Musings from the Mushroom Murder Trial: Key Takeaways for Workplace Investigators
The renowned 2023 beef wellington mushroom poisoning case has culminated in Erin Patterson being found guilty of 3 murder charges and 1 charge of attempted murder. Although workplace investigators are not required to be satisfied ‘beyond a reasonable doubt’ and need only be satisfied on ‘the balance of probabilities’ to substantiate allegations, the mushroom murder trial offers 6 useful reminders for workplace investigators when conducting investigations.
Don’t underestimate digital forensics
The prosecution’s success in the mushroom murder trial hinged on meticulous digital evidence such as Patterson’s online activity, including visits to death cap mushroom identification sites well before the incident, and her use of a food dehydrator purchased in April 2023.
Takeaway 1:
You don’t know what you don’t know. Thorough examination of digital footprints such as digital communications, browsing history and device metadata can reveal compelling evidence, such as attempts to conceal evidence or insights into the Respondent’s motives or actions.
Pay attention to chain of custody
As in a workplace investigation, the integrity of physical evidence such as toxins in the food dehydrator was paramount in the mushroom murder trial. Any misstep in handling such evidence could have jeopardized the outcome of the case.
Takeaway 2:
Ensure adherence to chain-of-custody protocols in the collection, documentation and handling of physical evidence to preserve its integrity.
Don’t forget about circumstantial evidence
Even if direct evidence is scarce, circumstantial evidence such as evidence which points towards a lack of credibility can paint a compelling picture. In Patterson’s case, inconsistent statements such as falsely claiming the mushrooms were store-bought and fabricating a cancer diagnosis spoke to a lack of credibility.
Takeaway 3:
In the absence of direct evidence, meticulously analyse circumstantial evidence to construct evidence-based findings of fact, including credibility findings.
Consider alternative theories
Throughout the trial Patterson maintained that the poisonings were accidental. However, the jury found otherwise. While remaining impartial and open to alternative theories is essential, so is objectively testing the plausibility and credibility of such theories.
Takeaway 4:
Investigators should remain open to alternative explanations or versions of events to remain impartial and avoid confirmation bias.
Motive matters sometimes (but not always)
The absence of a clear motive did not hinder the prosecution’s success in the mushroom murder trial. While motive can provide context, the focus should remain on the Respondent’s alleged actions and available factual evidence.
Takeaway 5:
While understanding motive can be insightful, especially if there are concerns of a vexatious complaint, conclusions ought to be based on concrete evidence.
Plug knowledge gaps through expert consultation
In the Patterson case, a Fungi specialist and public health officials provided critical insights into the identification of death cap mushrooms and the improbability of accidental contamination of the beef wellington. Similarly, workplace investigators should not shy away from seeking external expert advice to comprehend and test technical aspects of their case.
Takeaway 6:
Know your limitations. Engaging with subject matter experts can provide valuable insights into complex technical aspects of an investigation that you may not be equipped to deal with.
Connect with us
For support with your fworkplace investigations or disciplinary processes, reach out to our team at hello@mapien.com.au and one of our workplace strategists will be in touch within 24 hours.