Scottish jury research - mock jury study: summary of findings

Methods

The study was the largest of its kind ever undertaken in the UK, involving 64 mock juries and 969 individual participants. The research team staged jury deliberations between May and September 2018, in venues in central Glasgow and Edinburgh. Jurors were recruited to be broadly representative of the Scottish population eligible for jury service in terms of gender, age, education and working status.

In order to assess the effect of the Scottish jury system's unique features on decision-making, juries varied in terms of the number of verdicts available to them (two or three), jury size (12 or 15) and the size of majority they were required to reach (simple majority or unanimity).

Each jury watched a video of a fictional but realistic Scottish trial (either a mock rape trial or a mock assault trial) lasting approximately one hour. Jurors completed a brief questionnaire recording their initial views on the verdict, before deliberating as a group for up to 90 minutes and returning a verdict (if the jury had been able to arrive at one). After returning their verdict, jurors completed a final questionnaire covering their beliefs about the not proven verdict and views about the deliberation process, as well as their final views on the verdict.

Both mock trials were deliberately finely balanced, in order to encourage debate about guilt and acquittal, and to maximise the likelihood that jurors would consider the difference between the not guilty and not proven verdicts.