Director of Public Prosecutions v McKeown

Section 69 of the Police and Criminal Evidence Act 1984 governs whether a computer properly processed, stored and reproduced the information used to generate a statement tendered in evidence. A malfunction affects admissibility only if it is material to that process or to the accuracy of the relevant statement. An unrelated inaccuracy in a computer clock does not render otherwise reliable breath-analysis results inadmissible.

A device remains of a type approved for breath analysis despite an immaterial defect. A reasonable excuse for failing to provide a specimen must have a causal connection with the failure. An unnoticed defect cannot supply that connection.

These conjoined appeals concerned convictions under the Road Traffic Act 1988. Ms McKeown was convicted of driving with excess alcohol, and Mr Jones was convicted of failing without reasonable excuse to provide a second breath specimen. The Lion Intoximeter 3000 used in both cases displayed a time about one hour and a quarter slow, although the justices found that its breath-analysis function was accurate.

The Divisional Court held that the inaccurate clock vitiated both convictions. The Director of Public Prosecutions appealed. The central issues were whether the Intoximeter results satisfied section 69 of the Police and Criminal Evidence Act 1984, whether the machine remained an approved type of device, and whether the clock error could constitute a reasonable excuse for failing to provide a specimen.

Appeals allowed unanimously. Lord Hoffmann delivered the leading speech. Lord Goff of Chieveley, Lord Mustill, Lord Steyn and Lord Clyde agreed with his reasons.

1. Per Lord Hoffmann, section 69 of the Police and Criminal Evidence Act 1984 has a limited purpose. It requires positive evidence that a computer properly processed, stored and reproduced the information it received. It does not determine whether the information supplied to the computer was accurate or whether the resulting statement was probably true. Those matters ordinarily concern evidential weight.

2. A malfunction is material under section 69(1)(b) only if it affects the computer's processing, storage or retrieval of the information used to generate the statement tendered in evidence. The statutory reference to production of the document and accuracy of its contents is confined to aspects material to the accuracy of that statement. The inaccurate clock did not affect the breath-analysis system. The certificate under paragraph 8 of Schedule 3, together with the accepted evidence about the machine's operation, therefore established admissibility.

3. The justices properly refused Ms McKeown's application under section 97(1) of the Magistrates' Courts Act 1980. That provision does not permit disguised discovery. The suggested relevance of the circuit diagrams was speculative, and no evidential foundation showed that they were likely to be material. Dr Williams could also give admissible expert evidence based on his practical familiarity with Intoximeters, despite lacking expertise in electronics.

4. In Mr Jones's case, the inaccurate clock did not prevent the machine from being a device of a type approved under section 7(1) of the Road Traffic Act 1988. Section 7(3)(b) itself contemplates that an individual device may be unreliable while remaining of an approved type.

5. A reasonable excuse under section 7(6) must bear a causal connection to the failure to provide a specimen. Mr Jones did not know of the clock error, so it could not explain his refusal. Even awareness of the error would not have been a reasonable excuse because it did not make the breath-analysis exercise pointless. The computer evidence that the second test aborted was admissible for the same reasons as in Ms McKeown's case.

The Director's appeals in both cases were allowed.

1. House of Lords: Allowed the Director of Public Prosecutions' conjoined appeals unanimously and rejected the proposition that the inaccurate clock vitiated either conviction.
2. Divisional Court of the Queen's Bench Division: Accepted that the clock inaccuracy vitiated both convictions and decided against the Director.
3. Magistrates' courts: Convicted Ms McKeown under section 5(1) and Mr Jones under section 7(6) of the Road Traffic Act 1988.