Forensic Evidence in UK Law

If, in such a case, there is sufficient credible evidence, apart from the missing evidence, which, if believed, would justify a safe conviction, then a trial should proceed, leaving the defendant to seek to persuade the jury or magistrates not to convict because evidence which might otherwise have been available was not before the court through no fault of his. Often the absence of a video film or fingerprints or DNA material is likely to hamper the prosecution as much as the defence.

This appellant, as it seems to us, had, clearly and expressly by his conduct, waived his right to be present and to be legally represented.

These various classes of excluded relevant evidence may for ease of exposition be presented under different colours. But in reality they constitute a spectrum, refractions of the single light of a public interest which may outshine that of the desirability that all relevant evidence should be adduced to a court of law.

It is frequently very difficult to tell whether a witness is telling the truth or not; and where there is a conflict of evidence such as there was in the present case, reference to the objective facts and documents, to the witnesses' motives, and to the overall probabilities, can be of very great assistance to a judge in ascertaining the truth.

When, in the judgment of the trial Judge, the quality of the identifying evidence is poor, as for example when it depends solely on a fleeting glance or on a longer observation made in difficult conditions, the situation is very different. The Judge should then withdraw the case from the jury and direct an acquittal unless there is other evidence which goes to support the correctness of the identification.

In cases of this kind, it may, or more often may not, be possible to say that a defendant is innocent, but it is possible to say that he has been wrongly convicted. The common factor in such cases is that something has gone seriously wrong in the investigation of the offence or the conduct of the trial, resulting in the conviction of someone who should not have been convicted.

Where the conduct of an expert alleged to amount to a professional offence under scrutiny by his professional disciplinary body arises out of evidence he has given to a court or other tribunal, it is, therefore, important that that body should fully understand, and assess his conduct in the forensic context in which it arose.