Ministry of Justice data challenges myths about conviction rates in sex case jury trial

Neil Sands

Official figures show that sexual violence cases heard by a judge alone have lower conviction rates than those that go before a jury, challenging long-standing assumptions that juries are vulnerable to “rape myths” and less likely to convict than judges.

The Ministry of Justice data, obtained by The Law Association’s Criminal Law Committee through an Official Information Act (OIA) request, shows that the average conviction rate in judge-alone trials for sexual violence offences from 2016-2025 was 57.2%.

For jury trials, the average rate was 63.9%, with the higher figure for jury trials a consistent pattern over the entire decade, except for 2018, when jury and judge-alone convictions were both 64%.

Criminal Law Committee convenor Julie-Anne Kincade KC said the figures showed the importance of the jury system, amid calls from victim advocates to have sexual violence cases heard by judge alone because juries are unqualified to deal with such a specialist topic.

Julie Anne Kincade KC

“What the figures tell us, on the face of it, is that if anyone were to suggest that there’s somehow more of chance of conviction with a judge-alone trial than a jury trial, it’s just not true,” she said.

“In discussions around sex trials and how to make the process more victim-friendly, there’s an idea that it is somehow easier for a complainant to give evidence in front of a judge rather than a jury and that often it is suggested that juries get it wrong when they acquit a defendant. The suggestion is that if sexual offending cases were heard in front of a judge alone, as opposed to a jury, the conviction rate would be higher.

“That’s because the assumption is that judges will get it right and juries get things wrong. It has no factual basis whatsoever. A judge is one person, and whilst they have a legal qualification, they are as fallible as juries. Juries are 12 people, and that is the strength of a jury, the safety is in the numbers,”

Table 1: Number and percentage of sexual violence cases in New Zealand where a trial was involved, by case track, case outcome, and year, disposed of between 1 January 2016 and 31 December 2025. Source: Ministry of Justice

‘Recipe for injustice’

Victoria University of Wellington law professor Yvette Tinsley outlined her reservations about jury trials for sex cases in a 2023 commentary, saying they were “a recipe for injustice” because jurors “bring stereotype and irrelevancy to the deliberation room.

“It is well-established that there are many myths and misconceptions about sexual offending in our community, from which juries are drawn,” she wrote.

“These misconceptions include expectations that rape is physically violent, that victims should fight back, that ‘real rape’ is perpetrated by ‘a stranger in the bushes’ and that it is reported immediately.”

Kincade said judges were just as likely as jurors to have inherent biases.

“The fundamental basis of having jury trials and the fairness of them is that you are being assessed by people who live in the same world as you do, effectively, and perhaps not in the more limited world that a judge may live in,” she said.

“By virtue of the fact they [judges] are only one person, there’s a greater chance of them living in more of a vacuum than 12 members of the public.”

Kincade cautioned that the Ministry of Justice figures are not conclusive, as it does not detail which cases were contested and which were resolved through guilty pleas. The ministry said it did not have the data to provide such a breakdown.

But she said the figures gave a general indication of conviction trends and pointed to a 2023 British study which found that, contrary to popular opinion, juries were more likely to convict in rape trials (58%) than for offences such as manslaughter (48%), grievous bodily harm (48%) and attempted murder (47%).

The study, which examined 5.6 million charges and 68,863 jury verdicts in England and Wales between 2007 and 2021, cited a petition submitted the Parliament in 2018 erroneously claiming that the conviction rate in jury rape trials was 21% lower than other crimes. The study’s authors concluded: “Jury decision-making in rape and sexual offences cases continues to be an area where much is claimed often with no evidence based on research with real juries.”

Table 2: Highest and lowest jury conviction rates by deliberation in England and Wales (2007-2021). Source: UCL Jury Project.

Spotlight on jury trials

The future of jury trials is under the microscope in New Zealand as the government looks for cost savings in the justice system and ways to cut down a backlog of cases.

Justice Minister Paul Goldsmith recently told a function organised by The Law Association that the proportion of trials where defendants elect to be heard by a jury, rather than judge-alone, has more than doubled in the past decade, contributing to a 64% increase in the number of jury trial cases over the same period.

“They, of course, take much longer and are much more expensive in terms of legal aid,” he said.

Goldsmith referenced moves in Britain to scrap jury trials for all but the most serious cases, The changes there will mean jury trials will still be guaranteed for offences such as rape, murder, aggravated burglary, blackmail, people trafficking, grievous bodily harm and serious drug prosecutions.

But cases attracting a likely sentence of three years or less, as well as complicated fraud/financial cases, would be heard by a judge alone.

In New Zealand, a defendant facing a potential jail term of two years or more can elect to have a jury trial.

Justice Ministry officials have said they are watching developments in Britain closely, while the government here has repeatedly said victims are a priority in justice sector reforms, meaning it may be receptive to advocates’ calls to end jury trials for sex cases.

Fact-based decisions

Kincade said any changes to the right to trial by jury – first formally set out in the Magna Carta of 1215 – needed to be carefully thought through.

She opposed introducing a separate trial system for sex cases and said assumptions that judge-alone trials were cheaper and shorter than jury trials were contestable and needed to be thoroughly scrutinised before change was introduced.

“If we’re going to have a debate on these sweeping changes that are being called for, can it please be based upon factual findings? Can there be some studies? Can there be some analysis?” she said.

“We [the Criminal Law Committee] have scraped the surface here, but it is really for the academics and others, who are putting forward these bold suggestions to undermine our jury system that has been in place for hundreds of years, to provide actual hard facts and analysis, rather than the typical anecdotal stories, which are not borne out when you actually look at them.”

Kincade said research like the British study was needed to provide a clear view of the situation in New Zealand.

“If we change anything about the system here, it will need to be based on facts, rather than suggestions and myths that are often perpetrated without any factual foundation,” she said.