Whatever the defence and however the case is conducted, where evidence as to identification represents any significant part of the proof of guilt of an offence, the judge must warn the jury as to the dangers of convicting on such evidence where its reliability is disputed. The terms of the warning need not follow any particular formula. But it must be cogent and effective. It must be appropriate to the circumstances of the case. Consequently, the jury must be instructed "as to the factors which may affect the consideration of (the identification) evidence in the circumstances of the particular case". A warning in general terms is insufficient. The attention of the jury "should be drawn to any weaknesses in the identification evidence". Reference to counsel's arguments is insufficient. The jury must have the benefit of a direction which has the authority of the judge's office behind it. It follows that the trial judge should isolate and identify for the benefit of the jury any matter of significance which may reasonably be regarded as undermining the reliability of the identification evidence.[10]
The warning must "isolate and identify for the benefit of the jury any matter of significance which may reasonably be regarded as undermining the reliability of the identification evidence". "The jury must have the benefit of a direction which has the authority of the judge's office behind it." The purpose of the warning is self-evident. It is to draw to the attention of the jury the difficulties in evidence which, because it is so seductive, has so often led to proven miscarriages of justice.[11]
The adequacy of a warning to the jury concerning the dangers of identification evidence is not measured, as such, by its length. It depends on its content, balance and weight. What is required is not a particular set of words or a rigid formula, with a failure in compliance resulting in the verdict being quashed. The law requires that the judge bring his or her authority to bear so that the jury understand that mistakes can occur from genuine but wrongful identification. The warning given must not be "the perfunctory or half-hearted repetition of a formula, and a warning in general terms will not alone be sufficient; the jury should be given careful guidance as to the circumstances of the particular case, and their attention should be drawn to any weaknesses in the identification evidence".
It is in this last respect that the trial judge's summing up was less helpful than it should have been. In this Court, the prosecution accepted that "fuller directions could have been given". The defects relate not just to the two items singled out by the Court of Appeal but also to the more general problem described by Lord Ackner in the Privy Council in Reid (Junior) v The Queen namely the "ghastly risk run in cases of fleeting encounters". In Australia that risk is addressed by requiring that, in a jury trial, the judge explain to the jury how that risk was relevant to the particular case and how the jury were obliged to exercise care because of the law's experience that genuine but erroneous identifications can sometimes be made by honest witnesses.
...Once the identification evidence was admitted, it was imperative, given its obvious and acknowledged weaknesses, that the particular nature of at least the chief of those weaknesses should have been identified and called to the notice of the jury so that the warnings could be related to the weaknesses. Instead, with respect, the warnings were left hanging in the air as general remarks about the imperfections of identification evidence as a category of testimony.
The requirement of particularity is the standard established by this Court in Domican.[12]