SUPREME COURT OF QUEENSLAND

1. THE COURT:  On 13 February this year the appellant was convicted of murdering Celia Natasha Douty probably on 1 September 1983.  He appeals against that conviction on two grounds.  The first is that the verdict was unsafe and unsatisfactory.  The second is that the learned trial judge erred in failing to uphold the submission that there was no case to answer.

2. Ms Douty was murdered when she was apparently sunbaking on a beach at Brampton Island. Her body was discovered in some undergrowth in a place called Dinghy Bay, unclothed but covered with a red towel. She had suffered extensive head injuries. Her clothes and personal possessions, including a handbag, were missing and were never found.

3. The appellant had visited the Island on a day trip from Mackay with his wife on the day on which Ms Douty was probably murdered. He left his wife for a period of about four hours telling her that he was going jogging or walking around the beach, around the island. When he returned to his wife he showed no signs of distress and there were no readily apparent marks or blood stains on him or on his clothing.

4. The red towel was found to have both blood stains and semen stains on it. The semen stains were located in six different places on the towel.

5. The sole evidence on which the appellant was convicted, apart from the fact that he had an opportunity to kill the deceased, was DNA evidence that it was his semen that was found on the red towel. The appellant did not give evidence.

6. The DNA tests, which it was said proved this, were done in February 1997. A DNA test of the appellant's blood sample on 6 February yielded a result; and a DNA test on a section of the towel which had been impregnated with semen, which was done on 13 February, yielded a matching result. The prosecution case at trial and the appellant's case on appeal depended and depends on the reliability of those tests. Mr Callaghan, for the appellant, in effect conceded that, if that DNA evidence was reliable, this appeal must fail on either ground.

7. Mr Callaghan did not dispute that the towel, from which sections were taken for the purpose of extracting DNA from semen and blood, presumably blood of the deceased, was the red towel which had covered the deceased's body. However he submitted nevertheless that there was a real risk that what purported to be DNA taken from semen on the towel was in fact DNA taken from a sample of blood (or possibly saliva) taken from the appellant. Consequently, he submitted, there was a reasonable hypothesis consistent with the appellant's innocence and the jury's verdict was therefore unsafe.

8. For Mr Callaghan's submission to be accepted, in those circumstances, two things must have occurred. They are:

1. during the processes which resulted in DNA tests on 6 February 1997 the sample of semen from which the disputed DNA was extracted must have become contaminated with the sample of blood (or possibly the sample of saliva) taken from the appellant;  and

2. for that to have had the consequence, consistent with the sample of semen from the towel not being that of the appellant, that the only DNA revealed by the test of that sample was that of the appellant, the semen must have been so degraded that it was impossible to extract DNA from it or so little in quantity, compared to that of the appellant's blood (or saliva) which contaminated it, that it was overwhelmed ("swamped" was the term used by counsel, but not by either of the experts, in the trial) by the contaminating blood (or saliva).

9. The reason why Mr Callaghan accepted that, if contamination occurred to the sample of semen on the towel from which DNA was said to have been extracted, it must have occurred on or before 6 February, is that, whilst on that date DNA tests were done on the sample of semen on the towel, on a sample of blood on the towel and on a sample of the appellant's blood taken from him, the only tests which were done after that date were on sections of the towel. Consequently there could have been no opportunity after that date for contamination of the semen on the towel with blood (or saliva) taken from the appellant.

10. The reason why he accepted that there had to have been a contamination by the appellant's blood of the semen sample, not a substitution of the appellant's blood sample for the semen sample, was that, if there had been a substitution, either what purported to show the result of the DNA test of the appellant's blood would have shown some DNA other than the appellant's or would have yielded no result. In fact the DNA test on 6 February of the appellant's blood sample yielded a result which it was accepted was the appellant's DNA. That is the reason why there was no further testing on the appellant's blood sample after 6 February and consequently no opportunity for contamination of other samples with his blood sample (or saliva sample) after that date.

11. It is necessary therefore to examine these possibilities to see whether their combination was one which was reasonably open on the evidence. Two experts gave evidence on this question, Mr Freney the supervising forensic scientist at the John Tonge Centre where all relevant tests were performed, and Dr Budowle an independent international expert.

12. It is worth making the point at the outset that, notwithstanding that the appellant had, as his adviser and potential witness at the trial, Dr Mullis, a Nobel Laureate who invented the fundamentals of the process by which modern DNA analysis is performed, this combination of possibilities in the given circumstances was never asserted by any expert witnesses. Moreover, although Dr Budowle accepted this combination as a hypothetical possibility, he rejected it as a realistic possibility for reasons we shall shortly refer to. A quite different and specific theory of contamination (that contamination occurred after 6 February and before 13 February), apparently emanating from Dr Mullis, was put to Dr Budowle by defence counsel and was rejected by him.  This theory was, in the end, abandoned by the defence and Dr Mullis did not give evidence.

Contamination

13. Mr Callaghan submitted that the fact that DNA tests on a semen sample from the towel failed to yield a result on 6 February but that a DNA test on that sample on 13 February did yield a result supported the contention that there had been contamination of the sample.  And he submitted that the systems which were in place at the John Tonge Centre where these tests were performed were such as not to exclude contamination as a reasonable possibility.

14. Of the six sections of towel on which semen had been detected, only one was, in the end, submitted to DNA testing. It was divided into two, given the numbers 12150A and 12150B. On 6 February the sample labelled 12150B was tested for DNA as were also a section of the towel stained with blood, presumably that of the deceased, and a sample of the appellant's blood. Only the appellant's blood sample yielded a result.

15. On 13 February sample 12150B was again submitted to DNA testing, as was also the blood sample on the towel. On this occasion a substance known as BSA was added, the purpose being to overcome the effect of any inhibitors to the process by which DNA is extracted. As Dr Budowle explained, such inhibitors may be present in the form of dyes in a towel. Indeed, because of the risk of presence of such inhibitors, BSA is now part of the routine testing kit but it was not at the time these tests were done. On this occasion a result was obtained from each sample.

16. It is difficult to see how the difference between the results on 6 February and 13 February raised a reasonable possibility of contamination on or before 6 February.  The evidence of both Mr Freney and Dr Budowle is that there may be many reasons for a DNA test failing to yield a result.  However the fact that on the first of those dates no DNA could be obtained either from semen or from blood on the towel and that, on the second, DNA tests were positive on both, supports the inference that it was the presence of BSA on the second of these occasions which accounted for the difference.  This was the unintentional control mechanism to which we refer later.

17. Mr Callaghan sought to rebut this inference by the fact that no result was obtained from sample 12150A and that, according to Mr Freney's "belief", BSA had also been added to that sample for testing. However, as mentioned earlier, there may be many reasons for that. The reason why no result was obtained from this sample was not fully explored in evidence and no attempt was made to verify or contradict Mr Freney's "belief" by seeking to tender the relevant contemporaneous records. That was no doubt because Mr Freney said that that sample contained so little DNA that it was not worth persisting with it but that if they had they may well have obtained a result. Having obtained a result from the other sample, he said, it was not worthwhile persisting with this one. So the failure to obtain a result from sample 12150A was simply inconclusive.

18. It was then submitted that the system in operation at that time permitted a realistic possibility of contamination by mixing of samples. Evidence of the system and procedures then in place was given by Mr Freney. His evidence was aided in this respect by the case file which showed, in some detail as he explained, the steps which were taken, and the dates on which they were taken, leading up to and including the DNA analyses of the appellant's blood sample, a sample of blood on the towel and sample 12150B. The jury were instructed by Mr Freney on the manner in which that file should be read.

19. It is unnecessary to set out in detail the system and procedures which were in place at the relevant time to prevent error and contamination. These were deposed to by Mr Freney and, in some cases, for example the system of double and treble checking, they appear from the case file itself.

20. Dr Budowle expressed his approval of these systems and procedures and, on that basis and on the basis that there was an obvious explanation for the failure to obtain a result from testing of samples of the towel on 6 February, expressed the view that contamination was not a plausible explanation for what occurred either in the course of conduct leading to the DNA analyses on 6 February or in the course of conduct leading to the DNA analyses on 13 February.  Moreover, as the experts showed, if contamination occurred, there would ordinarily be evidence of both DNAs appearing in the result of the analysis of semen stained towel on 13 February, whereas that was not the case here.  It would be only where the level of one was so low as to be undetectable that that would not occur.  The possibility of that occurring, even if there were contamination, is discussed in the next section of this judgment.

21. It should also be noted that whilst DNA analyses of the semen stains on the towel and the appellant's blood sample were conducted on 6 February, the samples were cut and sealed on earlier and different days. Consequently they were not both exposed to the air at the same time, excluding the possibility of contamination, one with the other, during this process.

22. The jury were entitled to accept the evidence of Mr Freney and Dr Budowle. Indeed it would have been surprising if they had rejected it, given the expertize of these witnesses and the absence of any evidence to the contrary.

Degradation and swamping

23. As already mentioned there was no dispute that the section of towel from which the disputed DNA was extracted was a section of the towel which had partly covered the body of the deceased. But Mr Callaghan submitted that the condition in which the towel had been kept between the murder and the DNA analyses may have precluded the extraction of DNA from semen on it.

24. Mr Callaghan submitted that, over the 13½ years between the murder and the DNA analyses, the towel had been in a number of places and that there was no satisfactory evidence of the condition in which, at all times, it had been kept. Consequently, it was submitted, factors such as moisture, sunlight or heat could have so degraded the sample of semen from which the DNA was said to have been extracted that it was impossible to extract DNA from it. This, it was said, explained how, if that section of towel was contaminated by the appellant's blood sample, only the appellant's DNA was shown on testing it. There were, however a number of indications that this was not the case.

25. In the first place a period of 13½ years is not, in DNA terms a long time. Good results have been obtained 20 or 30 years after the event and Dr Budowle even gave the example of DNA extracted from bones 60,000 years old. If the substance containing it is dry and out of sunlight it will not degrade for many years.

26. Secondly, there is nothing to indicate that any of the conditions which could have caused even partial degradation, in particular moisture or heat or direct sunlight, existed in respect of the towel at any time. It was dry when Mr Freney took possession of it two days after the murder and it was always kept dry, indoors and, it seems, in a plastic bag, albeit with other things.

27. Thirdly, one of the advantages of the process by which DNA is extracted, so Dr Budowle said, is that unlike earlier processes such as the ABO process referred to later, partial degradation does not prevent good results from being obtained.  That is because, unlike the other processes, it focuses on very small portions of the DNA, a few hundred letters long at the most.  These may be mere fragments of DNA.

28. Fourthly, Mr Freney was able to microscopically observe sperm cells on the section of towel from which the DNA was extracted. And he said that if the cells were microscopically visible there must have been DNA which was extractable. If contamination occurred in that event then, provided the contaminating DNA was more than 10 per cent of the DNA extracted, there would be a mixed profile. That did not occur. For the contaminant to have overwhelmed the DNA from the semen to the point where there was no reading for the latter, that latter would have to have been so degraded or small in amount that it represented less than 10 per cent of the DNA profile. In Dr Budowle's opinion that was a hypothetical possibility but not, in these circumstances, a real one.

29. And fifthly there was, in any event, what Dr Budowle described as an unintentional control mechanism namely that the tests on 13 February which revealed DNA from the semen sample also revealed DNA in blood on the towel, apparently the blood of the deceased; certainly not that of the appellant. Dr Budowle thought that there was no reason in this case why the semen would degrade at any faster rate than the blood, both having existed in the same environment.

30. Dr Budowle did not think that degradation was a realistic possibility and there is no reason why the jury should not have accepted his evidence. Those conclusions are, subject to one matter, sufficient to reject any challenge to the reliability of the DNA evidence and consequently to require dismissal of the appeal.

The ABO test

31. That was the performance of a test known as the ABO test in 1983 and the result of that test which appeared to exonerate the appellant. Since DNA testing was introduced this test is no longer performed. However the fact, which is uncontested, that DNA testing yields a more certain result is not sufficient to explain why the ABO test was wrong.

32. That test was said to reveal that semen on the towel indicated that it came from a group O secretor. The appellant was a group B secretor. It was therefore assumed, before DNA tests were done in February 1997, that the semen could not be his.

33. All six places on the towel where semen was found were tested. Only one of them gave a result and it was that one which yielded a group O secretor reaction. However a group O secretor reaction can be obtained from group A blood or group B blood if either is exposed to moisture, ultraviolet light or bacteria or if, for any other reason, the sugars in the sample break down. Some of these are problems which affect DNA testing, but not to anything like the same degree, because DNA is extracted from cells whilst ABO testing is done on bodily fluids; and because cells have very strong walls they are much less prone to degradation and, as mentioned earlier, DNA may be extracted even where degradation has occurred.

34. Moreover the deceased was group O blood type and the likelihood was that, like most people she was a secretor so that the ABO test result could have revealed her secretion, not that of the depositor of the semen. Of the six places where the test was performed, the only one which yielded a result was from a section where the spermatozoa count was weakest.

35. For these reasons the jury was justified in rejecting the ABO test as casting doubt on the reliability of the DNA tests.

36. For those reasons, in our opinion, the appeal must be dismissed.