Thought for this Day: Balance of Reasonable Doubt

Tuesday, 3 March 2015, 9:07 am
Column: Keith Rankin

I watched the final of series 2 of Broadchurch (TV1) on Sunday. This drama depicted the trial a person the audience already knew to be guilty (from series 1). The defence of the accused was based purely on creating doubt, and the main device for creating the doubt was to suggest that another person, related to the victim, might have been the real culprit.

The criteria for conviction is 'beyond reasonable doubt'. An inferential statistician would define reasonable doubt to normally mean five percent doubt. (One percent under some conditions, maybe if it was a capital crime.) What it means is that the jury is required to acquit if they are 90 percent sure that the defendant was guilty.

In the TV drama it was made clear that the verdict was on the cusp of 'beyond reasonable doubt'. The jury were split, and the court accepted a 10-2 majority verdict as well. Thus what happened was that ten jurors thought there was perhaps a 90 percent chance of guilt, and two jurors thought the chance of guilt was over 95 percent.

In New Zealand we have three cases for which this is relevant. First we have the Teina Pora decision tonight, from the Privy Council in London. As in the Broadchurch case there was a confession; a confession that (as in Broadchurch) probably should not have been admissible evidence. In my view the chance that Pora was guilty of the crime he was convicted of is much less than 95 percent. So, if the process has been correctly followed, Pora should get at least the chance of a retrial as Mark Lundy did.

Then there is the Mark Lundy retrial. It has an eerie sense of being like the trial depicted in Broadchurch, with another person clearly labelled as an alternative perpetrator of the crime. The approach clearly is to use that candidate to create doubt. I of course have no idea whether Lundy was guilty or not. But he may well be acquitted on the grounds that the jury are 90 rather than 95 percent sure of his guilt.

If so, then we will expect face a claim for compensation from Mark Lundy, which brings us to a third current case, the David Bain compensation claim.

Bain may have been acquitted on the same basis, that the jury believed he was guilty on the 'balance of probability' but not 'beyond reasonable doubt'. This is the real grey area of the criminal-justice system.

In David Bain's case, there is only one other credible perpetrator, David's father Robin. Thus what should be happening in the new review is, in effect, Robin Bain being placed on trial with view to being found guilty 'on the balance of probability'. Only then could we assert David's innocence on the balance of probability.

What does the 'balance of probability' mean? It must mean, for David Bain to gain compensation, that the chance that David killed any of his family is less than 40 percent, meaning that the chance that Robin was guilty would be judged to be at least 60 percent. The process can never actually demonstrate David's innocent beyond reasonable doubt.

If David Bain is eventually granted compensation, it will mean, in effect that Robin Bain has been convicted (though not beyond reasonable doubt) and that there remains a 40 percent chance of David's guilt. That's the nature of the process. And if Mark Lundy is acquitted, the alternative candidate is still alive. Would that oblige the alternative candidate to be arrested and tried for the Lundy murders? Certainly any granting of compensation to Lundy would be the equivalent of a conviction (albeit on the balance of probability) of another specifically and publicly identified man.

I think that we (especially the media) should use numbers (ie numerical probabilities, as above) more in helping the public to understand what these niceties of criminal-justice language really mean.

ENDS

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Keith Rankin

Political Economist, Scoop Columnist

Keith Rankin taught economics at Unitec in Mt Albert since 1999. An economic historian by training, his research has included an analysis of labour supply in the Great Depression of the 1930s, and has included estimates of New Zealand's GNP going back to the 1850s.

Keith believes that many of the economic issues that beguile us cannot be understood by relying on the orthodox interpretations of our social science disciplines. Keith favours a critical approach that emphasises new perspectives rather than simply opposing those practices and policies that we don't like.

Keith retired in 2020 and lives with his family in Glen Eden, Auckland.

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