Patterson’s sentence answers one question. But the two most important remain unanswered

1 week ago 3

Opinion

September 8, 2025 — 3.51pm

The trial that has consumed the public since 2023 came to a kind of close on Monday, with Erin Patterson sentenced to life in prison with a non-parole period of 33 years. And yet, two of the biggest questions remains unanswered: what was Patterson’s state of mind at the time of offending, and what motivated her to feed four of her relatives a meal laced with death cap mushrooms?

The prosecution provided no motive for the murders and were not required to. They simply needed to prove that her acts were intentional and designed to cause death. The defence’s case was similarly unilluminating, likely built around her instructions that the mushrooms were mistakenly placed in the meal.

Erin Patterson leaves court after being sentenced to life in prison on Monday.

In the absence of any clear motive or information about her mental state and functioning, and even before sentencing, many armchair detectives and faux psychologists have been quick to theorise about the diagnosis that may have driven Patterson’s actions.

When I tuned into Justice Christopher Beale’s verdict on Monday morning, I was especially surprised that no pre-sentence reports that might have been completed on Patterson were submitted. These reports are usually ordered by the court or the defence, and are normally completed by forensic psychiatrists or psychologists to shed light on the accused’s mental state at the time of offending.

They can offer reasons for the crime and any mitigating factors (including diagnoses) that should be considered in sentencing, such as details about prognosis, any intervention or treatment that might be needed, and a risk assessment. These assessments often offer the clearest insight into an offender’s inner world.

The most likely reason for no evaluation in this case is that Patterson herself preferred not to engage in the process, though there is a small possibility that the court chose not to request an evaluation. Her unwillingness to talk about her offences means that we will now remain unclear about her motives, including the contribution of any mental disorder.

When someone kills other people in a shocking manner, we commonly turn to a person’s mental state and functioning for explanation. While we’ve moved some way from claiming that those with mental illnesses are inherently dangerous, we often default to this spurious explanation when dissecting crime.

By seeing violence as a direct result of a personality flaw or some other form of in-built mental disorder, we can explain and categorise it in a way that allows us to preserve a sense of separation between the violent person and the rest of humanity, and maintain protective ideas of the world being safe and people being inherently good, bar a few bad eggs.

Offences usually occur when a constellation of factors come together. Mental illness or personality disorders can be a contributing factor, but they are rarely the sole reason someone offends. Exploring these issues requires nuance, sensitivity and a recognition that most people with a specific disorder – even the much-maligned narcissistic personality disorder – will not offend violently. Typically, piecing together an offence involves understanding an offence map and the tiny, seemingly unimportant factors that coalesce to create violence against the backdrop of a person’s psychological makeup.

Patterson has consistently maintained her innocence and claims that the deaths were a tragic accident, even as her fluctuating stories and meticulous preparation belie her hypothesis. Denial, though, is common for certain forms of offending (sex offending is a prime example of a crime that is often denied). This is sometimes because of deep-seated shame, and sometimes personality factors. Entitlement, for example, could contribute to offending, and make it more likely that an offender will be unable or unwilling to acknowledge the reality of their behaviours.

Those who deny offences often tend to be externalising, aggrieved by their involvement in the justice system, and often perceive themselves as the real victim. While most people, including those within the courts, believe denial means someone poses a higher risk of re-offending, research consistently shows that denial and remorse have little relationship to recidivism. However, we rely on this as a shortcut to assess a person’s morality.

As a forensic psychologist, I am not overly invested in shifting denial. But I do find it problematic when trying to understand an offence. Without a frank conversation about an offence, determining a relevant treatment or management target becomes more difficult, and this may influence risk.

All this is moot for Erin Patterson. At the very least, she will spend the next three decades in prison, and will be in her 80s before she is eligible to even apply for parole. While her mental state at the time of the offending remains opaque, her every move will now be surveilled and recorded, with very close supervision if she is ever released into the community.

Dr Ahona Guha is a clinical and forensic psychologist, trauma expert and author based in Melbourne.

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