Opinion: James Chalmers

The Scottish Government’s announcement that it intends to abolish the not proven verdict means that it is time that a debate which has focused too heavily on a rearguard action defending Scotland’s third verdict should now consider what other changes might be required to the Scottish jury system.

It is widely thought that abolishing not proven requires a reconsideration of the Scottish practice of allowing verdicts by a simple majority. From a comparative perspective, simple majority verdicts are highly unusual. English-speaking countries generally start from the position that a jury decision should be unanimous, whether for conviction or acquittal. Some systems remain there – Canada, and also the United States, where the Supreme Court decided in 2020 (reversing prior authority) that the constitution requires that verdicts be returned by unanimity. Others have moved away from unanimity by permitting verdicts by majorities of 10:2 or 11:1.

Such jurisdictions have not contemplated more radical change, considering unanimity to be a key feature of the jury, flowing from the requirement of proof beyond reasonable doubt. The concern is often raised that a change in Scotland might introduce the concept of the “hung jury”, where the jury is unable to reach any verdict and a retrial is required.

These concerns should not be overstated. Hung juries are rare in other jurisdictions, which is why some have been able to maintain an absolute unanimity requirement. It has been estimated that if Scottish juries were to hang at the same rate as English ones, the number of retrials annually would be in single figures. Nonetheless, there is unlikely to be much appetite for the introduction of hung juries to Scotland.

That suggests a middle course, where the current requirement of eight votes for conviction might be moderately increased, but with anything short of a new majority (such as 10 or 12 from 15) being considered an acquittal.

In contrast to the majority question, many commentators seem positive about the size of the Scottish jury, perhaps because it is not perceived as being significantly linked to the likelihood of conviction or acquittal. Ignoring jury size would, however, be a risk. As explained above, there is considerable evidence from elsewhere that unanimity requirements rarely prevent juries reaching decisions. In almost all cases juries are able to reach consensus, whether by complete unanimity or something close to it.

All this evidence, however, comes from systems with a 12 person jury. We have almost no evidence on whether a 15 person jury is similarly effective in reaching a consensus when required. It was striking in the recorded deliberations of the participants in the Scottish Jury Research how much less effective deliberation appeared to be in larger juries, with conversations often running in parallel and jurors talking over each other.

Anyone who has served on a committee will know how groups become less effective the larger they get, a point borne out by more general research on group decision making. Some commentators appear to believe that the question of jury size can be answered by asserting that a larger jury allows for more views to be represented. But additional representation may be meaningless if individuals are silenced by ineffective discussion. And the argument cannot simply be that more is better – why not, then, have juries of 20, 25 or 30? A decision about jury size requires acknowledging a tension between diversity of membership and effectiveness of deliberations.

As an aside, it is noticeable that those who praise viewpoint diversity in this context often ignore the weight that is given to individual views in juries elsewhere. In other countries, individual views are of huge significance. In many systems a single juror can prevent what they consider an unjust conviction; in others they need only make common cause with one or two other jurors. In Scotland, the lone juror is readily outvoted.

The significance of the jury size question should, therefore, depend on the rigour with which it is proposed to address the majority question. Those who wish to argue for a particularly strict majority requirement may find that their case becomes more compelling if they are willing to countenance an accompanying reduction in the jury’s size.

A great deal of energy has been spent on defending the not proven verdict, even after its days seemed clearly numbered. This means that little time has been spent discussing changes which its abolition should necessitate. There is now a window of opportunity before legislation is taken through Parliament, which hopefully will not be squandered.