I often wonder whether the law of evidence has developed in the way it has purely because of the adversarial nature of common law litigation or perhaps as a result of our use or abuse of juries.

It is easy to say that the very nature of an adversarial system necessitates a series of specialist rules and that under a civil or administrative law system such complexity is simply not needed. This may be so, but I regard it as unacceptable that our rules have developed to a level of complexity that few have mastered and from which the public can easily cite examples of exclusion that many believe illustrate a system not geared toward achieving justice at all.

It is true, of course, that most issues in life are much more complex than our “she’ll be right” attitude sometimes suggests. So, too, Occam’s razor; while handy at a basic level the most obvious answer may not actually be the logical or reasonable answer in many cases.

Admissibility

These realities aside, I am nonetheless left unsatisfied by my fancy logic driven answers to the question of why evidence was not admitted in particular cases. Don’t get me wrong, I am entirely comfortable with my ability to present such arguments and I am passionately committed to the application of logic and reason in achieving standards of proof. However I am often left somewhat empty by my arguments in a way that recourse to pure logic and reason sometimes does.

If my answers are met with “yeah, but the jury should have had that before them” then I feel left with needing to justify the judge’s assumption of human nature and the inevitable balance made by the judge between probative value and unfair prejudice.

In the Chen case (R v Yun Qing Liu [2015] NZHC 1125), one journalist I spoke to seemed appalled that the judge would even attempt to second guess what a jury might or might not do let alone act as a filter on what they could or could not hear based upon presumptions on their ability to deal with evidence.

In this column I do not want to look at the virtues of juries, the rights or wrongs of a jury system or speculating on their future use. What I do want to talk about for a moment is our love-hate relationship with juries; treated all intelligent and all-knowing at one moment and ignorant and full of prejudices the next.

Role taken seriously

In my experience juries have taken their role incredibly seriously. There will always be exceptions to the rule but I just do not agree that New Zealand juries are full of the unemployed and the elderly (often cited as if these groups are entirely unable to think or act logically and in a considered way). While individually we all have our weaknesses in terms of our ability to reason and consider complex scenarios, the collective ability of a group of 12 is rather more robust. The system recognises this in its presumption that juries can and ought to deal with complex expert evidence.

Sometimes that presumption falters and juries seemingly fail to grasp the intricacies of expert evidence. However, that is not something that lawyers or judges are necessarily better trained or placed to avoid.

At other times the system regards juries as particularly prone to bias, skewed reasoning or applying flawed logic. The assessment of unfair prejudice by a judge when determining admissibility is a prime example of where assumptions as to the ability of juries to deal with nuanced issues arises.

I am just not convinced that juries are unable to differentiate the use of evidence, say, in the case of a victim statement of perceived guilt (the Chen case) or the admission of previous convictions.

The trust question

So my rhetorical question is, do we trust juries enough or too much?

At base, the perceived danger in criminal trials in regards to juries is that without very careful monitoring evidence may be adduced that does little other than creating a case based upon the moral character of the accused. Even despicable human beings, the immoral, the self-professed thieves, rapist and murders deserve a fair trial. It is, therefore, in the area of character evidence (veracity and propensity) that special care is taken with the admission or exclusion of evidence.

But are juries completely incapable of understanding or following a direction from a judge as to the dangers of such evidence? Are they all so persuaded or obsessed with drawing moral judgments of the character of an accused? Do they really believe that if you are charged you must be guilty?

We expect juries to understand some highly complex directions at times (the old direction on provocation is a prime example) so why should we doubt their ability to be on guard against bias, moral stereotyping and sloppy thinking?

The issue of jury competence is a vexed one often augmented by polarised thinking. This column will give rise to many polarised views, I am sure, but my question still remains, does our recourse to legal logic always result in a just outcome on admissibility?

Dr Chris Gallavin is an Associate Professor and Dean of Law at Canterbury University. He has published extensively on criminal justice and on evidence and procedure in particular. He is the author of the appellant handbook, Evidence(LexisNexis, Wellington, 2008), and regularly undertakes consultant work in the area of the law of evidence.