ARGENT -v- THE STATE OF WESTERN AUSTRALIA [2026] WASCA 40 (25 March 2026)

1. Both the State and Mr Argent called evidence from DNA experts at trial. The State called evidence from Louise King and Mr Argent called evidence from Brian McDonald.
2. To put their evidence into context, it is necessary to summarise a number of other aspects of the evidence at trial.

1. In addition to Mr Argent and Ms Munroe, reference DNA profiles were obtained from a number of other individuals. Those individuals, and their involvement in the trial, were as follows.

1. On the night of 14 May 2018, Clinton Duncan was at a camp on a concrete slab about 60 m away from Mr Argent and Ms Munroe's campsite. Police woke Mr Duncan on the morning of 15 May 2018 and spoke with him.[1]
2. Mr Duncan gave evidence at trial. He confirmed being woken by police and said that between the time he went to sleep and when the police woke him, he did not hear anything. Mr Duncan gave evidence that earlier in the night, when it was dark, he saw Mr Argent and called out to him to offer him a drink.[2] He also gave evidence that Ms Munroe was his 'cuz' and that he neither saw her, nor had a fight with her, that night.[3]
3. In his own evidence, Mr Argent said that he saw Mr Duncan and others as he and Ms Munroe walked back to their camp. He said that they told him to stop arguing.[4] Mr Argent said in cross‑examination that he had never seen those people fight with Ms Munroe and that, as he walked past them, it seemed like they were worried about her.[5]

1. Marshall Burke was at the concrete slab campsite with Mr Duncan when Mr Argent and Ms Munroe were walking to their camp. He too was woken by police on the morning of 15 May 2018.
2. A statement from Mr Burke was read into evidence. He confirmed being woken by police on the morning of 15 May 2018. He said that at no time while he was drinking and sleeping at the camp did he hear anyone fighting or arguing. He said that he did not see Mr Argent or Ms Munroe at that time.[6]

1. Brendan Lawson was also at the concrete slab campsite with Mr Duncan and Mr Burke during the night of 14 May 2018. Mr Duncan gave evidence that after he had spoken to Mr Argent, and when he and Mr Burke went to sleep, Mr Lawson 'went to his missus'.[7] A police officer, Senior Constable Jamie Buck, gave evidence that she arrested Mr Lawson on an unrelated matter at about 2.00 am on 15 May 2018. Senior Constable Buck said that when Mr Lawson was arrested he was calm, compliant, sleepy and apologetic.[8]

1. Theresa Duncan was Mr Burke's partner and Mr Duncan's mother. Ms Munroe was her niece. She gave evidence that on the night that Ms Munroe died she was at a 'woman's refuge' in Kalgoorlie.[9] Tira Te Nana, a support worker at the Goldfields Woman's Refuge gave evidence, by reference to the records of the refuge, that Ms Duncan was at the refuge from 6.45 pm on 14 May 2018 to 8.34 am on 15 May 2018.[10]
2. Ms Duncan gave evidence that in the days prior to Ms Munroe's death, she and Mr Burke went to another camp near 'Marshall's camp'. She said that she sat down on a mattress there. Ms Duncan also gave evidence that she had never fought with her niece.[11]

1. In his record of interview with police, and in a statement to police that was adduced in evidence, Mr Argent said that when he woke Ms Munroe up in the early hours of 15 May 2018 (having returned to the camp after being in town), Ms Munroe 'shouted out a bloke's name "Casey Jones"'.[12] He also gave that evidence at trial.[13]
2. Mr Jones gave evidence that Ms Munroe was his cousin. He said that his sister told him about Ms Munroe's death on the morning after it had occurred. Mr Jones said that at that time he was living in the bush at Ninga Mia with his sisters and his niece.[14] He also gave evidence that he had not had any fights with Ms Munroe and that he had 'never seen her all those weeks'.[15]

1. Police obtained a number of exhibits that were the subject of DNA analysis. Those that are relevant to Mr Argent's appeal are as follows.
2. We have already referred to the tree branch and the brick paver, which were identified as JSE1 and JSE2 respectively. Both the tree branch (JSE1) and the brick paver (JSE2) were located at the bush camp where Ms Munroe was found.[16]
3. Also at the bush camp, inside a blanket, police located a smaller stick, which was identified as JSE35.[17] The smaller stick (JSE35) was approximately 284 mm in length.[18]
4. Finally, at the bush camp, police located a number of cigarette butts. One of those cigarette butts, which was located on the mattress at the bush camp, was identified as JSE44.[19] The other cigarette butts were identified as JSE43 and JSE45.
5. A number of forensic tests were also carried out from samples taken from Ms Munroe, including a fingernail scraping from the ring finger of her left hand (identified as DRE4), a fingernail scraping from the ring finger of her right hand (identified as DRE11), and a fingernail scraping from the index finger of her right hand (identified as DRE14).[20]

1. Ms King, who was called by the State, is a forensic scientist with PathWest. Her expertise in relation to the examination of crime scene exhibits and the interpretation of DNA profiles was not the subject of any contest at trial.
2. Ms King compiled a report in relation to the DNA analysis of exhibits in relation to the investigation of Ms Munroe's death, dated 7 November 2019. She also prepared an additional witness statement dated 29 November 2019, in relation to additional tests carried out at the request of Mr Argent's counsel, Mr J A Davies. While Ms King's report and witness statement were not tendered in evidence, her evidence was given with the assistance of those materials, and the PathWest case file.
3. Ms King gave evidence over the course of two days. She was thoroughly and competently cross‑examined. Her evidence, in relation to the items relevant to Mr Argent's appeal included the following.

1. Ms King gave evidence that a red‑brown stain on the thicker end of the tree branch (stain A) gave a positive result for the presumptive chemical test for blood. DNA analysis of that stain recovered a single source DNA profile matching Ms Munroe (greater than 100 billion times more likely that it came from Ms Munroe than not).[21]
2. Ms King gave evidence that swabs were taken from the surface of the tree branch (avoiding the red‑brown staining) for DNA analysis.[22] Two of the swabs were taken from the middle section of the tree branch and the narrow end of the tree branch respectively.
3. In relation to the middle section of the tree branch, Ms King gave evidence that analysis of that section could not reliably determine the number of contributors present within the mixed DNA profile and therefore no interpretation was carried out in relation to the sample.[23]
4. Ms King gave evidence that the narrow end of the tree branch gave a positive result for the presumptive chemical test for blood, with a mixed DNA profile consistent with having come from three individuals. Comparison with the reference DNA profiles revealed that:[24]

(a) one contributor matched Ms Munroe (greater than 100 billion times more likely that Ms Munroe was a contributor than not);

(b) one contributor matched Mr Argent (1.4 billion times more likely that Mr Argent was a contributor than not);

(c) Mr Jones was excluded as a contributor;

(d) Mr Burke was excluded as a contributor;

(e) Mr Duncan was likely not a contributor;

(f) Mr Lawson had a statistic for inclusion of 12; and

(g) Ms Duncan had a statistic for inclusion of 130.

1. Ms King explained the statistic for inclusion of 12 and 130 (relating to Mr Lawson and Ms Duncan respectively), as follows:[25]

So in our laboratory, we can report a statistic anywhere from two, all the way up to 100 billion. The greater the number, the greater the support for inclusion. The lower the number, the weaker the support for inclusion. We know there is a figure of around one million that may suggest anything under one million may be within the coincidental range supporting inclusion. And I would certainly say that a statistic of 12 and 130 is very low evidence and well within this coincidental range that it may be.

1. Ms King gave evidence that two red‑brown stains on the brick paver (stain A and stain B) both gave a positive result for the presumptive chemical test for blood.[26] DNA analysis of both stains recovered a single source DNA profile matching Ms Munroe (greater than 100 billion times more likely that it came from Ms Munroe than not).[27]
2. Ms King gave evidence that analysis of the surface of the brick paver (avoiding the red‑brown staining) recovered a mixed DNA profile consistent with having come from three individuals. Comparison with the reference DNA profiles revealed that:[28]

(a) one contributor matched Ms Munroe (greater than 100 billion times more likely that Ms Munroe was a contributor than not);

(b) one contributor matched Mr Argent (3.6 billion times more likely that Mr Argent was a contributor than not);

(c) Mr Jones was likely not a contributor;

(d) Mr Burke was likely not a contributor;

(e) There was no evidence to support the inclusion or exclusion of Mr Duncan (a neutral finding);

(f) Mr Lawson was likely not a contributor; and

(g) Ms Duncan had a statistic for inclusion of 2.

1. Ms King explained that the statistic for inclusion of 2 (relating to Ms Duncan) was the lowest statistic that could be reported in favour of inclusion and was very weak evidence. She said that she would expect one in two people to give a statistic within this magnitude.[29]

1. Ms King gave evidence that there were several stains on the smaller stick which produced a positive result for the presumptive chemical test for blood and a single source DNA profile matching Ms Munroe (greater than 100 billion times more likely that it came from Ms Munroe than not).[30]
2. The two ends of the smaller stick (avoiding the areas of visible staining) were analysed for DNA.
3. Ms King gave evidence that one end of the smaller stick (end A) recovered a mixed DNA profile for three individuals. One contributor, who contributed substantially more DNA to the mixture than the other two, matched Ms Munroe (greater than 100 billion times more likely that Ms Munroe was a contributor than not). Ms King gave evidence that she could not make any comparisons in relation to the other two individuals present within that mixed DNA profile and that the profile was not suitable for further interpretation.[31]
4. In relation to the other end of the smaller stick (end B) a mixed DNA profile consistent with having come from three individuals was recovered. Comparison with the reference DNA profiles revealed that:[32]

(a) one contributor matched Ms Munroe (greater than 100 billion times more likely that Ms Munroe was a contributor than not);

(b) one contributor matched Mr Argent (1.2 million times more likely that Mr Argent was a contributor than not);

(c) Mr Jones was likely not a contributor;

(d) Mr Burke was likely not a contributor;

(e) Mr Duncan was likely not a contributor;

(f) Mr Lawson was likely not a contributor; and

(g) Ms Duncan was likely not a contributor.

1. Ms King gave evidence that there were two areas of the cigarette butt (JSE44) that were tested: an area that was stained with red‑brown staining and a portion from the filter paper that avoided that staining.
2. In relation to the portion from the filter paper, Ms King said that a mixed DNA profile was recovered but that the number of contributors could not be reliably identified such that she was unable to make any interpretation. In relation to the stained area, tests produced a positive result for the presumptive chemical test for blood and a single source DNA profile matching Ms Munroe (greater than 100 billion times more likely that it came from Ms Munroe than not).[33]

1. Ms King was not asked about the samples taken from Ms Munroe's fingernails in evidence‑in‑chief.
2. The samples were, however, addressed in cross‑examination.
3. In relation to the sample from the ring finger of Ms Munroe's left hand, Ms King gave evidence that a mixed DNA profile in the sample was not suitable for interpretation, as she was unable to confidently assign the number of contributors present in the sample. Prior to trial, the defence had requested that the sample be 'deconvoluted as a 3 and/or 4 person sample, in order to identify any possible profiles'.[34] Ms King gave evidence that she had not done so as it was not scientifically sound to do so.
4. Her evidence included the following:[35]

Now, you did rerun that as a four‑person mix, didn't you, have a look at it as a four‑person mix?---No. I did not.

You didn't. What, in fact, did you do as a result of that request?---I disagreed with the number of contributors in this mixed DNA profile. Initially, this mixed DNA profile was reported as a mixture not suitable for interpretation. I have not compared anyone to this mixed DNA profile. It's more conservative to say nothing than to include or - to include someone falsely. I - - -

So you understand - sorry. Complete your question. I beg your pardon. Complete your answer?--- (indistinct) I am unable to (indistinct) confidently assign the number of contributors present within this mixed DNA profile, and it's not scientifically sound for me to make any comparisons to this profile. Comparisons made to this profile may include false inclusions or exclusions and would be anticonservative. Six other forensic scientists agree with me for this mixed DNA profile, and they have all deemed it as a mixture not suitable for interpretation.

Well, you understand that other scientists, apart from those scientists in PathWest, can disagree. You accept that, don't you?---Yes.

And you accept, don't you, that Dr Brian McDonald has said that it is possible, reasonably possible, that this can and should be analysed as a three or a four‑person mixtures and the results run against the database?---Yes. My work is peer reviewed, and it has been reviewed by six other people.

It has, but, nonetheless, you have refused to run those deconvoluted samples against the database, notwithstanding the request of the defence?---The request to interpret this mixed DNA profile as either originating from three or four individuals further demonstrates the uncertainty inherently associated with the quality of this sample.

Perhaps we can put it this way. The answer to the question is yes. You have refused. You may have your reasons for that, but you have refused, haven't you?---I have refused because I don't think this is suitable for interpretation.

1. The sample from the ring finger of Ms Munroe's right hand was not expressly referred to in the cross‑examination, although Ms King gave evidence in relation to the sample from the index finger of Ms Munroe's right hand which addressed fingernail scrapings more generally:[36]

This sample is from a female scraping and, notoriously, they are quite difficult to recover DNA profiles from. We do get a lot of inhibition in samples from DNA scrapings and that can be seen in this profile and there is actually notes, on page 486 of this electropherogram, stating that a typical degradation is present within the sample.

Why is that DNA degraded?---Fingernail scrapings are not a great source of DNA. We know that we get a lot of inhibition from that, whether it's a bit of a nail that we're getting or the dirt that's under someone's fingernail scrapings, it is inhibiting the DNA processes that we have down screen. This sample was also reported as a mixture X, so I did not [consider] making any comparisons to this sample.

1. Dr McDonald is a scientist with many years' experience in the testing and reporting of DNA in the medical context. While the extent of his relevant experience was the subject of cross‑examination, Dr McDonald's qualification to give expert evidence was not contested.
2. Dr McDonald gave evidence that prior to trial he had advised the defence that a number of additional tests and analyses should be undertaken on the forensic exhibits.[37] It was based on that advice that the defence requested that additional tests and analyses be undertaken (such as that referred to in [52] above). A total of 11 such requests were made prior to trial.
3. Most of the matters raised by Dr McDonald prior to trial, and in his evidence, do not concern the issues in Mr Argent's appeal. A particular criticism that he did make of Ms King's analysis, in relation to the analysis of mixed DNA profiles (see [53] above), was expressly disavowed by counsel for Mr Argent in [38]e appeal.38
4. One aspect of Dr McDonald's evidence has some relevance to this appeal, which concerned a sample from the tree branch (JSE1). Dr McDonald gave evidence that he had requested a reanalysis of the data that came from that sample and that PathWest, instead, 're‑amplifie[d] the DNA sample and ran it again'.[39] When asked about that analysis, Dr McDonald gave evidence:[40]

Well, there was essentially no changes to the relative position for the major contributors. Some Y chromosome material appeared on the retesting that certainly wasn't visible on the first testing. There was again I think one minor peak and a loss of about six minor peaks. So there was less information about the minor contributors after re‑amplification. But PathWest was of the view that it was interpretable as a three person mixture and so then used that information to search the database.

1. Dr McDonald later confirmed, in relation to the second test of the sample, 'this particular mixture actually had less information in it than the first one. So it had lost information because it had failed to detect'.[41]

1. There are three grounds of appeal. As will be seen, all of the grounds are based on Mr Fuller's report. The grounds are as follows:

1. A miscarriage of justice occurred because the DNA evidence recovered from the 'weapons' used in the murder that implicated the Appellant was not properly examined:

(a) A DNA profile was recovered from the middle section of a stick (JSE1) but deemed too complex for further investigation. The sample was however diluted for amplification. This sample should have been re‑amplified with increased DNA template to possibly recover a DNA profile of higher quality.

(b) A mixed DNA profile assumed to have originated from 3 individuals was recovered from the narrow end of this stick. This DNA profile consisted of major and minor components. The sample was diluted for amplification. This sample should have been re‑amplified with increased DNA template to investigate the minor component.

(c) A mixed DNA profile was recovered from the paver (JSE2) which included a major and minor component. This sample was diluted for amplification. It should have been reamplified at the same dilution for investigation of the minor components across replicates.

(d) On the stick (JSE35 End A) a mixed DNA profile was recovered. The minor component was not examined. There are indications that at least 4 individuals may be contributing to this profile. This sample should have been re‑amplified with increased DNA template to investigate the minor component. A mixed DNA profile was recovered from End B of this stick. This sample should have been re‑amplified with increased DNA template to investigate the minor component.

1. A miscarriage of justice occurred because the DNA evidence from other sources at the 'scene' was not properly examined:

(a) A mixed DNA profile was recovered from a cigarette butt at the scene (JSE43). The major component originated from an unknown male. This should have been compared to all suitable evidence DNA profiles associated with this matter.

(b) A mixed DNA profile from a portion of filter paper from the mouth end of cigarette butt JSE44 was recovered. The sample was diluted for amplification. This sample should have been re‑amplified with increased DNA template for further investigation.

(c) A portion of the filter paper from another cigarette butt (JSE45) and was examined and a mixed DNA profile was recovered. The major component originated from an unknown female. This should have been compared to all suitable evidence profiles associated with this matter.

1. A miscarriage of justice occurred because the DNA evidence from the deceased's fingernails was not properly examined:

(a) A fingernail scraping was taken from the deceased's ring finger of her left hand. A mixed DNA profile was recovered. At least 3 individuals have contributed. This sample should be re‑amplified for further investigation across replicates.

(b) A fingernail scraping was taken from the ring finger of the deceased's right hand. This sample of mixed DNA should have been re‑amplified with increased DNA template to investigate the minor component.

(c) A mixed DNA profile was obtained from the deceased's right hand index finger. At least 2 individuals have contributed, and this profile is suitable for further interpretation. An STRmix analysis should have been done.

1. At the hearing of the appeal, counsel did not pursue grounds 2(a) and 2(c) of the grounds of appeal.[42] Those sub‑grounds were to the effect that two of the cigarette butts located at the scene (JSE43 and JSE45) ought to have been compared with all suitable DNA profiles associated with the matter. The reason that those sub‑grounds were not pursued is that the analyses referred to in those grounds were in fact carried out prior to trial and were the subject of evidence to the effect that no matches were identified.[43]
2. While these sub‑grounds were not pursued, their inclusion in the appeal is, nevertheless, instructive as to an important feature of Mr Fuller's report; namely, that Mr Fuller's report does not engage with any of the evidence at trial. This is not a criticism of Mr Fuller. It is apparent from his report that Mr Fuller was not provided with a copy of the evidence at trial, including the evidence of Ms King or Dr McDonald. Nevertheless, this feature of Mr Fuller's report does assist in understanding the report as a whole, to which we now turn.

1. Mr Fuller is a forensic scientist who was employed by PathWest from 2008 to 2023, including as a Senior Reporting Forensic Scientist from 2012.
2. Before identifying the particular passages of Mr Fuller's report relied upon by Mr Argent in the appeal, it is appropriate to make some general observations in relation to the report.

1. As we have already observed, Mr Fuller's report does not engage with the evidence at trial. It does not, for example, suggest that any of the evidence given by Ms King in relation to her analysis of the exhibits provided to her was wrong or take issue with any of the opinions that she gave.
2. Rather than calling into question any of the evidence given at trial, Mr Fuller's report bears many of the hallmarks of a comprehensive 'cold‑case' review. That is, Mr Fuller systematically addresses all of the items located at the bush camp and on Ms Munroe's body, identifying possible further enquiries that could be made. As Mr Fuller says in his summary of conclusions:[44]

A number of samples have been identified where IN MY OPINION, additional analysis and/or DNA profile interpretation should be performed, or at least considered.

1. The reference to 'should be performed, or at least considered' (emphasis added) is telling. It reveals that Mr Fuller is identifying all potential lines of enquiry that may be appropriate, but without knowledge of the broader context as to the utility of those enquiries. We have already referred to the example of two of the cigarette butts located at the scene (JSE43 and JSE45). Another good example of this is how Mr Fuller addresses the low statistical evaluation that Ms Duncan might be a contributor to the mixed DNA profiles on the tree branch (JSE1) and brick paver (JSE2). Mr Fuller reports that the 'history and activities of Theresa DUNCAN and these items should be thoroughly examined'. As, of course, they were, in the trial.
2. Mr Fuller's report, accordingly, includes a great many suggestions for further enquiries that are not included in the appeal.
3. Those portions of Mr Fuller's report that are relied upon in the appeal are as follows.

Middle section of the tree branch (JSE1) - ground 1(a)

1. In relation to the middle section of the tree branch (JSE1), Mr Fuller reported:[45]

A mixed DNA profile was recovered but was deemed too complex for further interpretation.

IN MY OPINION, due to variability in contributor proportions, I agree this DNA profile is not suitable for further interpretation. Having said this, the sample was diluted for amplification. This sample should be re‑amplified with increased DNA template to possibly recover a DNA profile of higher quality.

1. In relation to the narrow end of the tree branch (JSE1), Mr Fuller, having reported the findings summarised at [39] above[46]reported:46

As the number of named individuals exceeds the number of assumed contributors to this mixed DNA profile one or more of these findings is coincidental.

IN MY OPINION, given the low likelihood ratios favouring contribution associated with Theresa DUNCAN and Brendon LAWSON (sic), it is more likely that one or both of these findings are coincidental, than if the findings associated with Cynthia MUNRO (sic) and Adrian ARGENT are coincidental. This sample was diluted for amplification. This sample should be re‑amplified with increased DNA template to investigate the minor component.

1. In relation to the brick paver (JSE2), Mr Fuller, having reported the findings summarised at [42] above[47]reported:47

IN MY OPINION, the low likelihood ratio favouring inclusion associated with Theresa DUNCAN could reasonably be explained by adventitious inclusion. I would expect every 2nd individual from the Australian population, unrelated to Theresa DUNCAN, to yield a statistic of the same magnitude or greater.

This sample was diluted for amplification; however, the DNA profile is already presenting with minor artefacts. Re‑amplification with increased DNA template is not recommended. IN MY OPINION, this sample should be re‑amplified at the same dilution for investigation of the minor component across replicates.

1. In relation to end A of the smaller stick (JSE35), Mr Fuller reported:[48]

The minor component was deemed not suitable for further interpretation due to the possible presence of additional contributors.

IN MY OPINION, there are indications that at least four individuals may be contributing to this mixed DNA profile. This sample was diluted for amplification. This sample should be re‑amplified with increased DNA template to investigate the minor component.

1. In relation to the cigarette butt (JSE44), Mr Fuller reported:[49]

Portion of filter paper (mouth end)

A low‑level mixed DNA profile was recovered but was deemed too complex for further interpretation.

IN MY OPINION, at least two individuals are contributing to this mixed DNA profile. This sample was diluted for amplification. This sample should be re‑amplified with increased DNA template for further investigation.

Fingernail sample from the ring finger of left hand (DRE4)

1. In relation to the fingernail sample from the ring finger of Ms Munroe's left hand (DRE4), Mr Fuller reported:[50]

A mixed DNA profile was recovered but was deemed too complex for further interpretation.

IN MY OPINION, at least three individuals have contributed to this low‑level mixed DNA profile. This sample should be re‑amplified for further investigation across replicates.

Fingernail sample from the ring finger of right hand (DRE11)

1. In relation to the fingernail sample from the ring finger of Ms Munroe's right hand (DRE11), Mr Fuller reported:[51]

A mixed DNA profile assumed to have originated from two individuals was recovered. The mixed DNA profile consisted of major and minor components. The major component matched the reference DNA profile listed as from Cynthia MUNRO (sic). The minor component was deemed not suitable for further interpretation due to limited information.

This sample was diluted for amplification. IN MY OPINION, this sample should be re‑amplified with increased DNA template to investigate the minor component.

Fingernail sample from the index finger of right hand (DRE14)

1. In relation to the fingernail sample from the index finger of Ms Munroe's right hand (DRE14), Mr Fuller reported:[52]

A mixed DNA profile was recovered but was deemed too complex for further interpretation, due to variability in contributor proportions throughout the profile.

IN MY OPINION, at least two individuals have contributed to this mixed DNA profile and it is suitable for further interpretation. The contributor proportions are largely consistent and STRmix analysis is intuitive.

1. The common law courts have always reserved to themselves an exceptional power to set aside a verdict on the ground of further evidence where the interests of justice require it.[53] While the grounds upon which that power will be exercised have always possessed some flexibility, various guiding principles have been developed that seek to balance the interests of justice in the individual case with the public interest in the finality of legal proceedings.[54]
2. Those guiding principles draw a distinction between fresh evidence and new evidence. Fresh evidence is evidence that either did not exist as at the date of the trial or could not, with reasonable diligence, have been obtained or discovered for use at the trial. New evidence is evidence that could, with reasonable diligence, have been obtained or discovered for use at the trial.[55]
3. Where an accused has been convicted, an appellate court will not allow an appeal on the basis of new, as distinct from fresh, evidence unless the new evidence establishes that the appellant is innocent or the new evidence raises such a doubt that the court is satisfied that the appellant should not have been convicted. Where an accused has been convicted, an appellate court will not allow an appeal, on the basis of fresh as distinct from new evidence, unless there is a 'significant possibility' that, on the basis of all of the admissible evidence (that is, the fresh evidence and the evidence given at trial), a jury, acting reasonably, would have acquitted the appellant.[56]
4. These principles concerning new and fresh evidence continue to guide the determination of whether there was a miscarriage of justice at the trial within s 30(3)(c) of the Criminal Appeals Act 2004 (WA), although the determination of whether there was a miscarriage of justice does not involve the rigid application of those principles.
5. In light of these principles, we turn to the present case.

1. For the reasons that follow, in our view, nothing in Mr Fuller's report arguably supports the conclusion that there has been a miscarriage of justice in the present case.
2. We commence with whether Mr Fuller's report is fresh or new evidence. Mr Argent contended that Mr Fuller's report was fresh evidence. In that regard, counsel submitted that the issues raised by Mr Fuller were outside the scope of Dr McDonald's experience and that Mr Fuller was not available to give the evidence at the time of trial. Counsel submitted that the evidence given by Mr Fuller 'wasn't reasonably available because there wasn't a suitably qualified expert at the time'.[57]
3. We reject that submission. There was no evidence before this Court as to the availability of persons, in 2019, able to provide opinions of the kind proffered by Mr Fuller in his report. Indeed, common sense and the common experience of the courts would suggest otherwise. The extraction and analysis of DNA material is by no means an obscure or occult field of study, nor was it in 2019. Many scientists are likely to have been able to address the issues raised by Mr Fuller. As we have noted above, for example, it is apparent from Dr McDonald's evidence that he was well aware of the capacity for DNA samples to be 're‑amplified' for further analysis, where it is appropriate to do so, which was the basis for many of Mr Fuller's suggested actions. Indeed, it is apparent from the lengthy and thorough cross‑examination of Ms King, that trial counsel for Mr Argent was himself possessed of significant background understanding of DNA analysis that enabled him to raise many technical issues in the course of cross‑examination. The fact that a particular expert may not have been available to give evidence at the time of trial does not support the conclusion that such evidence was not, with reasonable diligence, available at trial.
4. For these reasons, Mr Fuller's report was, at best, new evidence, as that expression is used in the cases.
5. We say 'at best' because, in one sense, Mr Fuller's report is not evidence at all. That is, there is a real question as to whether Mr Fuller's report would have been admissible at trial. It does not, for example, add to the information that was gained by the evidence adduced at trial in relation to the DNA profiles extracted from the various exhibits. What it does, rather, is suggest lines of inquiry that might have produced additional information as to those DNA profiles. The evidence at trial, for example, revealed that the analysis of the brick paver (avoiding the red‑brown staining) recovered a mixed DNA profile consistent with having come from three individuals, being Mr Argent, Ms Munroe and an unknown individual (the statistic match for Ms Duncan being likely coincidental). Mr Fuller's opinion that the sample could, or should, be re‑amplified would not change the evidence as to the number of contributors to the sample, or their identity, at all.
6. The same could be said of all Mr Fuller's opinions relied upon in the appeal. Mr Fuller's opinion that the other samples could, or should, have been the subject of further testing or analysis would not have advanced the evidence at trial as to the number of contributors, or their identity, of any of the samples.
7. It may be that, had Mr Fuller's report been expressed as a criticism of the quality or competence of the DNA analysis carried out by Ms King, that evidence might have been relevant and admissible at trial. Such an opinion might, for example, be deployed for the purpose of undermining the reliability of Ms King's analysis generally (including the presence of Mr Argent and Ms Munroe's DNA on the exhibits). But, in our assessment, Mr Fuller's report does not contain any express or implied criticism of the analysis carried out by Ms King. It is, as we have said, more in the nature of a comprehensive 'cold‑case' review report.
8. In that regard, the submission - reflected in the opening words of each ground of appeal - that the DNA evidence was 'not properly examined' must be rejected. That is not what Mr Fuller's report says and is not, in our assessment, what it means. The use of the word 'should' (e.g., 'this sample should be re‑amplified') does not itself connote a criticism. Particularly in light of Mr Fuller's report read as a whole, Mr Fuller's suggested inquiries cannot be construed as criticisms of Ms King or of her analysis.
9. Ultimately, in any event, whether Mr Fuller's report is properly characterised as fresh or new evidence, it does not support the conclusion that there has been a miscarriage of justice.
10. Applying the principles identified in relation to new evidence, there is nothing in Mr Fuller's report remotely capable of establishing that Mr Argent is innocent or that raises a doubt as to whether Mr Argent should have been convicted. As we noted at the outset, the State's circumstantial case that Mr Argent was Ms Munroe's killer was strong. They were in a domestic relationship which was the subject of significant strain. Mr Argent was the last person to be seen with Ms Munroe alive, during which time he was kicking and punching her. It was established that Ms Munroe's cause of death was blunt force injury to the head and bloodied items at the scene included Mr Argent's DNA; and did not match the DNA of any other persons seen in the vicinity of the area, or the person who Mr Argent implicated.
11. All of these circumstances amply supported the conclusion that the only reasonable inference was that Mr Argent killed Ms Munroe. None of the opinions of Mr Fuller (or the processes or analyses proposed by him) called into doubt any of those circumstances.
12. Mr Fuller's suggestions to 're‑amplify' the samples relating to the tree branch (JSE1), the brick paver (JSE2) and the smaller stick (JSE35) - relied upon in ground 1 - do not do so. The fact that there were mixed DNA samples in relation to those items and that the 'minor components' had not been identified was already in evidence before the jury. Evidence that further tests might identify the minor component does not, itself, add to the known facts as to Ms Munroe's death.
13. The prospect that 're‑amplification' might reveal one or more of the identities of the mixed DNA profile on the cigarette butt (JSE44) - relied upon in ground 2 - similarly adds nothing to the known facts. Indeed, the fact that there would be a mixed DNA sample on a cigarette butt at the scene was entirely unremarkable, given the evidence in relation to Mr Argent looking for 'bumpers'. It could in no way establish that Mr Argent is innocent or raise a doubt as to whether he should have been convicted.
14. The fingernail samples - referred to in ground 3 - received comparatively less attention at trial than the other samples. Nevertheless, Ms King gave evidence that there were mixed DNA profiles in Ms Munroe's fingernail samples and her evidence in relation to the limitations on the analysis of those samples was explored in cross‑examination. Again, evidence that further tests might identify the contributors does not add to the known facts.
15. Similarly, applying the principles identified in relation to fresh evidence, there is no 'significant possibility' that, if Mr Fuller's report was included within the evidence given at trial, a jury, acting reasonably, would have acquitted Mr Argent. On the contrary, for the reasons we have given, a jury, acting reasonably, would reach precisely the same conclusion, whether Mr Fuller's report was in evidence, or whether it was not. That is because the report added nothing to what the jury already knew. To invite the jury to place any weight on the fact that other tests or analysis could have been undertaken, without knowing what, if anything, those tests or analyses would have revealed, would have been to invite the jury to speculate. That would be inconsistent with a jury 'acting reasonably'.

1. The grounds of appeal are not reasonably arguable. Leave to appeal on each ground should be refused. The appeal must be dismissed.

I certify that the preceding paragraphs comprise the reasons for decision of the Supreme Court of Western Australia.

[12] Exhibit 22 (Statement). In his record of interview (Exhibit 21), Mr Argent said that Ms Munroe 'sang out' the name Casey Jones.

[20] Trial ts 485 - 487. The record of the trial, while referring to the fingernail scrapings, does not refer to the identifiers for the exhibits. Those identifiers, however, appear in Mr Fuller's report.

[44] Report of Kynan Rhys Fuller dated 1 November 2023, 3.

[45] Report of Kynan Rhys Fuller dated 1 November 2023, 5.

[46] Report of Kynan Rhys Fuller dated 1 November 2023, 6.

[47] Report of Kynan Rhys Fuller dated 1 November 2023, 7.

[48] Report of Kynan Rhys Fuller dated 1 November 2023, 7 - 8.

[49] Report of Kynan Rhys Fuller dated 1 November 2023, 9.

[50] Report of Kynan Rhys Fuller dated 1 November 2023, 11.

[51] Report of Kynan Rhys Fuller dated 1 November 2023, 13.

[52] Report of Kynan Rhys Fuller dated 1 November 2023, 14.

[53] CDJ v VAJ [1998] HCA 67; (1998) 197 CLR 172, [105] (McHugh, Gummow & Callinan JJ).

[54] McCann v Parsons [1954] HCA 70; (1954) 93 CLR 418, 430 - 431 (Dixon CJ, Fullagar, Kitto & Taylor JJ).

[55] Calabro v The State of Western Australia [2024] WASCA 10 (Calabro) [160] (Buss P, Mazza & Mitchell JJA).

[56] Calabro [160] (Buss P, Mazza & Mitchell JJA).