Even in a case where an eye witness recognised an accused, the trial judge should always give an appropriate direction in accordance with R v Turnbull (1977) QB 224 unless, as in the instant case, the nature of the eye witness evidence was such that the direction added nothing of substance to the judge's other directions to the jury on how to approach that evidence. The judge's direction regarding alibi in the instant case had, however, been unfairly prejudicial to the accused because it had undermined the alibi that was the central issue raised in the defence.

[2006] UKPC 34