments is not yet public, practitioners preparing long-running matters — particularly those involving personal injuries psychological reports Perth, criminal injuries compensation reports WA, or extended supervision orders — should factor potential legislative change into their planning.
Beyond Fitness to Stand Trial: Our Full Scope of Services
Fitness assessments represent one end of the forensic psychology spectrum. At Cygnet, we also regularly prepare:
- Criminal Injuries Compensation (CIC) reports for victims pursuing compensation through the WA scheme
- Pre-sentencing psychological reports addressing risk, rehabilitation prospects, and mitigating factors
- Personal injuries psychological reports for motor vehicle accident and workplace injury claims
- Workers compensation psychological assessments for insurers and legal representatives across Western Australia
- Expert witness reports and testimony for both civil and criminal proceedings
Standard reports are typically completed within two to three weeks of assessment. Priority turnaround options are available for urgent legal matters.
Instructing a Forensic Psychologist Under the New Framework
If you are a solicitor, barrister, or insurer with a matter that may involve fitness to stand trial, mental impairment, or psychological injury, early instruction of a qualified forensic psychologist is strongly advisable. The 2023 Act's structured proceedings mean that expert evidence is required at multiple stages — not just at the point of initial determination.
For individuals who have experienced trauma or psychological injury in the context of a criminal matter, a CIC assessment can also support a compensation claim under the Criminal Injuries Compensation Act 2003 (WA).
Speak With Our Team
Cygnet Medico-Legal Psychologists are AHPRA-registered forensic psychologists based in Perth, Western Australia, with extensive experience preparing court-compliant psychological reports across criminal, civil, and compensation matters. We work with legal practitioners, insurers, government agencies, and directly with individuals throughout Western Australia.
To discuss a referral or request information about our services:
- Fremantle: (08) 9467 6373
- Midland: (08) 9467 7676
We are available to discuss the scope of an assessment, turnaround timelines, and how our reports are structured to meet the requirements of the Criminal Law (Mental Impairment) Act 2023 and other operative WA legislation.