The not proven verdict and related reforms: consultation

This consultation seeks views on the three verdict system in Scottish criminal trials and if the not proven verdict were to be abolished, whether any accompanying reforms would be necessary to other aspects of the criminal justice system.

Part 3: Jury Size


In Scotland the jury in criminal trials is made up of 15 people. Although there was no set number of jurors in the early days of jury trials in Scotland, they were nearly always made up of 15 jurors by the close of the sixteenth century.[14] This number of jurors is generally higher than in other jurisdictions where juries of 12 or 9 are far more common.

Previous considerations

The size of the Scottish criminal jury was considered in the 2008 Scottish

Government consultation “The Modern Scottish Jury in Criminal Trials”. At that time, the Government was not proposing reform of the number of jurors but was looking to stimulate debate on the issue to test the case for change on a range of matters including juror numbers, and the number required for a conviction.

Less than half of all the respondents addressed the question of jury size and a slight majority of those were in favour of retaining a jury of 15, pointing out advantages including[15]:

  • it allows for majority verdicts;
  • it is less likely that a trial will collapse due to low numbers of jurors;
  • there is less likely to be juror intimidation;
  • juries of 15 have the confidence of public and the courts;
  • a larger jury is less likely to be imbalanced by individual prejudices; and
  • it is more likely to include a mix of gender, ethnicity, experience and social awareness.

The question of what is the most effective jury size has been the subject of great debate internationally and the focus of some cases before courts in other jurisdictions.[16] In particular, it is has been suggested that a smaller number of jurors would be less representative of the population and may lead to an increased chance of a “hung jury” where they have been unable to reach a verdict.

Amongst those favouring a reduction in jury size, it was argued that 15 jurors makes for an unwieldy discussion, and a smaller size of jury would relieve some of the pressure on the jury pool and bring Scotland in line with other jurisdictions.

After considering responses to the consultation, the Scottish Government decided not to legislate to reduce the size of the jury in Scottish criminal trials.[17]

The above advantages were also amongst those taken into account when considering whether a 12 person jury should be adopted in Scotland in the later 2012 Scottish Government consultation “Reforming Scots Criminal Law and Practice: Additional Safeguards Following the Removal of the Requirement for Corroboration”. It was again concluded that the size of the jury in criminal trials should remain at 15.

Jury size was also considered as part of Lord Bonomy’s Post-Corroboration Safeguards Review which recommended that research should be undertaken to ensure any reforms made to the Scottish jury system, including to the size of the jury, were made on an informed basis.

Jury Research

Prior to the independent jury research commissioned by the Scottish Government, there had been no research that directly assessed the impact of having 15 jurors on a criminal jury.

The key findings in relation to the size of the jury were:

  • Jurors in 15-person juries were less likely to change their minds on the verdict than people in 12-person juries.
  • 15-person juries were associated with somewhat lower levels of juror participation than 12-person juries across a number of measures.
  • Reducing the number of jurors on Scottish juries from 15 to 12 might lead to more jurors participating more fully in the deliberations.
  • Reducing the number of jurors on Scottish juries would be unlikely to have much impact on deliberation length or the range of evidential or legal issues discussed.

Jury Research: engagement sessions

Participants in the subsequent jury research engagement sessions were asked, “based on the research findings and your own experience, do you consider that any reforms are needed to jury size? If so, what and why?” It should be noted that this question sought views on changes to jury size as a standalone reform, rather than in direct consequence of a move to two verdicts.

In comparison to the other aspects of the Scottish jury system discussed, less strong opinions were expressed on the size of the jury. This was common across all the sectors in attendance and most participants were of the opinion that the size of the Scottish jury should remain 15, although did not appear to have particularly strong feelings about this. The main reasons provided largely reflected those set out above.

However there were some participants that felt the jury size should be reduced, highlighting that:

  • 12 jurors works well in other jurisdictions;
  • there are better ways to ensure that juries are representative of the wider population than simply having three extra jurors;
  • it is harder to participate in larger groups, as highlighted in the jury research; and
  • there are additional costs and practical difficulties with 15 jurors.


As set out above, the jury research suggested there may be advantages to reducing jury size in terms of increased participation in deliberations. In addition to this, there would be cost savings due to the resulting reduction in expenses paid to jurors, as well as benefits to society in the form of fewer persons having reduced income while they are taken out of their regular employment to serve on a jury. Businesses would also benefit from greater availability of staff, and less disruption to their work which could be of particular benefit as the economy deals with the difficulties caused by the Covid-19 pandemic.

Despite these benefits, it was clear from the engagement events, and previous considerations of the issue, that stakeholders have less strong views about reforming the size of the Scottish jury (although these discussions largely took place prior to the pandemic and its impact on businesses).

During the engagement there was little appetite for changing the jury size as a standalone reform. This consultation seeks views on whether a change to the number of verdicts available or to the majority required would in turn impact on what the most appropriate jury size would be.


Having considered the views expressed throughout previous considerations of jury size, the evidence from the recent jury research and views gathered at the subsequent engagement sessions, the Scottish Government is seeking views on the following questions.

These questions focus on jury size. There are specific questions on not proven in part 2, on jury majority in part 4, and corroboration in part 5.

Question 8: Which of the following best reflects your view on jury size in Scotland? If Scotland changes to a two verdict system:

  • Jury size should stay at 15 jurors
  • Juries should change to 12 jurors
  • Juries should change to some other size

If you selected “some other size”, please state how many people you think this should be:

Please give reasons for your answer including any other changes you feel would be required, such as to the majority required for conviction or the minimum number of jurors required for the trial to continue:



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