5.29 An example of records comprising a mix of human input and calculations generated by software is that of a financial spreadsheet program that contains
human statements (input to the spreadsheet program), and computer processing (mathematical calculations performed by the spreadsheet program). From an evidential point of view, the issue is whether the person or the software created the content of the record, and how much of the content was created by the software and how much by the human. It is possible that the quality of the software acts to undermine the authenticity of the data, which may in turn affect the truth of the statement tendered in evidence.
The algorithms in spreadsheet programs are a good example of where the software code affects the truth of the statement. For a more detailed analysis, see the chapter on authentication.
5.30 Professor Pattenden suggests that ‘most representations of fact require human intervention at some point’,1 which must be right. The Law Commission report also indicated:
By contrast, the law does sometimes exclude evidence of a statement generated by a machine, where the statement is based on information fed into the machine by a human being. In such a case, it seems, the statement by the machine is admissible only if the facts on which it is based are themselves proved.2
1 Pattenden, ‘Machinespeak’ 623, 633.
2 Law Commission, Evidence in Criminal Proceedings: Hearsay and Related Topics para 7.46.
5.31 This comment distinguishes between information fed into a machine (the word ‘computer’ is not used, but the word ‘machine’ is presumably meant to include a computer or computer-like device), and the instructions contained in software code written by human beings that are essential for a device to work. Where a person inputs information into a computer, and that information is to be relied upon as to the truth of the statement, then the person should give oral evidence of this action. In contrast, the software code that might be used to transform the raw data into information that can be used is not necessarily relevant, depending on the purpose for which it is adduced in evidence. To this end, the Law Commission1 compared the cases of R vWood (Stanley William)2 and R v Coventry Justices, Ex p Bullard.3 In Wood, the evidence of the analysis by a computer of tests carried out by chemists was not considered to be hearsay because the chemists gave oral evidence of the results of the tests. The calculations performed by the computer were carried out under the instructions of the person who wrote the software code. The chemists were able to give oral evidence of the results of the tests they performed, but the computer software carried out the actual analysis.
The calculations relied upon the software code, which was created by a human being (in this case, a Mr Kellie). The software analysed the data in accordance with the instructions given to it by Mr Kellie. The computer was not capable of analysing the data without the software code. The chemists gave oral evidence of the results of the computer program. This means that the truth of the content of the output of the computer was predicated upon the software code created by Mr Kellie.
1 Law Commission, Evidence in Criminal Proceedings: Hearsay and Related Topics, para 7.47.
2 (1983) 76 Cr App R 23 (CA), J C Smith [1982] Crim LR 667 (note).
3 (1992) 95 Cr App R 175 (QB), [1992] RA 79; ‘Print-out inadmissible as hearsay’ (1993) 57 JCL 232.
5.32 In comparison, the computer print-out in R v Coventry Justices, Ex p Bullard included a statement that a person was in arrears with his community charge. This was held to be inadmissible hearsay because the content of the print-out contained information that had been put into the computer by a human, and the print-out had not
been properly proved. The Law Commission, agreeing with the result, would propose a similar analysis as follows:
An alternative view is that the statement by the machine, properly understood, is conditional on the accuracy of the data on which it is based; and that, if those data are not proved to have been accurate, the statement therefore has no probative value at all. The question of hearsay does not arise, because the statement is simply irrelevant.1
1 Law Commission, Evidence in Criminal Proceedings: Hearsay and Related Topics, para 7.48.
5.33 In Mehesz v Redman,1 Zelling J concluded that the output of an auto-lab data analyser was hearsay, given that the analysis relied on software where the writer of the software had not been called, and where modifications had been made but the person responsible for the modifications had not been called either. A similar decision was made in Holt v Auckland City Council,2 where evidence of the analysis of the amount of alcohol in a blood sample was excluded by the New Zealand Court of Appeal because the truth of the statement tendered was predicated upon the software code written by a programmer who was not called to give evidence, which meant there was a gap in the continuity of proof. In contrast, in Wood, the oral evidence of the results of the tests were read out by the chemists from print-outs of the computer (which was real evidence), and if the results were to be challenged for their accuracy, then the integrity of the software program might need to be tested.
1 (1979) 21 SASR 569.
2 [1980] 2 NZLR 124.
5.34 The instructions written by a human in the form of software code can, depending on the circumstances, be just that: instructions to the machine to perform a particular task. This is illustrated in the case of Maynard.1 An item of software, called a trace, had been written to ascertain whether a particular employee was obtaining access to private information in a computer system, and if so, to record the time and date that the employee viewed the data. The employee was subsequently prosecuted.
The magistrate refused to admit the evidence of the print-out of the trace data, partly because he considered the record of the time and date to be hearsay. On appeal, Wright J rejected this analysis. The person that wrote the code gave evidence at trial, both as to the reason for writing the code and as to how it worked. The judge indicated that:
… it seems to me that once the trace was applied to the respondent’s log-on identification, the process then undertaken by the trace was entirely mechanical in that the peregrinations through the database by that computer user was automatically traced through the system and were recorded and stored ready for retrieval in report form as soon as the trace print-out was called for.2
1 (1993) 70 A Crim R 133, sub nom Rook v Maynard (1993) 126 ALR 150.
2 (1993) 70 A Crim R 133, 141.
5.35 Wright J then went on to illustrate the separate steps:
Although much more complex in its operation than the following description suggests, the process, stripped to its essentials, involved (a) The implementation of the trace program and its attachment to the respondent’s log-on identification.
This was a human function proved by direct evidence from Mr Poulter [the person who wrote the code]. (b) Once attached, the trace followed the log-on
identification number and the user and (c) when the user tapped into or called up a particular file from the database, the trace was able to store details of this event in its memory for subsequent retrieval.
5.36 There was no evidence that suggested that the trace program modified any other programs in the computer, and if there were any such failings, the program designer could have been cross-examined on them. For this reason, the statement was not hearsay.