Law Report: Computer evidence not vitiated by faulty clock

Director of Public Prosecutions v McKeown; DPP v Jones; House of Lords (Lord Goff of Cheiveley, Lord Mustill, Lord Steyn, Lord Hoffmann, Lord Clyde) 20 February 1997

A computer-generated statement was admissible in evidence under section 69(1) of the Police and Criminal Evidence Act 1984 notwithstanding that a part of the computer, in this case its clock, appeared to be malfunctioning, so long as there was positive evidence that the computer had properly processed, stored and reproduced the information contained in the statement.

The House of Lords allowed appeals by the Director of Public Prosecution against decisions of the Queen's Bench Divisional Court, on 27 May 1994, quashing convictions by the Widnes Justices of Sharon McKeown on 20 April 1993 and of Christopher Jones on 4 May 1993 for drink-driving offences.

Section 69 of the 1984 Act provided:

(1) In any proceedings, a statement in a document produced by a computer shall not be admissible as evidence of any fact stated therein unless it is shown . . . (b) that at all material times the computer was operating properly, or if not, that any respect in which it was not operat-

ing properly or was out of operation

was not such as to affect the production of the document or the accuracy of its contents . . .

In July 1992 the computer clock in the Lion Intoximeter 3000 in use at Widnes Police Station was displaying a time about an hour and a quarter slow. In neither appeal was there any dispute about the correct time at which the Intoximeter was used. The Divisional Court nevertheless held that the inaccuracy of the clock reading invalidated the evidence on which both convictions were based.

Anthony Scrivener QC and Steven Everett (Crown Prosecution Service) for the Crown; Michael Beloff QC and Renee Calder (Byrne Frodsham & Co, Widnes) for Ms McKeown; Nigel J. Ley (Nyland & Beattie, Widnes) for Mr Jones.

Lord Hoffmann said that section 69 did not require the prosecution to show that the statement was likely to be true. Whether it was likely to be true or not was a question of weight for the justices or jury.

All that section 69 required as a condition of the admissibility of a computer-generated statement was positive evidence that the computer had properly processed, stored and reproduced whatever information it received. It was concerned with the way in which the computer had dealt with the information to generate the statement which was being tendered as evidence of the fact which it stated.

The language of section 69(1) recognised that a computer might be malfunctioning in a way which was not relevant to the purpose of the exclusionary rule. It could not therefore be argued that any malfunction was sufficient to cast doubt upon the capacity of the computer to process information correctly.

What then was contemplated as the distinction between a relevant and an irrelevant malfunction? There was only one possible answer. A malfunction was relevant if it affected the way in which the computer processed, stored or retrieved the information used to generate the statement tendered in evidence. Other malfunctions did not matter.

It followed that the words "not such as to affect the production of the document or the accuracy of its contents" had to be read subject to the overall qualification that the paragraph was referring to those aspects of the document or its contents which were material to the accuracy of the statement tendered in evidence.

The justices had a certificate signed by a police sergeant under paragraph 8 of Schedule 3 to the 1984 Act stating that to the best of his knowledge and belief the requirements of section 69(1) had been complied with. In the absence of contrary evidence, they were entitled to accept that certificate as sufficient to satisfy section 69(1).

The question then was whether they were obliged to regard the inaccuracy of the clock display as contrary evidence. They also had evidence, which they were entitled to accept, that the clock display was not affecting the proper functioning of the computer in processing the information from the breath analyser. Having accepted that evidence, there was nothing to displace the effect of the certificate.

Paul Magrath, Barrister