Computer Generated Evidence in Court

Computer Generated Evidence in Court :


The McKeown case also gives rise for concern in that the defence raised the smoke-screen of concentrating on the fallibility of the computer evidence rather than the reliability of such evidence. This point was raised by Dr Castell when he delivered The VERDICT Report to the Treasury in 1987.


He was perturbed that the current law could be effectively exploited by defence counsel to undermine a prosecution. The Law Commission in its Consultation Paper (Law Com CP No 138) claims that there is support for this contention in that judges commented on the lengthy cross-examination of prosecutions' computer experts. It will be recalled that the standard of proof in a criminal case for evidence tendered by the prosecution is beyond all reasonable doubt. The intricacy and complexity of many modern computer systems may make it relatively easy to establish a reasonable doubt in the juror's mind as to proper functioning of the computer. Using the example of the McKeown case it appears that in the absence of a presumption that the computer is working means that it may be quite easy to raise such a smoke screen. It would seem perfectly feasible that where there are doubts as to the reliability of computer generated evidence these doubts should not go to the issue of admissibility but rather to the weight of the evidence. As we have seen in Shepherd s 69 only applies where computer generated documents are tendered in evidence and there is an affirmative duty on those introducing computer evidence to show that at all times it is safe to rely on it. Thus when applying a literal interpretation of the statutory provision illogicality and confusion reigns as demonstrated by the McKeown case. Furthermore it has been held that s 69 does not apply where a witness uses computer generated evidence to refresh his or memory or where it is used by an expert to reach a conclusion. In Sophocleous v Ringer [1988] RTR 52, another driving with excess alcohol case, evidence was given against the accused by an analyst who had used a computer which produced a graph illustrating the levels of alcohol in the blood stream. The graph was not put in evidence but the analyst was allowed to look at it to refresh her memory. As the graph had not been put in evidence the court held that s 69 did not apply.


The same outcome is illustrated in a recent Court of Appeal case, R v Golizadeh [1995] Crime LR 232. In this case a brown substance was found in the possession of the appellant which turned out to be a Class A drug (opium). The substance was analyzed through a machine which produces a print out in the form of a pattern.


This pattern is then interpreted by an expert to determine the chemical constituents of the substance. In arriving at his conclusion that the substance was indeed opium the expert witness relied on his own interpretation of the print out and the opinion of another expert called to give evidence. One ground of appeal was that under s 69 PACE the evidence should have been excluded on the basis that it was based on the computer print outs and was therefore inadmissible. The Court of Appeal rejected this argument and held that s 69 did not apply. Morland J reiterated Lord Griffith's speech in the Shepherd case whereby he stated that the object of s 69 requires anyone who wishes to introduce computer evidence to produce evidence that will establish that it is safe to rely on the documents produced by the computer. Thus it is clearly the case that s 69 will only apply where computer print outs are actually put in evidence. Since in the present case the print outs had merely been used by the experts in reaching their findings as to the chemical constituents of the substance s 69 had no application on the facts of the case. In the words of the Law Commission in its recent Consultation Paper 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. The irony of the situation is that it appears perfectly acceptable for evidence to be adduced which is based on computer generated print outs but at the same time if the computer evidence itself was to be presented to the court then the hurdle of complying with s 69 would have to be surmounted. Are the special provisions necessary?


As we have seen, the statutory provisions impose special conditions on the admissibility of computer output. Are these justified? What is it that is special about computer-generated documents and that distinguishes them from their paper equivalents? It is obvious from examination of the admissibility requirements that computer evidence is regarded as suspicious in several respects the main problem is concerned with the authentication and accuracy of computer records. It is almost as if the technology is believed to be inherently inaccurate.


Section 69 PACE requires some minimum proof of accuracy before the document is admissible. The court must be satisfied of the reliability of the statement as a true record of what the witness observed and also of its authenticity as an accurate record of what was intended to be recorded. As a result it is necessary to show tat at all material times the computer had been functioning properly or at least that any malfunction had not affected the accuracy of the information.


It was envisaged by the Criminal Law Revision Committee (CLRC 1972, para 259) that there would be many cases where the document might have become corrupted by software errors or hardware malfunctions. It is the contention of this article that this suspicion was probably unfounded on the basis that there has been has been no tangible evidence to date illustrating why computer records are likely to be less accurate than those contained on paper. Paper based records are also susceptible to alteration and deterioration yet where it is alleged that such alteration has taken place, the paper document remains admissible and the challenge goes to the question of its weight as evidence, to be decided on the basis of the evidence called to prove falsification or authentication. Regarding documentary evidence para 3 of Schedule 2 to the Criminal Justice Act 1988 provides that in estimating the weight, if any, to be attached to ... a statement [given in evidence under section 23 or section 24] regard shall be had to all the circumstances from which any inference can reasonably be drawn as to its accuracy or otherwise.


Although no particular circumstances are specified, it seems safe to assume that regard may be had, for example, to the following matters whether the person who made the statement in a document did so contemporaneously with the occurrence or existence of the facts dealt with in the statement whether any person who supplied the information did so contemporaneously with the occurrence or existence of the facts dealt with in that information and whether or not such persons or the creator of the document containing the information had any incentive to conceal or misrepresent the facts. In stark contrast to this, unless it can be shown that there is no chance of unauthorized use of a computer system, or of system failure, the same document stored on computer is inadmissible under the additional requirements of section 69 PACE. Doubts concerning the accuracy of information recorded on computers apply equally to paper-based systems, as do those concerning authentication. As with paper records, the necessary degree of authentication can be proved through oral and circumstantial evidence, if available or via technological features of the system or record.


Computer Generated Evidence in Court - Computer Generated Evidence in Court - Computer Generated Evidence in Court - Computer Generated Evidence in Court - Computer Generated Evidence in Court - Computer Generated Evidence in Court - Computer Generated Evidence in Court - Computer Generated Evidence in Court





1 | 2 | 3


More Essays on Law and Management

Computer Generated Evidence in Court :

Essays Index


Computer Generated Evidence in Court To HOME PAGE