4. Identification

R v Turnbull was not one appeal. The Court of Appeal, Lord Widgery CJ, heard several identification cases together and laid down a practice direction. It applies when the prosecution depends wholly or substantially on identification evidence which the defence says is mistaken. It does not apply where the accused admits he was there, and the only question is what he did.

The judge must warn the jury of the special need for caution before convicting on identification. He must tell them that a convincing witness can be mistaken, and that more than one convincing witness can be mistaken. He must then take the jury through the circumstances: how long the witness had the person under observation, at what distance, in what light, whether the view was obstructed, whether the witness already knew the person, how long after the sighting the identification was made, and whether there is any material discrepancy between the description given to the police and the appearance of the accused.

If the quality of the identification is good, the jury may be left to assess it, after the warning. If the quality is poor, a fleeting glimpse, or a longer look in difficult conditions, the judge should withdraw the case unless there is other evidence that supports the identification. Supporting evidence can be a lie told by the accused, an association with the place, forensic evidence, or another identifier. It does not have to be corroboration in the Baskerville sense. The judge must point out evidence that the jury might think is supporting when it is not. A false alibi is not automatically support. It may be, if the jury is sure the alibi was put forward to deceive them about presence at the scene. Photographs and video still call for the warning. They do not replace it.

Voice identification is not governed by Turnbull. The illustration is R v Hersey. The robbers wore balaclavas. One of them talked to the victims for about fifteen minutes. There was a voice parade of twelve voices, a voir dire, and an expert who said the pitch and the reading style singled the accused out. The evidence was admitted, and he was convicted. The caution is real. The legal rule is not the Turnbull direction.