The research sought to determine what effects certain unique features of the Scottish judicial system may or may not have on the process of jury decision-making. Scottish juries differ from their English and other English-language jurisdiction equivalents in three key aspects. They:
- are made up of 15 jurors, not 12;
- are required to reach a simple majority, not a unanimous verdict (e.g. 8 vs. 7);
- have three verdicts to choose from, including the option of returning a ’not proven’ verdict.
Almost 1000 people took part in the research, with 863 members of the public selected to participate in 64 mock jury exercises in Edinburgh and Glasgow. Each mock juror watched a one-hour fictional trial film, which served as the basis for deliberations in their jury. Prior to and following the 90-minute deliberation, individual jurors were asked to complete questionnaires to capture their views on the deliberation process and their understanding of the ’not proven’ verdict.
The report concluded that each of the unique features of the Scottish system may have an effect on the outcome of finely balanced trials. It found that:
- reducing jury size from 15 to 12, may lead more individual jurors to switching their position to the majority view;
- asking juries to reach a unanimous or near unanimous verdict may lead more jurors to opt for an acquittal;
- removing the ’not proven’ verdict may lead to more jurors returning a guilty verdict in finely-balanced trials.
It also found inconsistent views on the meaning of not proven and how it differed from not guilty.
Fiona Leverick (Professor of Criminal Law and Criminal Justice) said: "In shining a light on the ways in which jurors understand and use the not proven verdict, this study will help inform ongoing debates about this verdict. It also provides insight into areas where jurors may require additional support or guidance to avoid legal misunderstandings."