Friday, 11 December 2009

Are computer hard-drive contents a 'document'?

On 8 December 2009 the Supreme Court decided DPP v Chao [2009] VSC 562.

Mr Chao was accused of possessing child pornography found on a computer hard-disk-drive (HDD) he left with a computer repairer. (Possession wasn't argued in this appeal, but it's settled law that the offence requires knowing possession: Police v Kennedy (1998) 71 SASR 175; R v Land [1999] QB 65 at 69 – 71.)

The police relied on evidence from a police officer (who since left the police force) who had examined the HDD and its contents.

Mr Chao's barrister objected to evidence of the contents of the HDD.

[7] At this stage of the proceedings senior counsel for the respondent indicated that he objected to any further evidence being given in that context “...because any information that Mr Knott has derived has been derived from the computer and, unless certain prerequisites are satisfied, what he reads from the computer and information he derives from the computer is inadmissible.” He then referred the Magistrate to s 55B of the Evidence Act (1958) identifying the requirements and submitting that what is read from a computer is not admissible unless the pre-conditions are satisfied or by the prosecution being able to “satisfy various common law requirements”.

Section 55B of the Evidence Act 1958 relevantly provides:

55B. Admissibility of statements produced by computers

(1) In any legal proceeding where direct oral evidence of a fact would be admissible, any statement contained in a document produced by a computer and tending to establish that fact shall be admissible as evidence of that fact, if it is shown that the conditions mentioned in subsection (2) are satisfied in relation to the statement and computer in question.

(2) The said conditions are—
(a) that the document containing the statement was produced by the computer during a period over which the computer was used regularly to store or process information for the purposes of any activities regularly carried on over that period, whether for profit or not, by any person;

(b) that over that period there was regularly supplied to the computer in the ordinary course of those activities information of the kind contained in the statement or of the kind from which the information so contained is derived;

(c) that throughout the material part of that period the computer was operating properly or, if not, that any respect in which it was not operating properly or was out of operation during that part of that period was not such as to affect the production of the document or the accuracy of its contents; and

(d) that the information contained in the statement reproduces or is derived from information supplied to the computer in the ordinary course of those activities.

Ultimately, Lasry J accepted that s 55B applied to the evidence the prosecution wanted to adduce, and decided the magistrate was correct to exclude it.

Section 55B is in Part III, Division 3 of the Evidence Act 1958. Part III, Div 3 will be repealed with effect from 1 January 2010 by s 15 of the Statute Law Amendment (Evidence Consequential Provisions) Act 2009.

When it goes, the 'equivalent' provisions in the Evidence Act 2008 will be ss 48, 146 and 147. (In appropriate cases, s 161 — discussed in my post here — will also apply.)

Because those provisions are different in their purpose, I suspect the effect of DPP v Chao will be fairly short-lived.

In any event, on my reading of the case, I think the argument in Chao incorrectly categorised the evidence and the Court made the wrong decision.

Section 55B applies to documents — which can encompass HDD-contents, by virtue of the definition in s 3 — when they are to be tendered in evidence in place of oral evidence. Note the opening words of sub-section (1): "In any legal proceeding where direct oral evidence of a fact would be admissible..."

The effect of s 55B is to exclude documents from evidence, in place of oral evidence on the point to be proved, unless the prescribed criteria are met.

It says nothing about evidence of the content of a document, or about the direct oral evidence of the facts that might also be produced by computer and contained in that document. To argue that the oral evidence was inadmissible because the the document was, was to put the cart before the horse.

But, because these provisions are about to be repealed, it won't matter much in about 21 days.

addendum A few weeks ago lawyer Peter Black wrote an interesting article on his blog, E-courts only work with e-judges and e-lawyers. I think some of his points there might have applied in this case.


Jeremy Gans said...

I agree that this case is bodgy, but disagree with your analysis.

The short of the problem is that s55B is a hearsay exception, and the evidence in question doesn't need to fall within it (or any other hearsay exception) because it isn't hearsay.

The long of it:

Section 55B doesn't exclude anything. Rather, it is an inclusionary rule, overriding any other rules of evidence that might otherwise exclude a document. It only does this for documents containing a fact where (a) oral evidence of the fact would be admissible; (b) other conditions about the document are satisfied (i.e. that it is stored on a computer that regularly records human activities.) In other words, s55B overrides the hearsay rule (with governs people-generated facts) for facts contained in some computer-stored documents. If you look at s55 - the business records exception - you'll see that it's in the same form.

Section 55B is actually an awesomely stupid provision and it's great that it has less than three weeks to live. It is premised on the idea that hearsay statements somehow become more reliable - so reliable that the hearsay rule can be dispensed with - just because they are stored on a computer that regularly records human activities. It is based on a UK provision drafted in the 1960s - when computers were the size of rooms and programmed by flash cards - and has been unchanged since then. Perhaps 1960s computers were so difficult to build and program that it was safe to presume that they would only contain correct facts. But that's obviously not true now, see e.g. the internet. Section 55B is now so ridiculous that most contemporary Victorian lawyers wrongly assume that it isn't a hearsay exception at all, but instead some sort of exclusionary rule for certain sorts of documents.

And that's what seems to have happened in this case (although the summary of facts is so unclear that it's hard to be sure.) The problem here, though, is that, while the documents are computer-stored, the facts in them are almost certainly computer- (NOT people-)generated. The registry records on the hard drive are automatically generated whenever the hard drive is connected to a computer or (possibly) a file is opened. So the registry records are NOT previous representations by people, so they aren't excluded by the hearsay rule. Just like surveillance camera pictures of goods at a warehouse - or blood-stains on a piece of paper - aren't excluded by the hearsay rule (to prove, e.g. that the goods were at the warehouse or that the paper was at the scene of a violent event.) In Lasry's defence, it seems that this point wasn't fully appreciated at the magistrates court. But, sadly, I don't think he fully appreciated it either.

The good news with the UEL is that it is much clearer in both describing the limits of the hearsay rule and in flagging exceptions to the rule.

Anonymous said...

I have heard about a controversy at the moment (not quite the same as this but anyway) about section 86 of the new Evidence Act.

The way I read the section is it just means that statements cannot be tendered against an accused unless they have signed it as an accurate statement.

I have heard it said that this means that the evidence of a conversation with an accused will not be able to be used unless the accused has signed a statement about it.

This does not sound right to me. Am I right?

Jeremy Gans said...

Yes, anonymous, it doesn't sound right. Section 86 is a ban on certain written documents (i.e. ones that are written by cops, contain admissions and are unsigned.)

But it doesn't ban: (a) documents written by the accused; (b) oral evidence from cops (or anyone else) about what the accused said to the cops; (c) using the unsigned document to refresh the cop's memory; (d) electronic recordings of what someone said to the cops; (e) documents signed by the accused.

In light of (relatively) modern rules requiring electronic recordings for many admissions, s86 only matters if both (a) an exception to the recording rule applies; and (b) the cop's oral evidence isn't enough (e.g. because the cop's dead, or because the cop is unconvincing.)

Jeremy Gans said...

Further to my comment on s55B, see Lord Hoffman's discussion at [1999] HKCFA 8, [50]-[55] on HK's similar provision. The case concerned bodgy (computerised?) book-keeping, where the books were being relied on as evidence of fraud.

"50. That brings me to the second certified question, which concerns s.22A. This is a remarkable provision. It lays down the conditions upon which a statement contained in a document produced by a computer must be admitted as prima facie evidence of any fact so stated. In some respects these conditions resemble s.69 of the English Act of 1984 and in others they are more restrictive. For example, the computer must have been used for the purpose of activities carried on by any body or individual and the statement produced by the computer must be derived from information supplied in the course of those activities: subsection 2(a) and (b). Subsection (c) requires evidence that the computer was working properly. But, unlike s.22, the section contains no requirement that the person who supplied the information had, or might reasonably be supposed to have had, personal knowledge of the facts. I do not understand the rationale for this distinction. The fact that a statement was generated by a computer is no guarantee whatever of its accuracy. If wrong information was fed into the computer, wrong information will come out. It is true that there was also no such requirement in s.69 of the Act of 1984. But s.69 was an additional requirement which had to be satisfied by statements produced by computers, as well as any conditions which might have to be satisfied to come within an exception to the hearsay rule: see R. v. Shephard [1993] A.C. 380. Section 22A, on the other hand, is an independent exception."

51. I can, however, leave these matters for consideration in due course by the legislature because it is accepted that the computer-generated documents in this case did not satisfy the conditions of s.22A....

55. Section 22A(11), however, says that nothing in the section is to affect the admissibility of a document produced by a computer where it is tendered "otherwise than for the purpose of proving a fact stated in it." For the reasons which I have already explained, I do not think that the documents were being used for the purpose of proving any fact which they contained and s.22A therefore did not affect their admissibility."

Note that our s55B lacks an equivalent to HK's s22A(11), but I don't think that changes anything (though it's inclusion would presumably have alerted Lasry J to the error he was making.)

Elucubrator said...

Jeremy, interesting points you make.

I think we might be both saying much the same thing, just in different ways.

The case seems to have assumed that the witness was to give evidence of the contents of a document — in this case, a HDD — in much the same way a witness might try to say, "I read the letter, and the letter said..."

I don't agree with that analysis. I agree with you, that the evidence should properly be categorised as direct evidence. (At least, that's what I think, and I think that I'm agreeing with you!)

The problem is that the 1958 Evidence Act is just so far behind the times concerning technology that it doesn't even begin to really address these issues. To think of a HDD as a 'document' to be 'read', rather than something that can be perceived — albeit requiring a computer and monitor to do that — is similar to saying a digital photograph of a scene, authenticated by a witness who previously saw scene, is inadmissible unless the the 'computer' (camera) operated in accordance with s 55B(2).

It just misses the relevance and nature of the evidence completely.

I hope the new Evidence Act succeeds in its aims of bypassing these sorts of issues.

Thanks for the info about the HK case. There's some surprisingly useful judgments from there!

Jeremy Gans said...

Yes, just different ways of making the same points. (That's all I meant by disagreeing with your analysis.)

The UEL will indeed help. The drafters of s55B had the problem that they were creating an exception to an unwritten and almost unwritable common law rule, while the drafters of the UEL don't have that problem.

But I really wish the UEL had framed its exclusionary rules around 'uses' of evidence, rather than 'admissibility'. As a gazillion evidence lawyers and judges have said before me, there's no understanding evidence law unless you think primarily about how any item of evidence is used...