Computer Generated Evidence in Court

Computer Generated Evidence in Court

Introduction

We are living in what is usually described as an 'information society' and as

the business community makes ever greater use of computers the courts are going

to find that increasingly the disputes before them turn on evidence which has at

some stage passed through or been processed by a computer. In order to keep in

step with this practice it is vital that the courts are able to take account of

such evidence. As the Criminal Law Revision Committee recognised, 'the

increasing use of computers by the Post Office, local authorities, banks and

business firms to store information will make it more difficult to prove certain

matters such as cheque card frauds, unless it is possible for this to be done

from computers' (CLRC 1972, para 259).

Admissibility

The law of evidence is concerned with the means of proving the facts which are

in issue and this necessarily involves the adduction of evidence which is then

presented to the court. The law admits evidence only if it complies with the

rules governing admissibility. Computer output is only admissible in evidence

where special conditions are satisfied. These conditions are set out in detail

in section 69 of the Police and Criminal Evidence Act (PACE) 1984 (see further

Nyssens 1993, Reed 1993 and Tapper 1993).

In general the principles of admissibility are that the evidence must be

relevant to the proof of a fact in issue, to the credibility of a witness or to

the reliability of other evidence, and the evidence must not be inadmissible by

virtue of some particular rule of law (Keane 1994, pp 15-20; Tapper 1990, pp 51-

61).

Real evidence usually takes the form of some material object (including computer

output) produced for inspection in order that the court may draw an inference

from its own observation as to the existence, condition or value of the object

in question. Although real evidence may be extremely valuable as a means of

proof, little if any weight attaches to it unless accompanied by testimony which

identifies the object in question and explains its connection with, or

significance in relation to, the facts in issue or relevant to the issue.

This is illustrated in the case of R v Wood (1982) 76 Cr App R 23 where the

appellant was convicted of handling stolen metals. In order to prove that metal

found in his possession and metal retained from the stolen consignment had the

same chemical composition cross-checking was undertaken and the figures produced

were subjected to a laborious mathematical process in order that the percentage