Scottish jury research: findings from a mock jury study

Key terms

Some of the key terms used in this report are set out here.

• Accused. A person charged with committing a crime or offence.
• Beyond reasonable doubt. The standard of proof in a criminal case (see also 'standard of proof' below). See section 4.3.1 for the standard judicial directions on reasonable doubt.
• Complainer. A person who, in criminal proceedings, claims to have been the victim of an offence.
• Consent. In Scottish criminal law, consent in a sexual offence case means that the complainer freely agreed to have a particular type of sexual contact with the accused. Most sexual offences require proof that the accused acted without the complainer's consent.
• Corroboration. The requirement in a Scottish criminal case that, to find the accused guilty of a charge, there must be two separate sources of evidence that (a) the crime charged was committed, and (b) the accused was responsible for committing it.
• Deliberations. The process of discussion by which juries reach a verdict. In this research, mock juries were able to deliberate for up to 90 minutes.
• Directions/jury directions/judge's directions. The instructions given by a judge to a jury at the end of a criminal trial that tell the jury the legal tests that they should apply.
• Dominant juror. A juror who contributes substantially more than most others in a particular jury.
• Hung juries. Where a jury is required to reach a certain majority (e.g. 10 votes out of 12) in order to return a verdict, and cannot do so, it is referred to as a 'hung jury'. Hung juries are a feature of many jury systems, but Scottish juries cannot 'hang' as they have 15 members and return verdicts by a simple majority of votes.^[1] This research included mock juries that returned simple majority verdicts, and so could not hang.^[2] It also included mock juries that were required to reach at least near unanimity (10 of 12 members, or 13 of 15 members), which could hang if the minimum number of jurors required for a verdict was not reached.
• Jury-level and juror-level. This study examines both the verdicts reached by each mock jury following deliberation (jury-level data) and the views of individual participants (juror-level data). For a full discussion of this distinction and its relevance, see section 3.2.
• Jury size. The number of people sitting on a given jury. Half of the mock juries in this study had 15 members (the current Scottish practice); the other half had 12 members.
• Majority required. The number of jurors required to support a verdict before it can be returned. Half of the mock juries in this study could return a verdict if a simple majority of jury members (eight of 15 members, or seven of 12 members) were in favour of it. This is referred to in this report as a 'simple majority' verdict. The other half were asked to try and reach unanimity (that is, all members agreeing). If they could not do this then they were permitted to return a 'near unanimity' verdict with no more than two jurors dissenting (that is, they required 10 votes from 12 or 13 votes from 15 to return a verdict).
• Minimally contributing juror. A juror who says very little during deliberations. In this research, a juror was described as 'minimally contributing' if they made fewer than three contributions, excluding non-verbal contributions (e.g. nodding), simple agreement (e.g. 'yes, I agree' with no expansion), or very short contributions made only as part of a 'going around the table' to check which verdict each juror supported.
• Mock jury. The juries in this study comprised members of the public who were eligible to serve on a jury, but were asked to come to a verdict based on a (fictional) filmed trial simulation, rather than a real criminal case. This is a well-established type of research which is normally referred to as 'mock jury research'.
• Not proven. Not proven is one of two acquittal verdicts available in Scotland (the other being not guilty). It has the same effect in law as not guilty.
• Number of verdicts. Half of the mock juries in this study had a choice of three verdicts: guilty, not guilty, and not proven. The other half had a choice of two verdicts: guilty and not guilty.
• Pre-deliberation and post-deliberation. Mock jurors in this study completed two questionnaires. The first, the pre-deliberation questionnaire, was completed immediately after they had watched the trial simulation but before deliberating with the other members of their jury. The second, the post-deliberation questionnaire, was completed after deliberations had concluded. The terms pre-deliberation and post-deliberation are used to refer to these two different stages.
• Self-defence. A legal defence to a crime of violence where the accused claims that they only used force against a person in order to prevent that person from attacking them. See section 4.3 for the legal test that applies to this defence.
• Simple majority. A rule requiring a majority of jurors (eight out of 15 or seven out of 12) to support a verdict before it can be returned. This is the rule that currently applies in Scotland.
• Standard of proof. The level of certainty needed to prove a legal claim. In a criminal trial this is "beyond reasonable doubt". That is, the accused should only be convicted if jurors are satisfied beyond reasonable doubt of their guilt.
• Trial simulation. A realistic, but fictional, portrayal of a trial. This research included two filmed trial simulations (or 'mock trials') - a rape trial and an assault trial. These were performed by actors (with the exception of a retired judge, who performed that 'role'), using scripts developed by the research team with advice from senior Scottish legal professionals.
• Unanimity and 'near unanimity'. A rule requiring that either all, or almost all, jurors support a verdict before it is returned. Unanimity implies that every juror supports the verdict, while 'near unanimity' requires no more than two dissenting jurors (i.e. 10 out of 12 or 13 out of 15 must agree). In systems operating this rule, juries are usually asked to reach unanimity initially. However, if they are unable to do so, they are instructed that a 'near unanimous' verdict may be accepted. This is the rule that currently applies in England and Wales.
• Verdict choice. This report uses the term 'verdict choice' to refer either to the verdict chosen by the jury (i.e. the verdict actually returned), or to the verdict which individual jurors personally preferred (as indicated in their responses to questionnaires administered before and after deliberations), which may differ from the verdict returned by the jury as a whole. The report makes it clear in each case whether jury-level or juror-level verdict choice is being considered.