The Verdins Limbs and Personality Disorders: The implications of New Precedents in Criminal Law

The Verdins limbs provide important considerations for sentencing in criminal law matters when the defendant has impaired mental functioning at the time of committing the index offence and/or at the time of sentencing. The Verdins limbs include consideration of how the defendant’s mental health problems may be relevant to the sentencing process with respect to: moral culpability, the nature of the sentence and the conditions in which it should be served, general and specific deterrence, and the impact of imprisonment on mental health.

The Verdins limbs have provided scope for a broader range of mental health difficulties to be considered in sentencing, as prior to Verdins (2007), sentencing considerations were more restricted to defendants with diagnosed chronic and severe mental illness. The Verdins limbs have provided an avenue for consideration of the impact of acute mental health difficulties at the time of the offending and/or sentencing. This development has been important for the identification of mental health treatment and rehabilitation targets that may reduce the risk of recidivism, and provide a better outcome from a community safety perspective.

Until recently, the widely quoted case precedent of DPP (Vic) v O’Neill (2015) held that personality disorders do not constitute an impairment of mental functioning, and therefore should not mitigate an offender’s sentence or be considered in the context of the Verdins limbs. However, new case precedents have overturned this position (e.g., Brown v R 2020), and the Verdins limbs have been successfully applied in criminal law cases in Australia when the defendant has been diagnosed with a personality disorder. The new precedents have significant implications, given the diversity of criminal behaviour that is engaged in by personality disordered offenders, and the higher rates of personality disorder in prison populations when compared to the wider community.

The new case precedents in relation to the Verdins limbs and the inclusion of personality disorders do not automatically qualify all offenders with personality disorders to sentencing mitigation in accordance with the Verdins limbs. However, the precedents do invite the consideration of the chronic emotional and behavioural disturbances inherent to personality disorders in sentencing. By clinical definition, personality disorders manifest in patterns of cognition, emotional experience, emotional expression, and behaviour that are maladaptive and manifest across a range of personal and social situations. With respect to offending behaviour, these manifestations can present in many ways, including through interpersonal violence, stalking, property damage, and fire-setting.

Psycho-legal assessments can investigate what the evidence shows about the nature, extent and effect of any mental impairment experienced by the defendant at the relevant time, and apply that knowledge to the application of the Verdins limbs. The relevance of expert evidence in such cases is highlighted by the new precedent of Brown v R (2020) which includes the following:

“An offender diagnosed with a personality disorder should be treated as in no different position from any other offender who seeks to rely on an impairment of mental functioning as mitigating sentence in one or other of the ways identified in Verdins. Statements to the contrary in O’Neill should no longer be followed. Whether and to what extent the offender’s mental functioning is (or was) relevantly impaired should be determined on the basis of expert evidence rigorously scrutinised by the sentencing court.”

The psycho-legal assessment of the nature, extent and effect of personality disorder experienced by the defendant at the relevant time requires consideration of the severity of the personality disorder (as such disorders are defined on a severity continuum), whether a causal link exists between the personality disorder and the offending behaviour, cogent evidence of the established personality disorder diagnosis and longitudinal patterns of behaviour, and consideration of community protection (e.g., prospective treatment responsivity and risk reduction issues).

It is helpful for experts providing psycho-legal assessments of this nature to be briefed by the instructing legal counsel with collateral information such as: the defendant’s criminal record, mental health records (e.g., hospital discharge summaries; treatment provider reports), audio-visual copies of Police interviews with the defendant, Police body-camera footage of the defendant at the time of the index offence, prison health records from prior incarcerations, and any other service provider letters or reports from the community. The expert’s evidence is strengthened by the extent of longitudinal information available to them at the time of the assessment, and the more collateral sources of information, the more informed the resulting assessment will be.

The consideration of personality disorders in this context in criminal law raises numerous philosophical issues, such as the responsibility of individuals with personality disorders to seek and comply with treatment for their condition, as part of their community obligation to take care not to harm others. If it is the case that an offender has not complied with their responsibility to seek and comply with treatment, they may be held fully culpable for their offending behaviour despite their impaired mental functioning. However, the responsibilities extend beyond the individual diagnosed with the personality disorder to health and justice systems that provide treatment and intervention services for individuals with personality disorder. This is an inherently problematic area, as there is a scarcity of resources in Tasmania to fulfil this responsibility. Expert evidence can investigate whether the defendant has had the opportunity to engage with appropriate treatment and has not complied, or whether treatment/intervention services have not been available to them due to lack of resources and expertise.

It is also important to note that although some types of personality disorders are amenable to evidence-based treatments (e.g., Borderline Personality Disorder), there are other personality disorders that do not yet have a strong evidence base for successful treatment.

Finally, it is important to consider that Anti-Social Personality Disorder, and more rarely but relevantly Psychopathic Personality, are diagnoses frequently seen in offender populations due to the very nature of these personality types. By definition, Anti-Social Personality Disorder is characterised by a pervasive pattern of disregard for and violation of the rights of others, including failure to conform to social norms with respect to lawful behaviours, deceitfulness, impulsivity, irritability and aggressiveness, reckless disregard for the safety of self or others, irresponsibility and lack of remorse. Psychopathic personality is more complex and extreme in nature, but can also be characterised by persistent anti-social behaviour, impaired empathy and remorse, interpersonal manipulation, impulsivity, and behavioural disinhibition. To date, the evidence-based literature regarding the treatability of these conditions is not convincing. Internationally, the primary intervention for individuals with these personality disturbances is incarceration in response to offending behaviour, and in extreme cases preventative detention.

It is more likely that personality disorders such as Borderline, Histrionic, and Paranoid will feature in expert evidence regarding the impact of personality disorders that may enliven the Verdins limbs, however it will be interesting to see how the new case precedents operationalise in this area of criminal law.

Dr Georgina O’Donnell
Forensic and Clinical
Psychologist

Dr Georgina O’Donnell is an independent Forensic & Clinical Psychologist based in Hobart. She specialises in psycho-legal assessments across jurisdictions, and provides independent assessments for criminal law, family law, child safety, and psychological injury matters state-wide.