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Scientific evolution: the key lesson from Ellis

30 Jun 2023

| Author: Reweti Kohere

Despite 30 years of scientific development, the reliability of children’s memories as evidence remains an issue that New Zealand’s courts must grapple with as debate within the scientific community persists, a key member of Peter Ellis’ appeal team says.

Contrary to concerns that children couldn’t testify accurately or reliably, the science has shown they could “under the right circumstances”, said Dr Bridget Irvine, who appeared as junior counsel for Ellis in the Supreme Court. Speaking at ADLS’ recent CPD event Examining Ellis: Legal Principles, Developments, and Learnings, Irvine shared some of the lessons to emerge from one of New Zealand’s most defining miscarriages of justice.

In 1993, Ellis was convicted of sexual offences against children while working at a Christchurch crèche. Never wavering in maintaining his innocence, Ellis died in September 2019, more than three years before the Supreme Court would unanimously quash his convictions on the basis of a miscarriage of justice resulting from the expert evidence given at trial.

The case has captivated New Zealanders for the past three decades, and more recently stirred debate among the public and legal profession after the Supreme Court looked to tikanga to help resolve whether Ellis could continue his appeal despite his death.

At ADLS’ CPD event, chaired by District Court Judge Sanjay Patel, the place of tikanga in the law of New Zealand was examined by Bankside Chambers barrister Kingi Snelgar (Ngāpuhi, Ngāti Whakaue, Te Whakatōhea and Ngāi Tahu), who led the appeal’s tikanga submissions alongside Kāhui Legal partner Natalie Coates (Ngāti Awa, Ngāti Hine, Ngāti Tūwharetoa, Tūhourangi, Tūhoe and Te Whānau a Apanui).

The procedural history of the case, and the context in which it arose, was discussed by barrister Rob Harrison, who represented Ellis at his original trial. Another of Ellis’ defence counsel, Augusta Chambers barrister Susan Gray, explored the role s 23G of the Evidence Act 1908 played in the way evidence from experts, who had experience dealing with sexually abused children, was admitted.

Also explored: the evolution of science. “We all think we understand memory because we have one. Juries think they understand memory because they have one,” said Irvine, a senior associate in the dispute resolution and litigation team at Christchurch firm Taylor Shaw.

“It’s a real problem for our system generally, and so we were really lucky that our experts were so generous with helping us understand memory and the nuances of it – and ultimately helping the court.”


Changing science

Irvine started her career as an academic at the University of Otago, where she completed her PhD in forensic psychology. Her doctoral studies focused on the way in which children are cross examined in the courtroom.

While at Otago, she got involved with Ellis’ case as the co-ordinator of the Innocence Project New Zealand, which offers pro bono legal assistance to individuals who maintain they are factually innocent.

The volunteer group, made up mostly of psychology and law students, looked at miscarriages of justice through a psychological lens. Key personnel included former Otago Law School faculty dean Professor Mark Henaghan and former vice-chancellor and psychology researcher Professor Harlene Hayne, who acted as one of the appeal team’s expert witnesses.

Irvine said a large proportion internationally of cases of wrongful conviction rely on the science having changed for their appeals to succeed. “In our view, this is true with Peter’s case.” The key evidence that arguably led to Ellis’ conviction was the children’s accounts of the alleged abuse, she said. Their evidential interviews were played at trial in lieu of direct examination, but the complainants were cross-examined.



In 1993, the science underlying children’s memories was still in its infancy, Irvine explained. Studies were only just starting to emerge, but crucially they were still preliminary; the scientific community wasn’t willing to conclude that children’s memories were as vulnerable to questioning, media reports and other types of suggestive information, as some results were suggesting.

Since then, an “absolute explosion” of research has not only solidified those early findings but expanded the field into other areas, such as how children’s memories work in a forensic context. The starting point has been that “under the right conditions, children can give very reliable accounts”, Irvine said.

The right conditions helped protect the integrity of the evidence, similar to the chain of custody that crime scene materials, such as a gun or a bloody footprint, should go through. “When you find it, you protect it, you bag it, the whole way through until it arrives at trial to make sure it’s not tainted, [that] nothing has interfered with that piece of evidence,” Irvine said. “It’s the same for a child’s memory.”



Ensuring the memory’s purity wasn’t easy, though. While some likened memory to a tape recorder – “you see something, you record it, you store it and then you later play it back” – others, such as Loftus, have likened memory to a Wikipedia page, Irvine said. “You can go on, edit it, other people can come and edit it and what it looks like at the end is very different to the original source of that piece of information.”

Factually incorrect accounts given by others can also contaminate one’s memory of an event. An eyewitness could have observed a white car speeding away from a bank robbery, only to tell the police the car was actually green after having heard a media report that described a green getaway car, the senior associate explained. “You’ve taken in that information from the media reports and it’s changed your memory – even though you initially saw that white car.”

The distortion this “misinformation effect” could create is varied. After canvassing thousands of pages of scientific methods about memory, the appellant’s team distilled the following key principles: first, misinformation permanently alters memory. Consequently, it can’t be unwound and it could lead to one constructing an entirely false report.

Second, memory weakens if the retrieval of an event is delayed. In Ellis’ case, from when one of the complainants last interacted with him (based on the most conservative measure of memory) until they gave their evidential interview, the longest delay was about 1,400 days, Irvine said. “It’s a pretty long time in anyone’s life, as an adult, but when you’re a child, that’s an immensely long period of time.”

Third, richly detailed and consistently maintained false reports can seem “extremely credible”. One of the arguments run in 1993 was that false accounts would lack detail. “But the science has now shown us these memories can be as true as something that you’ve experienced.” And fourth, there is no scientific method for an interviewer, a child, or a fact finder to distinguish between true and false memories.


Falling away?

One of the key lessons from the case was the close co-operation between the lawyers and the experts. The defence team managed to pull in “the best of the best” on memory. The calibre of the experts, to which the Supreme Court had access, would be important for future cases to consider when relying on memory as evidence, Irvine said.

“Children and humans with memories continue to appear in our courts and it’s important we understand the frailties with it.” The reliability of children’s memories had been at issue before every court that heard Ellis’ case, Irvine said. In 1999, the Court of Appeal concluded it shouldn’t be asked to make determinations about issues the scientific community had not yet resolved. Nor should it be asked to evaluate the impact of factors on the reliability of children’s testimony when they couldn’t be measured at the time.

“That was our starting point,” she said, “and our argument was that those concerns had fallen away.” By achieving agreement among most of the world’s authorities on memory that there was consensus on the factors that could compromise the accuracy of children’s memory reports, the defence had tried to alleviate any potential judicial concerns. Moreover, Hayne’s empirical methods had demonstrated the complainants in Ellis’ case were exposed to several pre-interview factors that had subsequently been shown as contaminants. “We were saying the expert evidence that was led by psychiatrists – they weren’t memory experts themselves – substantially understated the level of risk.”



Irvine said the team had hoped for a hefty statement from the court on reliability. While it was prepared to conclude several contamination factors were canvassed at the trial, the court concluded the reliability debate still existed among memory experts “even today”. The court had asked the parties’ experts to produce a statement of principles which could be provided to juries. The experts couldn’t agree though and produced markedly different statements.

It was an “upsetting” position, Irvine said, given the defence team had argued strongly about how the courts could proceed in understanding memory. However, the court was persuaded to accept the jury in Ellis’ case was misled by psychiatrist Dr Karen Zelas, the Crown’s expert, who incorrectly rejected or minimised the risk of contamination, among other things. Evidence from another expert didn’t suffice to neutralise Zelas’ impact.

The issue of children’s memory would undoubtedly appear before the Supreme Court again, Irvine said. “I just hope we can get all the right experts back in that room – to have a similar argument.” ■


Missed ADLS’ ‘Examining Ellis’ seminar? Purchase the On Demand course now.

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