“He was entitled to be regarded as a phonetician well qualified by academic training and practical experience to express an opinion on voice identification. We do not doubt that his judgment, based on close attention to voice quality, voice pitch and the pronunciation of vowels and consonants, would have a value significantly greater than that of the ordinary untutored laymen, as the judgment of a hand-writing expert is superior to that of the man in the street.”
“The phrase ‘expert ad hoc’ seeks to put witnesses like Detective Parsons and PC Fitzpatrick into the traditional category of those qualified to give expert opinion. Whether or not the tag is appropriate, we are clearly of the view that PC Fitzpatrick had ‘special knowledge that the Court did not possess’ … PC Fitzpatrick had acquired the knowledge by lengthy and studious application to material which was itself admissible evidence. To afford the jury the time and facilities to conduct the same research would be utterly impracticable. Accordingly, it was in our judgment legitimate to allow the officer to assist the jury by pointing to what he asserted was happening in the crowded scenes on the film. He was open to cross-examination, and the jury, after proper direction and warnings, were free either to accept or reject his assertions.”
“In our judgment, on the authorities, there are, as it seems to us at least four circumstances in which, subject to the judicial discretion to exclude, evidence is admissible to show and, subject to appropriate directions in the summing up, a jury can be invited to conclude that the defendant committed the offence on the basis of photographic image from the scene of the crime: (i) where the photographic image is sufficiently clear, the jury can compare it with the defendants sitting in the dock …; (ii) where a witness knows the defendant sufficiently well to recognise him as the offender depicted in the photographic image, he can give evidence of this …; (iii) where a witness who does not know the defendant spends substantial time viewing and analysing photographic images from the scene, thereby acquiring special knowledge which the jury does not have, he can give evidence of identification based on a comparison between those images and a reasonably contemporary photograph of the defendant, provided that the images and the photograph are available for the jury …; (iv) a suitably qualified expert with facial mapping skills can give opinion evidence of identification based on comparison between images from the scene, (whether expertly enhanced or not) and a reasonably contemporary photograph of the defendant, provided the images and the photograph are available to the jury …”
“I agree with Mr Moore that there is no direct contradiction between Dr Holmes’ evidence and that of the officer. On the basis of the material submitted to her, Dr Holmes said it was not possible reliably to attribute anything in the recording to particular speakers, but that was as far as she was able to go. She did not, for example, say that the quality of the tape was so poor that not even someone who had spent some time in conversation with a particular individual would be unable reliably to recognise his voice on the recording.”
“Although some of the speech was clearly intelligible much had lower intelligibility or could not be decoded with any degree of certainty. Because of the fragmented nature of the recorded speech and the poor technical quality, it was not possible reliably to attribute utterances to individual speakers.”
“A pre-requisite for my making a speaker-identification is that there is sample of adequate size from the disputed recording that can confidently be attributed to a single speaker. This sample forms the basis for the process of analysis. If it is not possible reliably to attribute utterances to individual speakers then the basis for an analysis is lacking. In the present case, on the basis of the analysis carried out by me in the course of producing the orthographic transcript of the disputed material, I made a judgment that I was not able reliably to attribute utterances to individual speakers, and consequently that it was not appropriate for me to carry out a speech comparison analysis.”
“Further, there is no reason why a particular officer’s recognition of a voice should not be used as a basis for further investigation (no reference specifically to the present case; I am thinking more generally of e.g. cases involving hoax telephone calls made by someone already known to the police). The question here is rather, whether the opinion of a police officer, who is in this context a lay listener, should have any evidential weight in the absence of an expert opinion. The points raised in 1. above should give an indication of the potential issues raised.”