Jurisdiction : DISTRICT COURT OF WESTERN AUSTRALIA

Criminal law - Child pornography - Floppy disks seized by police from appellant - Disks not viewed by police for 10 months - Disks left with Computer Crime Section - No evidence of what happened to the disks in Computer Crime Section - When returned from Computer Crime Section disks viewed and found to contain images of child pornography

Evidence - circumstantial evidence - Whether any alternative reasonable or rational hypothesis open

Criminal Appeals Act 2004 (WA), s 30(5)

Evidence Act 1906 (WA), s 31A

1 McLURE JA: The facts and grounds of appeal are contained in the reasons for judgment of Pullin JA. A central issue in the appeal is whether it was open on the evidence for the jury to be satisfied beyond reasonable doubt that pornographic images of children that were present on computer disks in January 2005 were on those same disks when they were seized from the appellant in March 2004, some 10 months earlier. The evidence established that:

1. the appellant had physical custody and control of the disks whilst viewing pornographic images of children on a computer screen at an internet café in Merredin;
2. the disks seized from the appellant by police in March 2004 were the same disks which, when viewed by a police officer in January 2005, contained pornographic images;
3. after the disks were seized in March 2004 they were placed in locked storage in the Merredin police station and some time later transported by a police officer to Perth and handed to a police officer in the Computer Crime Section of the WA Police who signed for their receipt;
4. the Computer Crime Section returned the disks to Merredin police in December 2004.

2 There was no evidence about what happened with the disks when they were in the possession of the Computer Crime Section or about the systems used by the Computer Crime Section to protect the integrity of exhibits.

3 The prosecution had to prove that the appellant was in possession of the pornographic images in March 2004. In order to prove possession, the prosecution had to establish that the appellant knew that the pornographic images were on the disks when they were in his possession in March 2004. It would be sufficient to establish knowledge if the pornographic images were on the disks when the disks were seized by police. The disks must have contained the pornographic images unless they were subsequently placed on the disks whilst they were in the possession of the WA Police.

4 In theory, the subsequent addition of the pornographic images may be intentional or inadvertent. However, it is difficult to conceive how pornographic images could be accidentally placed on the same disks which were seized from the appellant and returned by the Computer Crime Section to Merredin police. I do not regard that as a reasonable possibility. The remaining question is whether the prosecution is required to adduce evidence to negative any reasonable possibility that a person (whether employed by the police or otherwise) deliberately placed the pornographic images on the disks whilst they were in the possession of police.

5 Continuity evidence is ordinarily adduced to eliminate or reduce the possibility of inadvertent error affecting the identity, or the results of testing, of an exhibit. However, such evidence cannot exclude the possibility of deliberate misconduct by persons with access to the material. That is so regardless of the length of time that the exhibit is in possession of the authorities. Moreover, the mere theoretical possibility of deliberate misconduct based in effect on nothing more than opportunity does not prevent a jury from being satisfied of guilt to the requisite standard. Were it otherwise, convictions for offences requiring storage and testing of substances would be exceptional. There was nothing in the evidence in this case to give rise to a suggestion or possibility of deliberate misconduct. Nor were the police officers who gave evidence cross-examined about the possibility of the pornographic images being placed on the disks after they had been seized. A defence no case submission was based on a claim that the prosecution had not proved that the images were on the same disks as those seized from the appellant.

6 In my assessment, it was open to the jury to be satisfied beyond reasonable doubt that the appellant was in possession of the pornographic images in March 2004 in circumstances where: (1) the appellant was viewing child pornography whilst in physical custody of the computer disks; (2) the actual disks seized by police from the appellant were demonstrated to contain child pornography albeit some 10 months after they were seized; and (3) there is no suggestion in the evidence or in the way the appellant conducted its case at trial that the images were placed on the appellant's disks after they were seized by police.

7 I have reached this conclusion without reference to the presumption of continuity or the presumption of regularity. The former is a presumption of fact that simply reflects the inferences available on the proven evidence whilst the latter is a presumption of law: J D Heydon, "Cross on Evidence" (7th Aust ed) [7255] and [7295].

8 The presumption of regularity is to the effect that everything is presumed to be rightly and duly performed until the contrary is shown. As stated by Ipp J in Selby v Pennings (1998) 19 WAR 520 at 531, there are diverging lines of authority as to whether the presumption of regularity applies at all in criminal proceedings. Ipp J considered those authorities and while he did not attempt to reconcile their differences, he preferred the view that the presumption of regularity should be applied carefully in criminal proceedings.

9 The Privy Council in Dillon v The Queen [1982] AC 484 stated that the presumption of regularity does not apply to cure a gap in the evidence required to prove an essential element of the offence. In that case the defendant was charged with escaping lawful custody. Lord Fraser stated (at 487):

"Their Lordships are of opinion that it was essential for the Crown to establish that the arrest and detention were lawful and that the omission to do so was fatal to the conviction of the defendant ... The lawfulness of the detention was a necessary pre-condition for the offence of permitting escape, and it is well established that the courts will not presume the existence of facts which are central to an offence."

10 A majority of the High Court in Day v The Queen [1984] HCA 3; (1984) 153 CLR 475, also a case concerned with the lawfulness of the defendant's detention, noted that the Privy Council in Dillon "affirmed as established principle the proposition that there is no room for presumptions in favour of the Crown to prove the existence of facts which are central to an offence" (at 485). However, the majority in Day, while noting Dillon and the differences of view which had arisen, reserved on the question. Dillon was followed in this Court in Green v The Queen [2001] WASCA 162; (2001) 24 WAR 192. However, see Holland v The Queen [2005] WASCA 140; (2005) 30 WAR 231 at [121] - [122] per Malcolm CJ.

11 The approach of the majority in Cassell v The Queen [2000] HCA 8; (2000) 201 CLR 189 is instructive. The appellant was convicted of perjury for statements made at a hearing before a Commission. The appellant asserted that the Commission was not composed in accordance with the relevant statute. The majority said (at [16] - [17]):

"There was no evidence which cast any doubt upon the regularity of the proceedings in question.

Although counsel for the appellant announced to Judge Downs, at the commencement of the hearing, that he would put the prosecution to 'strict proof of all matters', if the matters to which he was referring included the appointment of Mr Temby and Mr Roden to their respective offices, he did not do so. He

allowed evidence to be given without objection that they were respectively the Commissioner and an Assistant Commissioner. That having occurred, it is too late now to complain that their appointments were not formally proved."

12 In rejecting the appellant's claim, the majority relied on the evidence adduced at trial and the lack of evidence casting any doubt on the regularity of the Commission's proceedings. Kirby J, dissenting, held that the prosecution had to prove the formal appointments and that the presumption of regularity did not apply to fill the evidential gap.

13 The applicability of the presumption of regularity in criminal cases usually arises in situations where the prosecution is required to prove a positive: the validity of a notice in Selby; the lawfulness of detention in Dillon and Day; and the appointment of Commissioners in Cassell. Different considerations may arise where the presumption is applied to prove a negative. However, I reach the conclusion I do without reliance on the presumption of regularity. I would dismiss grounds 1 and 2.

14 I agree with Pullin JA that there is no merit in ground 3. The evidence of pornographic images of children on the computer screen is strongly probative and materially affects the objective probabilities on the issue of possession and thus the guilt of the appellant. Accordingly, the evidence was properly admissible as propensity evidence and a warning was not required: KRM v The Queen [2001] HCA 11; (2001) 206 CLR 221 at 235 per McHugh J; Noto v The State of Western Australia [2006] WASCA 278.

15 I also agree with Pullin JA that the trial Judge erred in his direction as to what the prosecution had to establish to prove possession of the pornographic images. He should have directed the jury of the requirement as to the appellant's knowledge of the pornographic images on the disks. Having regard to the evidence relating to that issue (to which I have referred in discussing grounds 1 and 2), the error was significant and gives rise to a substantial miscarriage of justice. As I have dismissed grounds 1 and 2, I would set aside the conviction and order a re-trial.

16 PULLIN JA: The appellant was convicted in the District Court after a trial before a Judge and jury on an indictment which read that on 2 March 2004 at Merredin he had in his possession child pornography in the form of computer images contrary to s 60(4) of the Censorship Act 1996 (WA) (repealed). (Currently the Classification (Publications, Films and Computer Games) Enforcement Act 1996).

17 The prosecution case was that there were 27 images of naked female children stored on three floppy disks. The three disks were in the appellant's possession on 2 March 2004. As will appear from the evidence referred to below, these images were not downloaded and viewed by the Merredin police at the Merredin Police Station until 10 months later in January 2005. At the beginning of the trial counsel for the appellant made a concession in the following terms:

"We do not contest that the images downloaded by Officer Beard, I think you will hear at the Merredin police station, from the floppy disks that she received - that they did indeed contain images which contravene section 60(4) of the Censorship Act, which of course constitutes this charge. So just so you're in no doubt at all, we are not contesting that part of the prosecution case."

The images "downloaded by Officer Beard" were downloaded in January 2005. The precise terms of that concession are important for reasons that will be apparent later.

18 The uncontradicted prosecution evidence was as follows. A Mr Hawser was the part-owner of an internet café in Merredin. He knew the appellant because the appellant would come into the café three or four times a week and would stay in the café for long periods of time ranging between to two to eight hours at each visit. There were three computer terminals available for public use.

19 On 2 March 2004 Mr Hawser turned the computers on. Mr Hawser's evidence, at ts 26, was as follows:

"When you turned the computers on, what would be on the screen?---Nothing. Just bare Windows - just a normal computer start up.

Would it be whatever was last used the night before?---No."

20 Mr Hawser cleaned up any personal effects remaining on the desks on which the computer terminals were located. He then saw the appellant arrive. The appellant took up his position at a desk on which one of the computer terminals was located. The appellant left the premises for a short time but then returned and stayed for a considerable period of time. Mr Hawser observed the appellant to have a grey floppy disk container with him. Eventually Mr Hawser saw something on the screen which prompted him to call the police.

21 Two police officers arrived. They were Senior Constable Walker and Constable Christine Beard. They saw the appellant seated at the computer terminal. Senior Constable Walker asked the appellant to move away from the computer. Senior Constable Walker's evidence was as follows:

"Did you observe anything on the computer screen?---I did observe some - like a child pornography site along with - a Virgin Airways flight site, I think it was.

Now, can you describe for us as best as you can how those two sites were displayed on the screen?---The majority of it was the Virgin Airways flight, the majority of the screen.

You are holding your hands up with your hands apart. You are indicating, what, across the width of the screen?---Yeah, across the width of the screen and then over - I believe it was the left-hand side, just down the side was a child pornography site.

You are moving your hands up and down and holding your hands a few inches apart. You are indicating like a strip down the side of the screen. Is that what you mean?---That is correct, yes.

When you say 'a child pornography site,' what exactly did you see?---I can't recall exactly what I saw, but I can recall the name of the site ... I can't remember what it was called now. I think it was roughly Lolita, which I know to be a child pornography site because I've dealt with it in the past.

All right then. Just answer yes or no. Was there then a discussion between you and Mr Mowday?---There was.

Did you notice anything near the vicinity of that computer that he had been using?---There was a grey computer disk case, and there was also a disk inside the hard drive of the computer.

Were there any disks inside the grey container?---There was."

22 Senior Constable Walker seized the grey container which was on the desk next to the computer. There were three floppy disks within the container. Constable Beard gave evidence that she observed "child pornography sites" on the computer screen.

23 The container, the three floppy disks in the container, and the hard drive of the computer were removed from the internet café by the two police and taken to the Merredin Police Station. Sergeant Ryan was at the police station and he recorded the receipt of these materials. The grey container containing the three floppy disks was taped up with red evidence tape and signed by Sergeant Ryan in Constable Beard's presence. Sergeant Ryan was also called as a witness. The container and the hard drive were put into a secure store in the Merredin Police Station by Constable Beard. Constable Beard's evidence was as follows (at ts 61):

"I think - did you enter the property into the police computer?---Yes, I put an IR on the system and entered the property.

IR is incident report?---Incident report, yeah.

So you enter that into the police computer and then you are given an incident report number?---Yes.

That comprises six digits of the date, four digits, being the time, and five digits, being your regimental number?---That's correct.

Was the hard drive also taken?---Yes.

Did you - were you then involved in placing that grey container and the floppy disks into the storeroom?---Yes, I was.

What did you do?---I got the keys for the storeroom, went down, unlocked it, because it's always kept locked, and placed it on Constable Walker's shelf.

Were there any other grey floppy disk containers on that shelf?---No."

Constable Beard printed out a "property tag" and placed that document, the container containing the three floppy disks and the computer hard drive into a bag which she placed in the secure store room at the Merredin Police Station.

24 Later Senior Constable Walker transported this box, including the container with the three floppy disks inside, to Perth where he delivered them into the possession of a police officer in the Computer Crime Section of the police department who signed that he received them. Neither the Sergeant, the Senior Constable nor Constable Beard gave evidence that they put the disks into a computer and viewed the contents before they were sent to Perth. There was no evidence about when Senior Constable Walker effected delivery to Perth. There was no evidence about who took delivery at the Computer Crime Section. There was no evidence about the procedures at the Computer Crime Section for handling the container and disks. There was no evidence about who handled them or how they were dealt with at the Computer Crime Section. There was no evidence about what work was performed on the disks at the Computer Crime Section.

25 In December 2004 the container and the disks were returned by the Computer Crime Section to Merredin. At ts 61 to 63 Constable Beard said in her evidence-in-chief:

"At some stage later, in December of 2004, do you recall receiving a case with floppy disks in it from computer crime?---Yes, I do.

...

If you take those disks out, do they have stickers on them?---Yes, they do.

What do those stickers say?---'Merredin police, disk 1,' my signature and regimental [number], 'Disk 2, Merredin police,' my signature and regimental [number], and, 'Disk 3.'

In January of - when you received that back in December of 2004, where did you place - what did you do with that container and those disks?---I placed them back into the property storage room, which is the same one that's always kept locked, but I put it on my shelf because at that time Constable Walker had left.

Did you - were there any other grey plastic containers with floppy disks on your shelf?---No, there weren't.

And then in January of 2005, did you inspect the floppy disks?---Yes.

Is that all three of them?---Yes.

That's the container and the disks that had been located next to the computer Mr Mowday had been seated at?---Yes, that's correct.

Did you then download from those disks 27 images of child pornography?---Yes, I did.

Now, there is also a document in that bag - a typed piece of paper. Can you open that?---This one?

Yes. What is that?---It's a property tag. It's basically when we have property in an information report, it tags it, so it's internal for the police department to know that that property is at the station and that's the - so when I printed it out, it went straight onto that and straight into the storage room.

So on 2 March 2004 you printed out that document you have in your hand?---Yep.

And was that placed inside that container or in the bag with it? Do you recall?---It was placed probably in the bag with it, yep.

And was that when you - and that was in that bag when you put it into that storeroom?---Yes.

in March 2004?---Yes.

All right. When you received that grey container and disks back in December 2004, was that piece of paper still with the bag?---Yes.

Yes, I would seek to tender that piece of paper. It's a property tracing document, your Honour."

26 There was no cross-examination about this evidence save to elicit from Constable Beard that the stickers placed on the three floppy disks were placed there in December 2004. At the hearing of this appeal counsel for the appellant conceded that that was evidence that the three floppy disks were the same disks which had been seized at the internet café on 2 March 2004.

27 The prosecution then closed its case and counsel for the appellant made a submission that there was no case to answer. He submitted that the fact that there was no evidence from the person who had possession of the disks between the time Constable Walker delivered them to the Computer Crime Section of the police department until they were returned to Merredin in December 2004 meant that there was no case to answer. The trial Judge ruled that there was a case to answer. The appellant then elected not to give evidence. The jury returned a verdict of guilty and a conviction was recorded.

"Ground 1:

Having regard to the evidence, the verdict of guilty is unreasonable or can not be supported by the evidence.

1. The State's case was that there was seized in Merredin computer discs [sic] and a hard drive from the Merredin Internet café. These were then transported to the police station, placed in store at the police station and then these items were taken to the Perth Computer Centre where they were left with an unknown person for an unknown length of time and subsequently the items were returned from the Perth Computer Centre to the Merredin Police, they were then examined and 27 images of child pornography located.
2. There was no evidence from any witness as to the continuity of the hard drive and discs [sic] from the time that they were received by the Perth Computer Centre until the time they were returned to the Merredin Police and the images of a child pornography [sic] located.

1. In the absence of such evidence the verdict of guilty is unreasonable and cannot be supported by the evidence because the evidence is not capable of establishing that the images located and viewed by the police officers in January 2005 were images on the discs [sic] which the jury found to be in possession of the Appellant in March 2004.

Ground 2:

The evidence of the State taken at its highest was not capable of establishing beyond reasonable doubt the guilt of the accused.

1. The evidence of the State at its highest was not capable of establishing that the images located and viewed by the police officers in January 2005 were the images on the discs [sic] found by the jury to be in possession of the appellant in March 2004.

Ground 3:

The learned Trial Judge erred in law in his instruction to the jury on the use of propensity evidence.

(a) The Learned Trial Judge failed to adequately warn the jury against reasoning that because they found that the accused had engaged in propensity conduct that he did commit this offence.

Ground 4:

The Learned Trial Judge erred in law in his direction to the jury on "possession" in the circumstances of this case.

(a) The Learned Trial Judge failed to instruct the jury that they must be satisfied beyond reasonable doubt that the accused had control or dominion of the disc [sic] at the time alleged knowing that at the time the disc [sic] contained pornographic images and intended to possess those discs [sic]."

29 The appellant submitted that the jury could not have been satisfied beyond reasonable doubt that the images which were located and viewed by the police officers in January 2005 were images in the possession of the appellant in March 2004 because of the hiatus in the evidence. The appellant points to the lack of direct evidence about what information was on the disks when they were seized. The appellant concedes that the evidence was sufficient to establish that the disks from which Constable Beard downloaded the images in January 2005 were the same disks which were in the appellant's possession on 2 March 2004. However, the appellant submitted that evidence did not prove that the images were on the disks on 2 March 2004 and submitted that the verdict of the jury was unreasonable and could not be supported by the evidence.

30 These grounds rely on s 30 of the Criminal Appeals Act 2004 (WA). There was no dispute that the proper test to be applied in relation to this ground of appeal was set out in M v The Queen [1994] HCA 63; (1994) 181 CLR 487. See also Martinez v The State of Western Australia [2007] WASCA 143 at [4] - [6]. Section 30 and those authorities require this court to make its own independent assessment of the evidence, but to pay full regard to the fact that the jury was the body entrusted with the responsibility of determining guilt or innocence.

31 The charge was possession of child pornography. "Child pornography" was defined in the Censorship Act to mean:

"an article that describes or depicts, in a manner that is likely to cause offence to a reasonable person, a person who is, or who looks like, a child under 16 years of age (whether the person is engaged in sexual activity or not)."

"(b) a film

(c) a computer programme and associated data."

" ... form of recording from which a visual image, including a computer generated image, can be produced ... "

32 The concession which was made at the commencement of trial by counsel for the accused did not amount to a concession that the appellant was in possession of child pornography. It was a concession that the 27 images downloaded by Constable Beard in January 2005 constituted child pornography. It was a concession which should have prompted the prosecutor to lead evidence to support an inference that what was observed to be stored on the disks in January 2005 was what was stored on the disks on 2 March 2004. That required evidence of what happened to the disks in the 10 intervening months.

33 The significant and obvious point is that when Constable Beard and Senior Constable Walker seized the three floppy disks what was on the disks was not visible. The images recorded on the three disks were on the disks when viewed by Constable Beard in January 2005. The issue is whether the 27 images were on the disks when they were seized. There was no direct evidence about this. The police did not put the disks into a computer on 2 March 2004 to see whether there were any images stored on them.

34 If the fact to be proved, namely that the appellant was in possession of the 27 images on 2 March 2004, was to be proved then it had to be proved by circumstantial evidence. Circumstantial evidence is evidence which, if accepted, tends to prove a fact from which the evidence of a fact in issue may be inferred. Festa v The Queen [2001] HCA 72; (2001) 208 CLR 593 at [5]. When considering circumstantial evidence the first task must be to identify the fact in issue which is to be proved by the circumstantial evidence. In this case the fact to be proved was that the 27 images viewed by Constable Beard in January 2005 were resident on the three floppy disks on 2 March 2004. The second task is to identify the evidentiary facts or circumstances which will prove the fact in issue. There appear to be only two evidentiary facts or circumstances. The first was that the appellant was examining pornographic images on the screen of the computer on 2 March 2004. If that was the only circumstance or evidentiary fact then it could not possibly prove that there were images on the three disks because it is possible that the disks may have been blank disks ready to be employed for downloading and storing pornographic images from websites. However, it is not correct to consider circumstantial evidence piecemeal. The effect of all of the available circumstantial evidence must be considered. See R v Hillier [2007] HCA 13; (2007) 81 ALJR 886.

35 The other evidentiary fact or circumstance was that there were 27 images of child pornography on the three floppy disks in January 2005. This evidentiary fact was subsequent to the fact to be inferred. That does not matter. Inferences may be drawn from subsequent circumstances: R v Ciantar [2006] VSCA 263; (2006) 167 A Crim R 504 at [44]; Martinez v The State of Western Australia at [285]. So for example in Taha [2000] NSWCCA 520; (2000) 120 A Crim R 161 a robbery occurred and some hours later a loaded weapon was found in the possession of some of the accused. It was held by Curruthers AJ at [32]:

"In my view, the evidence pointed clearly to the conclusion that the weapon was in fact loaded at the time of the actual robbery. This is a classic case of the application of the principle of the retrospective operation of the presumption of continuance."

36 In Collins v Mithen, unreported; SCt of Vic; 21 May 1975, Gowans J was dealing with an application to review a Magistrate's decision dismissing a charge on the basis of no case to answer. The case involved a charge that the defendant was driving a motor car while the percentage of alcohol in his blood exceeded a prescribed limit. The blood sample which was taken from the defendant was taken by the police to a forensic science laboratory and left there in a locked refrigerated receptacle on 10 May 1974. A certificate of analysis was produced at the hearing stating that an analyst took charge of the sample on 13 May 1974 and analysed it on 30 May. The Magistrate decided that:

"The prosecution has not shown that in the interim period no tampering took place with the sample of blood. There is no firm evidence that proper safekeeping took place or that the sample was sealed against tampering or foreign matter."

Gowans J overturned this decision saying at page 8 - 9:

"On the presumption of regularity it may be assumed that as between 13th May and 30th May the sample in the custody of the analyst was preserved with due regularity.

The matter that raises the difficulty is as to the absence of any direct evidence as to what happened to the container between Friday, May 10th and Monday, May 13th. The suggestion which appealed to the Magistrate was as to the possibility of the contents of the container being tampered with in some way.

But in my opinion there are two presumptions which ought to come into operation in relation to this matter. They are both presumptions of fact. One is a presumption of continuance, that is to say, that it ought to be presumed as a matter of fact that during the short time between Friday evening and the Monday, the blood in the container preserved its identity, that is to say that it continued to be the same blood as was in the container on the Friday night. The same presumption operates to justify an inference that the condition of that blood did not change of itself during that time.

In addition, there is a presumption of regularity in relation to the custody of the sample, or, to put it perhaps in a way which is more pertinent for present purposes, there is a presumption against irregularity with respect to the custody of the sample - a presumption against the occurrence of any fraud against the law.

When these two presumptions are put together, I think the effect that there was evidence that the blood in the container on Friday was the same blood and in the same condition as the blood in the container on the Monday, and that no person had wrongly interfered with the blood itself or with its condition."

Gowans J then concluded that there was a case to answer and remitted the matter for re-hearing.

37 However, there was a different outcome in R v Olejarnik (1994) 33 NSWLR 567 the New South Wales Court of Criminal Appeal was considering a case involving a person driving with more than the prescribed quantity of alcohol in his blood. There was evidence of alcohol in a blood sample taken after the appellant was apprehended. The sample was not taken in accordance with a statutory requirement that the sample be taken within two hours of the time when the police believed that the driving had occurred. The question was whether the presumption of continuance could be applied to hold that the alcohol level in his blood at the time of driving was an infringement of the Act. Curruthers J said at 572 - 573:

"In my respectful view when one is dealing with an element as volatile as changing blood alcohol levels, the presumption of continuance can play no part. It is one thing to say that because Mt Everest was in existence ten years ago this is strong evidence that it exists today ... and another thing to say that because a person's blood alcohol level was 0.110 at 9.40 pm, then it was 0.110 at 7.26 pm.

It is relevant, in this context, to note the statement of principle by Walsh JA in Donoghue v St Luke's Hospital [1969] 2 NSWR 647 at 657 ... . [Where] his Honour said:

'In the circumstances of this case, I think it is unnecessary to refer to the cases concerning the presumption of continuance, or concerning the circumstances in which it may operate retrospectively. In my opinion, these are really no more than a recognition that there are situations in which, by a process of reasoning and inference, a fact may be found to exist at a particular time, without direct proof of its existence then, because of its proved existence at another point of time either earlier or later. But this is of no assistance, unless the facts proved are such that it is legitimate to infer from them the existence of the facts of which direct proof is not available.' "

38 In Mallock v Tabak [1977] VicRp 7; [1977] VR 78 Lush J referred to the presumption of regularity and said at page 84:

"In some situations the law adopts presumption as a means of proof as a matter of policy, but generally speaking, because presumption is a means of proof of fact, the question must almost always arise, and in my opinion it arises in the present case, whether the situation out of which the presumption is said to arise is one which leads to an appropriate degree of mental satisfaction that what ought to have been done was done or that what ought not to have been done was not done."

39 The "presumptions" referred to in Taha, Collins v Mithen, R v Olejarnik, and Mallock v Tabak are "Presumptions" of fact. As the author in Cross on Evidence (7th ed) at [7255] says, "presumptions of fact are not true presumptions. They are merely frequently recurring examples of circumstantial evidence ...". Lush J acknowledged this in Mallock v Tabak (supra) at page 84.

40 What was said by Walsh JA in Donoghue v St Luke's Hospital [1969] 2 NSWR 647 about what inferences it may be "legitimate" to draw from the facts was merely a reflection of what must always be considered in relation to circumstantial evidence; that is, that the fact to be proved should not only be a rational inference to be drawn from the circumstantial evidence but should be the only rational or reasonable inference that could be drawn from those circumstances. See Shepherd v The Queen [1990] HCA 56; (1990) 170 CLR 573 at 578 - 579 per Dawson J; Plomp v The Queen [1963] HCA 44; (1963) 110 CLR 234 at 243 per Dixon CJ.

41 If the only rational or reasonable inference to be drawn establishes the existence of the fact to be proved then this means that there is no alternative reasonable hypothesis or inference which might be drawn and which is consistent with innocence. To be reasonable the alternative hypothesis must possess some degree of acceptability or credibility, and not be fanciful, impossible, incredible, untenable, too remote, or too tenuous; in other words it must be logically possible but also reasonable, not fanciful or chimerical. See Parker v The Queen, unreported; CCA SCt of WA; Library No 960740; 20 December 1996 per Malcolm CJ at 20 where the authorities on the subject are gathered together.

42 Thus the prosecution had to prove that when considered together the two pieces of circumstantial evidence left open only one rational or reasonable inference, namely that the 27 images viewed on January 2005 were on the three floppy disks on 2 March 2004. The difficulty the prosecution faced in sustaining that contention was that floppy disks are a copying medium. They were and are used (although less so nowadays) as a medium for copying information from one computer to be stored for later viewing or use on the same computer or on another computer.

43 The three floppy disks were submitted to the Computer Crime Section. The jury was told nothing about what happened at the Computer Crime Section but by its name it may be reasonably hypothesised that it was a section of the police department where police officers in among other duties examined images of child pornography in relation to other cases and where it may have been necessary to copy images onto floppy disks for a variety of reasons. It may be reasonably hypothesised that in 2004 the police department still used floppy disks. The system in the Computer Crime Section may have prevented images from other cases being mistakenly downloaded and copied on to the three floppy disks which were exhibited in this case, but on the other hand it may not have done so.

44 The inference which the respondent asked the jury and this Court to draw, is that if the images were on the disks in January 2005 then they were there 10 months earlier. The appellant however suggests that a reasonable alternative hypothesis is that the disks did not contain the images on 2 March 2004, which must mean that some mistake, mishap or tampering occurred when the disks were at the Computer Crime Section. The question then is whether this alternative hypothesis is fanciful, impossible, incredible or untenable. The conduct of the prosecutor at trial suggested that the alternative hypothesis was not fanciful, impossible, incredible or untenable. This was the conduct of the prosecutor in eliciting evidence (commonly called continuity evidence) about precisely what happened to the disks in the Merredin Police Station. The fact that the prosecutor led as much continuity evidence as he was able to do through the three witnesses available to him suggests that the prosecutor wanted to prevent the advancement of any hypothesis that there might have been some mishap, mistake or tampering which might have resulted in the pornographic images being copied on to the disks when they were in the custody of the police. However, no evidence was led about what happened to the disks in Perth while at the Computer Crime Section. Presumably they were sent there for something to be done to them.

45 Continuity evidence is often perceived to be, and often is, a waste of time. It is usually sensible for a prosecutor to enquire of legal representatives for an accused about whether continuity evidence has to be led or whether a concession will be made to avoid time being taken up at trial with that evidence. Alternatively the issue should be explored in a pre-trial directions hearing. If no concession is made the prosecution knows that it might have to prove what happened to the object under consideration. The nature of the object will determine what continuity evidence has to be led. Continuity evidence may sometimes be necessary because there is a genuine question about the authenticity of a sample or object, the movement of which must be traced, to be certain that it has not been contaminated or altered in any way in the period between the moment of seizure through to the time when it is produced and identified in court or through to the time it was subject to analysis or inspection. This issue is more likely to arise when samples or objects are easily contaminated or easily alterable. The content of floppy disks is easily, mistakenly or deliberately alterable. Images stored on floppy disks are in that sense, ephemeral.

46 In the absence of evidence about what happened to the disks in the Computer Crime Section and in the absence of any evidence at all about the systems in the Computer Crime Section it was simply not possible to be satisfied beyond reasonable doubt that the images viewed by Constable Beard in January 2005 were images which resided on the disks on 2 March 2004. This was because the inference the prosecution wanted to be drawn from the circumstances was not the only rational or reasonable inference which could be drawn.

47 It was not open to the jury to be satisfied beyond reasonable doubt that the accused was guilty. The verdict is therefore unreasonable and cannot be supported having regard to the evidence. As a result grounds 1 and 2 must be upheld.

48 By this ground the appellant contends that the trial Judge erred when he instructed the jury:

"Now, there was mention made of the images which were seen by police officers on the screen at the computer site ... That evidence cannot be used by you to think that Mr Mowday is the type of person who would commit this offence. This would involve a process of reasoning which would be quite wrong because you would be reasoning on your assessment of Mr Mowday's character or propensity rather than on the basis of the relevant evidence. Your duty is to decide each charge on the basis of the relevant evidence."

49 The appellant in his written submission refers to Donaldson v The State of Western Australia [2005] WASCA 196; (2005) 31 WAR 122 and the fact that Roberts-Smith JA at [118], [125] and [129] said that propensity evidence under s 31A of the Evidence Act 1906 (WA) was admissible because it shows the propensity of an accused to commit offences of the kind charged. The appellant continued however by submitting that it was nevertheless necessary to give a warning about reasoning of that kind.

50 This submission must be rejected. The evidence about what was seen on the screen was circumstantial evidence relevant both to the question about whether or not the images viewed by Constable Beard in January 2005 were on the disks on 2 March 2004, but also, and, more importantly, relevant to the issue of possession. If it had been established that the 27 pornographic images resided on the disks on 2 March 2004, then the fact that the appellant was viewing child pornography on the screen of the computer was a relevant circumstance in deciding whether the appellant knew that he had possession of the pornographic images on the three floppy disks.

51 There was no need for the trial Judge to give any warning (but in any event he did so). Ground 3 must be dismissed.

52 The appellant complains about the direction given by the trial Judge concerning the element of possession.

"The second element of the offence is the element of possession and this is the one that you have heard the most evidence about and about which you heard the submissions from counsel. You have heard the defence concede that the discs [sic] contain child pornography. You can therefore be satisfied beyond reasonable doubt that the discs [sic] did contain pornography and I direct that you should find that. However, possession remains an issue and you must decide whether Mr Mowday did have possession, and going with that question is whether the discs [sic] that were seized were the same discs [sic] as those which were tested by Constable Beard. As with all elements of the offence, the state must establish possession beyond reasonable doubt. Possession in this context is having something, knowing that you have got it, and intending to exercise some control over it. A dictionary would tell you that to possess something means to have the thing."

"In the end, you must be satisfied beyond reasonable doubt the floppy disks which were examined by Constable Beard and found to contain pornographic images were the same disks as were removed from the Internet cafe on 2 March 2004. There are two questions in relation to the disks; firstly, possession; secondly, are they the same ones?"

54 What the jury had to be satisfied about in relation to possession was that the appellant had possession of the 27 pornographic images knowing or suspecting that the images were stored on the disks. As to knowledge see The State of Western Australia v "R" [2007] WASCA 42.

55 The respondent conceded that the learned trial Judge erred in his direction on the concept of possession by erroneously applying the element of knowledge to the floppy disks per se as opposed to focusing on the element of knowledge on the contents of the floppy disks.

56 The respondent's concession was properly made and ground 4 must be upheld.

Is there a substantial miscarriage of justice

57 If the only error had been in relation to ground 4 then it would have been an appropriate case to give consideration to whether, notwithstanding that miscarriage, there was no substantial miscarriage of justice. In Darkan v The Queen [2006] HCA 34; (2006) 80 ALJR 1250 there was an erroneous direction concerning the meaning of "probable consequence" in a case of murder where the appellant was said to have had a common intention to prosecute an unlawful purpose. Notwithstanding that miscarriage the High Court concluded, on a review of all of the evidence, that there had been no substantial miscarriage of justice.

58 However, it is not possible in view of the deficiency of evidence referred to in relation to grounds 1 and 2, to reach a conclusion that there had been no substantial miscarriage of justice. This is because there is an absence of critical evidence that the appellant was in possession of the images on 2 March 2004.

Should there be a new trial or a verdict of acquittal

59 Section 30(5) of the Criminal Appeals Act 2004 (WA) provides that if the Court of Appeal allows the appeal it must set aside the conviction of the offence and must order a new trial or enter a judgment of acquittal. There is High Court authority bearing on the decision about whether a new trial should be ordered or whether there should be a judgment of acquittal.

60 In King v The Queen [1986] HCA 59; (1986) 161 CLR 423 at 433 Dawson J said that it was well established that the discretion to order a new trial should not be exercised, when the evidence in the court below was not sufficiently cogent to justify a conviction or, to allow the Crown to supplement a case which has proved to be defective. In short, the prosecution should not be given an opportunity to make a new case which was not made at the first trial. See also Murphy J in King v The Queen at 427 and R v Wilkes [1948] HCA 22; (1948) 77 CLR 511 at 518. In R v Taufahema [2007] HCA 11; (2007) 81 ALJR 800 at [63] Gummow, Hayne, Heydon and Crennan JJ in a joint judgment affirmed the proposition that where a criminal appeal succeeds on the ground that the evidence of the trial is insufficient to justify a conviction, it is against principle to order a new trial.

61 It was revealed by the respondent in this case that if there were a new trial the prosecution would seek to lead evidence concerning the handling of the disks in the Computer Crime Section. Affidavits were filed which revealed that this would trace the disks from the Merredin Police Station in to and out of the Computer Crime Section back to the Merredin Police Station. The evidence is of course untested by any cross-examination but the question is whether the prosecution should be allowed the opportunity to attempt to repair the defect in proof on a second trial. High Court authority makes it clear that will not be permitted. In Parker v The Queen [1997] HCA 15; (1997) 186 CLR 494 at 519 Dawson, Toohey and McHugh JJ said when hearing an appeal in a criminal case:

"... it is apparent that on a re-trial the appellant would be called upon to meet a quite different case to that presented against him at trial. That would be unfair ... "

62 In R v Taufahema (supra) Kirby J pointed out (at [168]) that a consequence of the common law system of criminal procedure was that accused persons are ordinarily bound by the conduct of their legal representatives. His Honour referred to the reluctance of courts of criminal appeal to permit an accused having second thoughts on appeal to challenge miscarriages of justice said to have arisen from tactical

decisions made by trial counsel in the course of trial. His Honour continued (at [168] - [169]:

"This reluctance has a very practical foundation. Such decisions are made in trials on countless occasions every day. If they were susceptible to being reopened on appeal, few forensic choices could be treated as final. Trials, and appeals, might never conclude. For this reason, in very many cases, this court has declined to permit accused persons to re-open decisions made by counsel at trial characterised as those made for tactical reasons.

There is no reason of principle why the same rule, holding the accused to the tactical decisions of legal representatives, should not apply with equal force to tactical decisions made at trial by prosecuting counsel. Indeed, because defence counsel more frequently have less experience, expertise and resources, any principle of equality would require that the rule holding a party to the tactical choices made by trial representatives should apply with even greater rigour in the case of a prosecutor." (Footnotes omitted).

63 The decision made by the prosecutor not to lead continuity evidence about what happened to the three floppy disks in the Computer Crime Section and their journey back to the Merredin Police Station may or may not have been tactical. Counsel for the prosecution might not have realised that there was a significant gap in the evidence. Alternatively, the prosecutor may have realised that there was a gap, made enquiry and been wrongly informed that there was no continuity evidence to fill the gap. Another alternative is that he simply pressed on, knowing of the gap. Whatever the reason the prosecution cannot be given a second opportunity to prove what it did not prove in the first case.

64 As a result the conviction must be set aside, the verdicts quashed and there must be a judgment of acquittal entered.