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You are here: BAILII >> Databases >> The Law Commission >> Evidence in Criminal Proceedings: Hearsay and related topics [1997] EWLC 245(13) (19 June 1997)
URL: http://www.bailii.org/ew/other/EWLC/1997/245(13).html
Cite as: [1997] EWLC 245(13)
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PART XIII
COMPUTER EVIDENCE
13.1 In Minors Steyn J summed up the major problem posed for the rules of evidence by computer output:
Often the only record of the transaction, which nobody can be expected to remember, will be in the memory of a computer. If computer output cannot relatively readily be used as evidence in criminal cases, much crime (and notably offences involving dishonesty) would in practice be immune from prosecution. On the other hand, computers are not infallible. They do occasionally malfunction. Software systems often have "bugs". Realistically, therefore, computers must be regarded as imperfect devices. (1)
13.2 The legislature sought to deal with this dilemma by section 69 of PACE, (2) which imposes important additional requirements that must be satisfied before computer evidence is adduced whether it is hearsay or not. (3)
13.3 In practice, a great deal of hearsay evidence is held on computer, (4) and so section 69 warrants careful attention. It must be examined against the requirement that the use of computer evidence should not be unnecessarily impeded, while giving due weight to the fallibility of computers.
PACE, SECTION 69
13.4 In the consultation paper we dealt in detail with the requirements of section 69: (5) in essence it provides that a document produced by a computer may not be adduced as evidence of any fact stated in the document unless it is shown that the computer was properly operating and was not being improperly used. (6) If there is any dispute as to whether the conditions in section 69 have been satisfied, the court must hold a trial within the trial to decide whether the party seeking to rely on the document has established the foundation requirements of section 69.
13.5 In essence, the party relying on computer evidence must first prove that the computer is reliable or, if the evidence was generated by more than one computer, that each of them is reliable. (7) This can be proved by tendering a written certificate, (8) or by calling oral evidence. (9) It is not possible for the party adducing the computer evidence to rely on a presumption that the computer is working correctly. (10) It is also necessary for the computer records themselves to be produced to the court. (11)
The problems with the present law
13.6 In the consultation paper we came to the conclusion that the present law was unsatisfactory, for five reasons. (12)
13.7 First, section 69 fails to address the major causes of inaccuracy in computer evidence. As Professor Tapper has pointed out, "most computer error is either immediately detectable or results from error in the data entered into the machine". (13)
13.8 Secondly, advances in computer technology make it increasingly difficult to comply with section 69: it is becoming "increasingly impractical to examine (and therefore certify) all the intricacies of computer operation". (14) These problems existed even before networking became common.
13.9 A third problem lies in the difficulties confronting the recipient of a computer-produced document who wishes to tender it in evidence: the recipient may be in no position to satisfy the court about the operation of the computer. It may well be that the recipients opponent is better placed to do this. (15)
13.10 Fourthly, it is illogical that section 69 applies where the document is tendered in evidence, (16) but not where it is used by an expert in arriving at his or her conclusions, (17) nor where a witness uses it to refresh his or her memory. (18) If it is safe to admit evidence which relies on and incorporates the output from the computer, it is hard to see why that output should not itself be admissible; and conversely, if it is not safe to admit the output, it can hardly be safe for a witness to rely on it. (19)
13.11 At the time of the publication of the consultation paper there was also a problem arising from the interpretation of section 69. It was held by the Divisional Court in McKeown v DPP (20) that computer evidence is inadmissible if it cannot be proved that the computer was functioning properly even though the malfunctioning of the computer had no effect on the accuracy of the material produced. Thus, in that case, computer evidence could not be relied on because there was a malfunction in the clock part of an Intoximeter machine, although it had no effect on the accuracy of the material part of the printout (the alcohol reading). On appeal, this interpretation has now been rejected by the House of Lords: only malfunctions that affect the way in which a computer processes, stores or retrieves the information used to generate the statement are relevant to section 69. (21)
13.12 In coming to our conclusion that the present law did not work satisfactorily, we noted that in Scotland, some Australian states, (22) New Zealand, the United States and Canada, there is no separate scheme for computer evidence, and yet no problems appear to arise. (23) Our provisional view was that section 69 fails to serve any useful purpose, and that other systems operate effectively and efficiently without it. (24)
13.13 We provisionally proposed that section 69 of PACE be repealed without replacement. (25) Without section 69, a common law presumption comes into play:
In the absence of evidence to the contrary, the courts will presume that mechanical instruments were in order at the material time. (26)
13.14 Where a party sought to rely on the presumption, it would not need to lead evidence that the computer was working properly on the occasion in question unless there was evidence that it may not have been in which case the party would have to prove that it was (beyond reasonable doubt in the case of the prosecution, and on the balance of probabilities in the case of the defence). The principle has been applied to such devices as speedometers (27) and traffic lights, (28) and in the consultation paper we saw no reason why it should not apply to computers.
The response on consultation
13.15 On consultation, the vast majority of those who dealt with this point agreed with us. A number of those in favour (29) said that section 69 had caused much trouble with little benefit.
13.16 The most cogent contrary argument against our proposal came from David Ormerod. (30) In his helpful response, (31) he contended that the common law presumption of regularity may not extend to cases in which computer evidence is central. He cites the assertion of the Privy Council in Dillon v R (32) that "it is well established that the courts will not presume the existence of facts which are central to an offence". If this were literally true it would be of great importance in cases where computer evidence is central, such as Intoximeter cases. (33) But such evidence has often been permitted to satisfy a central element of the prosecution case. Some of these cases were decided before section 69 was introduced; (34) others have been decided since its introduction, but on the assumption (now held to be mistaken) (35) that it did not apply because the statement produced by the computer was not hearsay. (36) The presumption must have been applicable; yet the argument successfully relied upon in Dillon (37) does not appear to have been raised.
13.17 It should also be noted that Dillon was concerned not with the presumption regarding machines but with the presumption of the regularity of official action. (38) This latter presumption was the analogy on which the presumption for machines was originally based; but it is not a particularly close analogy, and the two presumptions are now clearly distinct.
13.18 Even where the presumption applies, it ceases to have any effect once evidence of malfunction has been adduced. The question is, what sort of evidence must the defence adduce, and how realistic is it to suppose that the defence will be able to adduce it without any knowledge of the working of the machine? On the one hand the concept of the evidential burden is a flexible one: a party cannot be required to produce more by way of evidence than one in his or her position could be expected to produce. It could therefore take very little for the presumption to be rebutted, if the party against whom the evidence was adduced could not be expected to produce more. For example, in Cracknell v Willis (39) the House of Lords held that a defendant is entitled to challenge an Intoximeter reading, in the absence of any signs of malfunctioning in the machine itself, by testifying (or calling others to testify) about the amount of alcohol that he or she had drunk.
13.19 On the other hand it may be unrealistic to suppose that in such circumstances the presumption would not prevail. In Cracknell v Willis Lord Griffiths said:
If Parliament wishes to provide that either there is to be an irrebuttable presumption that the breath testing machine is reliable or that the presumption can only be challenged by a particular type of evidence then Parliament must take the responsibility of so deciding and spell out its intention in clear language. Until then I would hold that evidence which, if believed, provides material from which the inference can reasonably be drawn that the machine was unreliable is admissible. (40)
But his Lordship went on:
I am myself hopeful that the good sense of the magistrates and the realisation by the motoring public that approved breath testing machines are proving reliable will combine to ensure that few defendants will seek to challenge a breath analysis by spurious evidence of their consumption of alcohol. The magistrates will remember that the presumption of law is that the machine is reliable and they will no doubt look with a critical eye on evidence such as was produced by Hughes v McConnell (41) before being persuaded that it is not safe to rely upon the reading that it produces. (42)
13.20 Lord Goff did not share Lord Griffiths optimism that motorists would not seek to challenge the analysis by spurious evidence of their consumption of alcohol, but did share his confidence in the good sense of magistrates who, with their attention drawn to the safeguards for defendants built into the Act , will no doubt give proper scrutiny to such defences, and will be fully aware of the strength of the evidence provided by a printout, taken from an approved device, of a specimen of breath provided in accordance with the statutory procedure.
13.21 These dicta may perhaps be read as implying that evidence which merely contradicts the reading, without directly casting doubt on the reliability of the device, may be technically admissible but should rarely be permitted to succeed. However, it is significant that Lord Goff referred in the passage quoted to the safeguards for defendants which are built into the legislation creating the drink-driving offences. (44) In the case of other kinds of computer evidence, where (apart from section 69) no such statutory safeguards exist, we think that the courts can be relied upon to apply the presumption in such a way as to recognise the difficulty faced by a defendant who seeks to challenge the prosecutions evidence but is not in a position to do so directly. The presumption continues to apply to machines other than computers (and until recently was applied to non-hearsay statements by computers) without the safeguard of section 69; and we are not aware of any cases where it has caused injustice because the evidential burden cast on the defence was unduly onerous. Bearing in mind that it is a creature of the common law, and a comparatively modern one, we think it is unlikely that it would be permitted to work injustice.
13.22 Finally it should not be forgotten that section 69 applies equally to computer evidence adduced by the defence. A rule that prevents a defendant from adducing relevant and cogent evidence, merely because there is no positive evidence that it is reliable, is in our view unfair.
Our recommendation
13.23 We are satisfied that section 69 serves no useful purpose. We are not aware of any difficulties encountered in those jurisdictions that have no equivalent. We are satisfied that the presumption of proper functioning would apply to computers, thus throwing an evidential burden on to the opposing party, but that that burden would be interpreted in such a way as to ensure that the presumption did not result in a conviction merely because the defence had failed to adduce evidence of malfunction which it was in no position to adduce. We believe, as did the vast majority of our respondents, that such a regime would work fairly. We recommend the repeal of section 69 of PACE.
(45) (Recommendation 50)
FOOTNOTES TO PART XIII
(1)[1989] 1 WLR 441, 443DE.
(2)The text of this section is set out in Appendix B.
(3)Shephard [1993] AC 380.
(4)Eg shop till rolls (Shephard [1993] AC 380), and building society records (Minors [1989] 1 WLR 441).
(5)Paras 14.3 14.9 of the consultation paper.
(6)But a computer is not regarded as failing this test where it is designed to produce a slightly inaccurate result. In Ashton v DPP (1996) 160 JP 336 a Lion Intoximeter reading of the appellants alcohol level added the words "trace acetone" to show that it might not be wholly accurate, but was held admissible because this was the way in which the device was designed to work.
(7)Cochrane [1993] Crim LR 48.
(8)PACE, Sched 3, para 8.
(9)PACE, Sched 3, para 9.
(10)Shephard [1993] AC 380, 384E, per Lord Griffiths, with whom Lords Emslie, Roskill, Ackner and Lowry agreed.
(11)Burr v DPP [1996] Crim LR 324.
(12)Paras 14.10 14.22 of the consultation paper.
(13)C Tapper, "Discovery in Modern Times: A Voyage around the Common Law World" (1991) 67 Chicago-Kent Law Review 217, 248.
(14)S Castell, "Evidence and Authorisation: is EDI [Electronic Data Interchange] legally reliable?" (1990) 6(5) Computer Law and Security Report 2.
(15)C Tapper, "Evanescent Evidence" (1993) 1(1) International Journal of Information and Technology Law 35, 52.
(16)Shephard [1993] AC 380.
(17)Golizadeh [1995] Crim LR 232.
(18)Sophocleous v Ringer [1988] RTR 52.
(19)See Professor D J Birchs commentary on Sophocleous v Ringer at [1987] Crim LR 423.
(20)[1995] Crim LR 69.
(21)DPP v McKeown; DPP v Jones [1997] 1 WLR 295. It was also doubted whether the clock could properly be regarded as part of the computer: p 303F, per Lord Hoffmann, with whom their Lordships agreed.
(22)New South Wales and Tasmania, as well as the Commonwealth (federal) jurisdiction.
(23)The VERDICT Report (1987) p 84.
(24)See para 14.32 of the consultation paper.
(25)Ibid.
(26)Phipson, para 23-14, approved by the Divisional Court in Castle v Cross [1984] 1 WLR 1372, 1377B, per Stephen Brown LJ.
(27)Nicholas v Penny [1950] 2 KB 466.
(28)Tingle Jacobs & Co v Kennedy [1964] 1 WLR 638n.
(29)The Inland Revenue, the Post Office, the Crown Prosecution Service, BT and the Department of Trade and Industry.
(30)Lecturer in Law at the University of Nottingham.
(31)"Proposals for the Admissibility of Computer Evidence" (Oct/Nov 1995) Comput & Law 22.
(33)The Intoximeter is a computer which is currently subject to the provisions of s 69: R v Medway Magistrates Court, ex p Goddard [1995] RTR 206.
(34)Eg Castle v Cross [1984] 1 WLR 1372.
(35)Shephard [1993] AC 380.
(36)Eg Spiby (1990) 91 Cr App R 186; Neville [1991] Crim LR 288.
(37)Which was not a new argument: the earliest authority relied on was Willis (1872) 12 Cox CC 164.
(38)The case concerned a prison officers liability for negligently permitting an escape, and the issue was whether the prosecution could rely on a presumption that the prisoners were in lawful custody.
(39)[1988] AC 450.
(40)Ibid, at p 468CD.
(41)[1985] RTR 244, where there was considerable evidence (apart from the Intoximeter reading) that the defendant had been very drunk, but the magistrates accepted his evidence that he had drunk only three pints of shandy. The Divisional Courts decision that the reliability of the Intoximeter could not be challenged by such evidence was overruled in Cracknell v Willis.
(42)[1988] AC 450, 468DE.
(43)Ibid, at p 472BC.
(44)At pp 470G471A he summarised these safeguards as follows:
First, specimens of breath have to be analysed by means of a machine. Second, such a machine has to be a device of a type approved by the Secretary of State. Third, as is well known, the relevant approved device has built into it a mechanism by which it tests itself, and prints out the results of such a test on the statement automatically produced by it, each time it analyses a persons specimen of breath. Fourth, a requirement to provide a specimen of breath can only be made at a police station. Fifth, two specimens have to be given, and that with the higher reading has to be disregarded. Sixth, if the specimen with the lower reading contains less than a specified quantity of alcohol, the defendant may ask that it be replaced with a specimen of blood or urine, in which event, if he provides such a specimen, no specimen of breath shall be used. This is a formidable list of protections for the motorist.
(45)See cl 19 of the draft Bill.