“This comparison therefore offers a level of support for the allegation that Dean Atkins and the offender are one and the same person, between ‘it lends support’ and ‘lends strong support’ to that conclusion. But you should remember this, that, as Mr Neave conceded, there is no database which would enable him to give a statistical analysis and so his scale is based on his own experience and expertise and, he added, in this case on the fact that he was able to exclude a large number of people, including one who was very similar to Dean Atkins, his brother Michael.”
“We do not however wish to pass from this appeal without making general observations about the use of facial imaging and mapping expert evidence of a reliable kind. Mr Harrow, like some other facial imaging and mapping experts, said that comparison of the facial characteristics provided ‘strong support for the identification of the robber as the appellant’. No evidence was led of the number of occasions on which any of the six facial characteristics identified by him as ‘the more unusual and thus individual’ were present in the general population, nor as to the frequency of the occurrence in the general population of combinations of these or any other facial characteristics. Mr Harrow did not suggest that there was any national database of facial characteristics or any accepted mathematical formula, as in the case of fingerprint comparison, from which conclusions as to the probability of occurrence of particular facial characteristics of combinations of facial characteristics could safely be drawn. This court is not aware of the existence of any such database or agreed formula. In their absence any estimate of probabilities and any expression of the degree of support provided…..must be only the subjective opinion of the facial imaging or mapping witness. There is no means of determining objectively whether or not such an opinion is justified. Consequently, unless and until a national database or agreed formula or some other such objective measure is established, this court doubts whether such opinions should ever be expressed by facial imaging or mapping witnesses. The evidence of such witnesses, including opinion evidence, is of course both admissible and frequently of value to demonstrate to a jury with if necessary enhancement techniques afforded by specialist equipment, particular facial characteristics or combinations of such characteristics so as to permit the jury to reach its own conclusion….but on the state of the evidence in this case, and if this court’s understanding of the current position is correct in other cases too, such evidence should stop there.”
“There is limited information but I think the exhibits reveal that there is support for the view that the robber and the suspect are the same man on count 2, but it is not anything like as strong as the support on count 1.”
“But since counsel can bring the witness so close to opining on the ultimate issue that the inference as to his view is obvious, the rule can only be….a matter of form rather than substance. In our view an expert is called to give his opinion and he should be allowed to do so.”
“There is no rule…that in a case such as the present an expert witness cannot go further than saying ‘there are the following similarities’ leaving the ultimate decision to the jury, as opposed to the expert witness actually giving a view as to the degree of probability of the images being the same.”
“A skill or expertise can be recognised and respected and thus satisfy the conditions for admissible expert evidence, although the discipline is not susceptible to this sort of scientific discipline.”