Evidence that might be wrong

I found it unsettling to read of scepticism about the prospects of success on an appeal referred to the Court of Appeal after consideration, by a retired judge, of fresh evidence.

As the matter is to be before the Court of Appeal again I say no more about that case. In fact, I know no more about it than anyone who has looked at newspapers or listened to news reports on the radio.

How should a fact-finder, a judge or a jury, deal with the evidence of a witness who might be mistaken?

Many kinds of testimony have an inherent risk of being wrong through mistake.

Should this evidence be assessed by comparison with other evidence on the same point and then be accepted or rejected before all the evidence is considered as a whole? Or, should assessment of the risk of error be suspended until all the evidence has been given and a verdict has to be decided on?

The difference is that suspension of decision on risk of error prevents the fact-finder from forming a theory about the result before all the evidence has been given. A premature theory can bias the assessment of other evidence.

It is unsafe to assess a case as strong before all the evidence in the trial has been given. Nevertheless, we expect a prosecution case to appear strong before a trial, for we do not want people to be prosecuted on weak evidence.

Juries are routinely told by judges that they must suspend judgment until after they have heard all the evidence, the addresses by counsel and the instructions on the law from the judge.

But, and here there is a risk of error, juries are also told that they must, in looking at all the evidence, decide what they accept and what they reject, and then decide whether the evidence they accept is sufficient to prove the prosecutor’s case beyond reasonable doubt.

This suggests a two-step approach to the evidence as a whole. First is the filtering out of evidence that, on an overview, the fact-finder rejects because it must be wrong. For example, evidence of a cast-iron alibi may mean that an eyewitness identification of the defendant at the scene must be wrong. The eyewitness evidence does not, in those circumstances, carry a possibility that it may be right. Second, considering all the remaining evidence, some may obviously be right, for example because there was no dispute about it, and some may most likely be right but with a smaller possibility that it is wrong. This sort of evidence is not taken on an all-or-nothing basis because the possibility of it being wrong is relevant to its probative value and to whether on the whole of the evidence there is a reasonable doubt about the defendant’s guilt.

I wouldn’t be as sceptical as the folk mentioned in the news report cited above. Judges are, in my experience of over 40 years of looking at them, fiercely independent-minded people. Any barrister who has struggled to get a judge to follow precedent will agree. Being trained as lawyers, they take pleasure in arguing, and they certainly don’t expect their opinions to be automatically accepted just because they are judges or retired judges. Their overriding concern is to make the law work rationally and justly.