House of Lords
Session 1996-97
Publications on the Internet

Judgments -- Director of Public Prosecutions v. McKeown
Director of Public Prosecutions v. Jones


  Lord Goff of Chieveley   Lord Mustill   Lord Steyn   Lord Hoffmann   Lord Clyde   










My Lords,

          I have read in draft the speech prepared by my noble and learned friend Lord Hoffmann. For the reasons he gives I would allow the Director's appeals in both cases.


My Lords,

          I have had the advantage of reading in draft the speech prepared by my noble and learned friend Lord Hoffmann. For the reasons which he gives I would allow the Director's appeals in both cases.


My Lords,

          I have read in draft the speech prepared by my noble and learned friend Lord Hoffmann. For the reasons he gives I would allow the Director's appeals in both cases.


My Lords,

          These two appeals concerning convictions under the Road Traffic Act 1988, one for driving with an excessive proportion of alcohol in the breath and the other for failing without reasonable excuse to provide a specimen of breath, both arise out of the fact that in late 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 case was there any dispute about the correct time at which the Intoximeter was used; in fact, the precise time was not a matter of any importance. In the one case the Intoximeter recorded that the motorist had twice the prescribed limit of alcohol in both specimens of her breath; in the other, the first specimen was more than four times the prescribed limit, after which the motorist deliberately refused to provide a second. Nevertheless the Divisional Court accepted that the inaccuracy of the clock reading vitiated both convictions and against that decision the Director of Public Prosecutions appeals to your Lordships' House.

          By section 5(1) of the Act of 1988 it is an offence to drive a motor vehicle on a road after consuming so much alcohol that the proportion in his breath exceeds the prescribed limit of 35 microgrammes of alcohol in 100 millilitres of breath. By section 7(1), a constable investigating whether a person has committed an offence under section 5 may require him to provide two specimens of breath for analysis by means of a device of a type approved by the Secretary of State and by section 7(6) a person who without reasonable excuse fails to provide a specimen when required to do so pursuant to subsection (1) is guilty of an offence.

          The Lion Intoximeter 3000 is a device approved by the Secretary of State for the purposes of section 7(1). It consists of an analyser which measures the alcohol content of the breath by means of an electrical signal; a computer which converts the signal into digital form with a visual display on which the result of the test is shown and a printer on which it can be printed out; and a breath simulator which provides air containing a measured quantity of alcohol so that the constable operating the machine may check whether it is calibrating correctly. The standard procedure is for the machine to be tested before and after the analysis of the two specimens provided by the motorist.

          The usual way in which evidence of the proportion of alcohol in the breath is proved in court is by certificate under section 16 of the Road Traffic Offenders Act 1988. This provides as follows:

    "(1) Evidence of the proportion of alcohol . . . in a specimen of breath . . . may, subject to subsections (3) and (4) below . . . be given by the production of a document or documents purporting to be . . . (a) a statement automatically produced by the device by which the proportion of alcohol in a specimen of breath was measured and a certificate signed by a constable (which may but need not be contained in the same document as the statement) that the statement relates to a specimen provided by the accused at the date and time shown in the statement . . .

    "(3) Subject to subsection (4) below--(a) a document purporting to be such a statement or such a certificate (or both such a statement and such a certificate) as is mentioned in subsection 1(a) above is admissible in evidence on behalf of the prosecution in pursuance of this section only if a copy of it either has been handed to the accused when the document was produced or has been served on him not later than seven days before the hearing . . . .

    "(4) A document purporting to be a certificate (or so much of a document as purports to be a certificate) is not so admissible if the accused, not later than three days before the hearing or within such further time as the court may in special circumstances allow, has served notice on the prosecutor requiring the attendance at the hearing of the person by whom the document purports to be signed."

          The section is a specialised exception to the hearsay rule which, on compliance with its conditions, enables evidence which the constable could have given orally to be given instead by a certificate admissible on mere production. But the requirement that the certificate and statement be served on the accused and that they should not be admissible if the accused gives notice that he requires the constable who signed the certificate to attend the hearing means that the procedure is for practical purposes consensual. If such notice is given, or the prosecution is unable to comply with the conditions, the prosecution must prove its case by other admissible evidence.

          This will in practice mean calling the officer who operated that Intoximeter to testify to the results of the test by reference to what he saw on the visual display and what the machine printed out. Such first-hand evidence of what was displayed or recorded on a mechanical measuring device is real evidence admissible at common law: see Castle v. Cross [1984] 1 W.L.R. 1372, applying The Statue of Liberty [1968] 1 W.L.R. 739. But when the measuring device, as in this case, includes a computer, the evidence is not admissible unless it satisfies the requirements of section 69 of the Police and Criminal Evidence Act 1984:

    "(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 -

       (a) that there are no reasonable grounds for believing that the statement is inaccurate because of improper use of the computer; (b) that at all material times the computer was operating properly, or if not, that any respect in which it was not operating properly or was out of operation was not such as to affect the production of the document or the accuracy of its contents."

          These provisions are supplemented by paragraph 8 of Schedule 3:

    "8. In any proceedings where it is desired to give a statement in evidence in accordance with section 69 above, a certificate--

        (a) identifying the document containing the statement and describing the manner in which it was produced; (b) giving such particulars of any device involved in the production of that document as may be appropriate for the purpose of showing that the document was produced by a computer; (c) dealing with any of the matters mentioned in subsection (1) of section 69 above; and (d) purporting to be signed by a person occupying a responsible position in relation to the operation of the computer, shall be evidence of anything stated in it; and for the purposes of this paragraph it shall be sufficient for a matter to be stated to the best of the knowledge and belief of the person stating it."

          That is the statutory background to the two cases under appeal. Although both are concerned with the effect of the inaccuracy of the time display upon the validity of the conviction, the offences charged were different and the legal issues are not the same. I shall therefore consider first the case of Ms McKeown, who was convicted under section 5(1) and then that of Mr. Jones, who was convicted under section 7(6).

          Late on 21 July 1992 Ms McKeown was observed to be driving erratically in Liverpool Road, Widnes, arrested on suspicion of being over the limit and taken to Widnes Police Station. There she was required to take a breath test. The Lion Intoximeter 3000 was operated by Sergeant O'Dell. He tested the machine and it calibrated correctly. By this time it was about a quarter after midnight; the sergeant's watch said 00.13 a.m. But the time display on the machine read 23:00. Part of the discrepancy was explained by the fact that, as the print-out made plain, the machine was set to GMT. But there was no explanation of the balance. Ms McKeown provided the required two specimens, both of which registered 78; well in excess of the prescribed limit of 35. Afterwards Sergeant O'Dell tested the machine again and once more it calibrated correctly. He filled in the standard form of witness statement for use in such cases, attaching the print-out from the Intoximeter but noting on his statement 'Time shown on print out is 1 hr 13 mins slow".

          Ms McKeown was charged under section 5(1). She was served with the statement of Sergeant O'Dell and also a statement of Dr Paul Williams, a director of Lion Laboratories Ltd, which supplies the Intoximeter to the police. It said that the alcohol analytical system and breath sampling system were separate from the circuitry which controlled the accuracy of the clock. Inaccuracy in the time display could have absolutely no effect on the accuracy of the readings obtained on breath samples.

          On 27 November 1992, shortly before the case was due to be heard, Ms McKeown's solicitors wrote to the Crown Prosecution Service saying that the statement of Dr Williams "cannot be accepted." They also asked to be supplied with "all relevant design documents and the circuit diagram." On 7 December 1992 the CPS wrote back saying that Dr Williams would give evidence but refusing to produce diagrams or documents. In the event the case did not come on till 20 April 1993, but there was no application until the hearing, when the defence applied for an order that Dr Williams should produce the documents and diagrams. The justices refused the application.

          As the time inaccuracy meant that Sergeant O'Dell was unable to certify, in accordance with section 16 of the Road Traffic Offenders Act 1988, that the statement automatically produced by the Intoximeter related to "a specimen provided by the accused at the date and time shown in the statement", he was called to give evidence and testified to the conduct of the test and the readings on the visual display and print-out which I have described. Dr Williams also gave evidence. He said that he was not an electronics expert and did not understand the circuitry of the Intoximeter clock but that the clock had no bearing on the accuracy of the breath readings. The justices accepted this evidence and found, as later recorded in the case stated, that the Intoximeter was not affected by the clock and that the statements as to the breath readings it produced were accurate.

          It is convenient at this stage to deal with two procedural questions which were raised by the justices in the case stated. The first was whether they were right to refuse the application for production of documents. The application was made under section 97(1) of the Magistrates' Court Act 1980:

    "Where a justice of the peace. . . is satisfied that any person . . . is likely to be able to . . . produce any document . . . likely to be material evidence . . . at the summary trial of an information . . . and that that person . . . will not voluntarily produce the document . . . the justice shall issue a summons directed to that person requiring him to attend before the court . . . to produce the document. . . "