R v MK

The DNA Evidence 15The swabs from the complainant and the respondent were subject to analysis by the DAL. Counsel at first instance and his Honour used the phrase "DNA Evidence" to describe the evidence the Crown sought to adduce as to the analysis undertaken, the results and any explanation necessary to explain them. I am using the same terminology. 16The DNA evidence was given on behalf of the Crown by a DAL analyst, Ms Michele Franco. She provided a report which contained, inter alia, a description of the testing undertaken on the underpants and shorts of the complainant. The critical parts of her report concerned testing on "area 2aii", being the hip area of the complainant's underpants, and "area 2bi", being the "left hip area of the shorts". The report described the results of the testing on those areas as follows: "2aii Hip area of underpants DNA testing (using the Profiler Plus System) was conducted. The DNA present in the major component is consistent with originating from [the complainant]. The DNA present in the minor component is too weak and complex to determine the profiles of the individual contributors. [The respondent] could not be excluded as a minor contributor to this mixture. Additional DNA testing using the Y-filer System was conducted. DNA from at least two males was recovered. Assuming two males are present in the mixture and a male from the paternal line of [the complainant's father] is also present, then the profile of the second male contributor has been determined. [The respondent] cannot be excluded as the second male contributor. In addition, all male relatives on his paternal line and approximately 1 in 630 unrelated males in the general population cannot be excluded. ... 2bi Left hip area of shorts DNA testing using the Profiler Plus System was conducted. The DNA present in the major component is consistent with originating from [the complainant]. The DNA present in the minor component is too weak and complex to determine the profiles of the individual contributors. Additional DNA testing using the Y-filer System was conducted and recovered DNA from at least three male individuals. This profile is too complex to determine the profiles of the individual contributors." (emphasis added) 17Material tendered before his Honour indicated that the DAL undertook DNA analysis by a "PCR" (Polymerase Chain Reaction) method. This involves targeting specific areas of the DNA and copying or amplifying those targeted regions many millions of times. One common PCR procedure involves determining the size variation that exists at specific DNA sites due to short tandem repeats ("STR"). The "Profiler Plus" system referred to in the above report is the brand name of a particular DNA recognition system which utilises the STR procedure. According to his Honour "it is the system overwhelmingly used in New South Wales". It involves the targeting of what are described as "nine highly valuable areas of the DNA and one area determining gender". In her evidence on the voir dire Ms Franco explained that the Profiler Plus system examined nine different chromosomes. Nothing turns upon any difference in these descriptions (if there is any). 18The other method referred to in the above extract from the DAL report is the "Y-filer" system. It uses the same technology as the Profiler Plus system but only targets the Y chromosome in the gender pair of chromosomes. It is said to be useful when the DNA recovered is a mixture of both male and female DNA (as females do not possess a Y chromosome). An expert called by the defence on the voir dire, Professor Boettcher, stated as follows: "A way of envisaging the Y-filer system is to imagine the Y chromosome as a string of beads of different colours. In a group of men, each has a string of beads - but, the colours of the beads are in a different order for each of the men. Within the small group of unrelated men, no two have identical strings of beads. Some beads might be identical, but other beads on the strings will be different. In a large population, there may be two (or more) men who have identical strings of beads. When a man has a son, he copies his string of beads and gives each son an identical copy of his string of beads. The strings of beads are passed from generation to generation as whole strings, not on a bead by bead basis." 19Each of the two procedures can be used to exclude a person as a match. If two samples yield a "match" then it could mean that they are either the same individual or they match by chance. Both systems enable a statistical estimate to be made of the likelihood of a chance match. This is done by a comparison with a population database. However, there are significant differences between the statistical results commonly yielded by the two methods. 20Ms Franco explained that, with the Profiler Plus system, for each of the nine areas of DNA, a frequency of the occurrence of the result is obtained from the population database. These frequencies are multiplied and usually result in an extremely high statistical likelihood of the two samples being from the same person and a correspondingly low likelihood of a chance of identical DNA for two different people. This was described in the evidence as the "product method". 21With the Y-filer system there is only one area of DNA targeted, namely the Y chromosome. The population database is examined to determine the rate of frequency of the one characteristic that is identified. This was referred to in the voir dire as a "counting method" (see also Aytugrul v R [2010] NSWCCA 272; 205 A Crim R 157 at [144] to [146], per Simpson J). 22Ms Franco explained that the population database for the Y-filer results was comprised of 1889 people consisting of four major population groups, Aboriginal, Middle Eastern, European and Asian. There was no correspondence between the respondent's profile and any entry on the database. She explained that the result of taking a negative match with a sample of 1889 and using a 95% confidence interval, yielded the figure of 1 in 630 set out in her report. To this likelihood must be added all male relatives on the respondent's paternal lines to reflect the passing of identical Y chromosomes from father to son. Professor Boettcher did not disagree with that methodology but disputed the result of the calculation. He contended that the appropriate figure was 1 in 512.

The Voir Dire 23The matter was listed for trial on Wednesday 14 March 2012. The respondent had previously withdrawn his lawyers' instructions and only re-instructed them in the week prior to the trial commencing. His counsel was only engaged at the last minute. They accessed subpoenaed material from the Crown concerning the DAL test reports relied on by Ms Franco on the day before the trial was listed. It seems that Professor Boettcher was also only engaged just prior to the trial. He produced a short report on the day of the trial which made some useful comments but stated that he had not sufficient time to set out all of his concerns. Both Ms Franco and Professor Boettcher gave evidence before his Honour on 15 March 2012. His Honour handed down judgment on 19 March 2012. 24I have already described parts of the evidence from Ms Franco and Professor Boettcher given on the voir dire. It is necessary to briefly note four further points concerning the voir dire. 25First, Professor Boettcher was critical of that part of Ms Franco's evidence which concerned the results of the Profiler Plus system on area 2aii (the hip area of the underpants) and the respondent's DNA. Ms Franco's report stated the respondent "could not be excluded as a minor contributor" to the mixture of DNA found in that area, although she did not provide any accompanying statistical assessment. Professor Boettcher considered the data was "incoherent". I refer to this dispute below at [30] to [34]. 26Secondly, it is to be recalled that the Y-filer results for area 2aii were based on two assumptions. The first was that only two sets of male DNA were present; and the second was that one of those sets belonged to the complainant's father (see [16] above). In chief Ms Franco explained that the basis for the latter assumption was that it was "often ... the case that people in the family had DNA present on each other's clothes". Ms Franco did not provide any basis for the former assumption. Her report stated that DNA from "at least two males" were present and had identified DNA "from at least three male individuals" present in area 2bi (the hip area of the complainant's shorts). 27Third, Ms Franco was not cross-examined about either the validity of those assumptions or the effect of their potential invalidation on the conclusions in her report concerning the Y-filer results for area 2aii, eg if there was DNA from three males present on the hip area of the complainant's underpants did that make the Y chromosome "match" meaningless? How would her conclusions differ if she assumed that there were three contributors to area 2aii? Professor Boettcher did not address the significance of those assumptions either. 28Fourth, it was not submitted to his Honour that the unsafeness of the assumptions adopted by Ms Franco warranted the exclusion of the DNA evidence. Instead counsel for the respondent emphasised the prejudice to his client that would follow from the receipt of evidence suggesting that there was only a "1 in 500" to "1 in 600" chance that the probability of the Y chromosome match was only a co-incidence and not because the DNA on the complainant's underpants came from the respondent.

His Honour's Judgment 29In his judgment, his Honour described the Crown case and the evidence of Ms Franco concerning the use of the Profiler Plus system before summarising her evidence concerning the Y-filer system and its limitations. Two points should be noted about his Honour's recitation of this material. 30First, the Crown complains that his Honour misstated Ms Franco' evidence concerning the results of the Profiler Plus system when his Honour stated: "15 In her oral evidence Ms Franco acknowledged that the Profiler Plus system was unable to determine the profile of the minor contributors. Therefore, there was nothing for the Profiler Plus system to work upon to work out a statistical LR. In the absence of statistics from Profiler Plus she was unable to exclude the accused. Indeed, she was unable to offer any opinion one way or the other in respect of any of the nine DNA chromosome positions. She chose to go to another system and further testing in order, she says, to give some weight. We normally would not write, Cannot exclude without having some sort of statistic. 16 Frankly, that evidence is suspect. It is to be noted the DNA minor component inside the crotch of the underpants (2ai); the DNA minor component on the other hip area (2aiii); the DNA minor component of the left hip area of the shorts (2bi) and the DNA minor component on the right hip area, (2bi) have all been described as, "This profile is too complex to determine the profile of the individual contributor." Indeed, in respect of the right hip area, the material does not even appear to have been subjected to a Y-filer profile test." (emphasis added) 31The question and answer to which his Honour was referring to in [15] was the following: "Q. What is the reason that there's no statistic expressed there? [ie in her report concerning area 2aii and Profiler Plus] A. Because the profile of the minor contributors could not be determined, therefore there was nothing to - to actually work out a statistic. So all I'm saying is that, at each of the DNA - nine DNA positions, I couldn't exclude him but have gone on to do further testing in order to give some sort of weight. We normally would not write, 'Cannot exclude without having some sort of statistic.' " 32The Crown complains that his Honour has misunderstood Ms Franco as having written "cannot exclude" in circumstances where she was "unable to offer any opinion". It submits that she in fact stated there was enough data on the Profiler Plus system to allow her to form a limited opinion but not one to which she could attach any statistical significance (hence her reliance on the Y-filer system). Mr Stratton SC for the respondent pointed to the apparent contradiction in Ms Franco's report on area 2aii between, on the one hand, the statement that the DNA sample was too weak and complex to determine profiles and, on the other, the statement that the respondent could not be excluded as a minor contributor to the DNA mixture (see [16] above). He relied on Professor Boettcher's criticism of this aspect of Ms Franco's report that I have described above. In effect it was contended that his Honour's comments reflect the force of Professor Boettcher's criticism. 33I think there is considerable force in both sets of contentions. It seems to me that his Honour did misstate Ms Franco's evidence in this respect, although it is difficult to reconcile the statements that Mr Stratton SC pointed to. Further, it is difficult to see the utility for the Crown's case of a bare statement that a person cannot be excluded if it does not have any statistical significance attached to it. 34It is unnecessary for me to consider that further because, contrary to the Crown's submissions, I do not consider that any error on his Honour's part has any significance to his Honour's ultimate decision to exclude the DNA evidence. As I will explain it was the Y-filer results that were critical to that conclusion. If the results of the Y-filer analysis were excluded then, whatever be the correct analysis of Ms Franco's evidence concerning the Profiler Plus results (or lack of them), those results did not provide any assistance to the Crown case. 35Second, his Honour identified the difficulties with the Y-filer results flowing from the two assumptions set out in Ms Franco's report that I have referred to earlier. His Honour noted that the assumption that the complainant's father was one of the contributors was not supported by the Profiler Plus results and it was otherwise not so obvious that he would have contact with his daughter's clothing that it could be inferred without further evidence. The Profiler Plus results were neutral on the former issue and the latter criticism has some force. In addition, his Honour expressed concerns about the quality of DNA available for the Y-filer results and then noted the assumption that DNA from only two males was present on area 2aii was just that, namely an assumption and not a matter proved by Ms Franco. 36However, these matters did not ultimately inform his Honour's decision. Instead his Honour concluded: "36 ... In my view there is a real likelihood the probative value of this evidence is outweighed by unfair prejudice. The danger arises thus: 1 The Profiler Plus system overwhelmingly used in New South Wales and indeed used in this case was unable to separate out of the minor components nine DNA profiles matching the accused. The reason for this is the minor DNA component was too weak and complex to determine the profile of any individual. 2 It would seem the Profiler Plus results did reveal that the minor component was blended DNA. 3 It seems the Profiler Plus did not reveal the potential numbers of contributors to the minor component or their gender. 4 It seems the Profiler Plus was unable to catalogue the blend of the minor component into a dominant donor or a minor donor(s) of the DNA composing the minor component. 5 The Y-filer system's use so far as the DAL laboratories is concerned is focused upon its use as an excluder of DNA contribution. That is to say its forensic use is not from the DAL's perspective one dependent upon RL's [relative likelihood] of inclusion. 6 In this case the use of the Yfiler analysis has been harnessed for the purposes of matching a profile and determining (using a counting method) the RL of a donor being the crime stain donor. 7 The Y filer system focuses upon one chromosome only by contrast with the nine chromosomes relied upon by the Profiler Plus. 8 There is no uniqueness in the possession of the Y chromosome. All male relatives on the paternal line are highly likely to pass the same Y chromosome DNA profile in the absence of mutation. 9 The determination of the RL of such male relatives in the Westmead area known or unknown is a matter of speculation. What impact that has upon the RL figure be that figure 1 in 630 males or 1 in 512 males is hopelessly speculative. Indeed, the figures 1 in 630 or 1 in 512 may be misleading. Working on the RL figure of 1 in 630 that leaves open a potential of three and a half thousand males in the Sydney population of 4.5 million as having the same Y chromosome DNA profile. For each of those three and a half thousand males given that it is the Y chromosome that matches all male relatives on the paternal side of that match will also have the same Y chromosome. 10 It is likely the profile comparison from the crime stained DNA is an incomplete profile for comparison where 17 points of comparison is the norm. 11 There is criticism offered by Professor Boettcher in respect of comparisons of the heights of minor eliors [sic] at three loci sites. Professor Boettcher says there are, "Further comments to be made in the same vein" claiming that time did not permit him to make them given the speed with which the report was required. 37 Should all of the information that has been placed before me be conveyed to the jury and assuming it is understood by the jury, the probative value of the DNA evidence standing alone as a circumstance of identification would be verging on the unreliable and the meaningless. 38 The results of the Profiler Plus analysis were inconclusive. The accused was not excluded as a potential donor nor was the Profiler Plus able to match his DNA profile. The Y-filer results in the circumstances of this case may not be much better. 39 However, given the CSI effect, the time it would take to ventilate all this material in the evidence-in-chief, cross-examination and exhibits such as VD 3, 4 and 5, there is a real likelihood the jury would give far more weight to this evidence than it deserves. It would assume a weight equal to other pieces of identification evidence that are more capable of and have more cogency and stronger probative force." (emphasis added) (The reference to the "CSI effect" appears to be a reference to the risk that greater weight is attached to forensic evidence than is warranted: see Morgan v R [2011] NSWCCA 257 at [145] per Hidden J). 37His Honour excluded the evidence under s 137 (probative value outweighed by unfair prejudice), s 135(b) (misleading or confusing evidence) and s 137(c) (evidence might result in undue waste of time). His Honour relied on the latter provision after having assessed the likely time that the receipt and analysis of this evidence would occupy at the trial. 38Although three bases for exclusion were stated, they all have as their foundation his Honour's conclusion that the "probative value of the DNA evidence standing alone as a circumstance of identification would be verging on the unreliable and meaningless." In turn this conclusion was said to result from "all the information" listed in [36] of the judgment. With one exception, the points listed in [36] all concern the relative advantages of the Profiler Plus system compared with the Y-filer system (points 1 to 8 and 10) and the apparently speculative and misleading nature of frequency ratios in the range 1 in 512 to 1 in 630 (point 9). The one exception is the eleventh point in [36] of his Honour's judgment, which concerned a criticism of Ms Franco's report by Professor Boettcher. It is not clear whether his Honour accepted that criticism but it does not matter. Those comments of Professor Boettcher did not concern the Y-profiler results. Instead they were directed to debate about the Profiler Plus results that I have already discussed (see [25] and [30] to [34] above).

Aytugrul v R [2012] HCA 15 39In Aytugrul the appellant was charged with murder. He was accused of stabbing the deceased. Expert evidence was adduced at his trial that he had a particular DNA profile (a mitochondrial haplotype) and that the same haplotype was detected in a hair found under the nail of the deceased. The expert stated the mitochondrial sequence identified in the hair sample had not been observed in any of the 4839 individuals listed on the relevant population database (Aytugrul v R [2012] HCA 15; 86 ALJR 474 at [9]). Using a similar approach to that adopted in this case, this translated to a frequency ratio of 1 in 1600 persons as being expected to have the same DNA profile as that of the appellant. This translated to 99.9% of the population being excluded (an "exclusion percentage"). 40At trial objection was taken to the evidence of the expert extrapolating from the comparison with the database to expressing either a frequency ratio or an exclusive percentage (at [10]). The objection was overruled. On appeal to this Court, the appellant argued, inter alia, that a miscarriage of justice was occasioned by the use of the exclusion percentage as opposed to the frequency ratio even though one was a mathematical mirror image of the other. By a majority this contention was rejected by this Court (Aytugrul v R [2010] NSWCCA 272; 205 A Crim R 157 at [198], per Simpson J, at [238], per Fullerton J contra McClellan CJ at CL at [99]). It was further rejected on appeal to the High Court (Aytugrul v R [2012] HCA 15; ALJR 474). 41In both this Court and the High Court it was contended that "evidence" of the exclusion percentages should have been rejected under s 135 and s 137 as being misleading or prejudicial. This contention was framed at a level of generality that suggested that in every case an exclusion percentage should be rejected because its probative value is always outweighed by the degree of unfair prejudice occasioned by it being admitted ([2012] HCA 15; ALJR 474 at [19] - [20], per French CJ, Hayne, Crennan and Bell JJ). The plurality judgment (French CJ, Hayne, Crennan and Bell JJ) rejected this contention: "30. The unfair prejudice said to arise in this case was alleged to flow from the use of a percentage figure, which carried a 'residual risk of unfairness deriving from the subliminal impact of the raw percentage figures' by way of rounding up the percentage figure to 100. If the exclusion percentage were to be examined in isolation, the appellant's arguments appear to take on some force. But to carry out the relevant inquiry in that way would be erroneous. In this case, both the frequency ratio and the manner in which the exclusion percentage had been derived from the frequency ratio were to be explained in evidence to the jury. The risk of unfair prejudice - described by the appellant as the jury giving the exclusion percentage 'more weight ... than it deserved' - was all but eliminated by the explanation. It is not right, as the submissions of the appellant implicitly urged, and as appears to have been the approach taken in R v GK, to assess the danger of unfair prejudice by reference only to the exclusion percentage, ignoring all other evidence. In assessing the danger of unfair prejudice to a defendant, regard must be had to the whole of the evidence that is to be given, particularly by the witness to whose evidence objection is taken. When that is done in this case, recognising, in particular, the evidence that it was proposed to lead from the witness about the derivation of the exclusion percentage, there was no danger of unfair prejudice that required rejection of the exclusion percentage. ... 32. There may be cases where evidence given of exclusion percentages may warrant close consideration of the application of s 135 or s 137 (or, where applicable, equivalent common law doctrines or statutory provisions). These reasons are not to be read as suggesting to the contrary. Evidence given about the results of DNA analysis is evidence about comparisons between identified samples and one or more databases. The results of those comparisons can be expressed qualitatively or quantitatively. If expressed quantitatively there are assumptions and approximations made which often (perhaps always) require elucidation and explanation to make plain what are the limits to the opinion that is being expressed as a number or range of numbers. Just as evidence of an opinion given by an expert must, in order to satisfy the requirements of admissibility in s 79(1) of the Evidence Act, be "presented in a form which makes it possible to answer" the question posed by that provision, it will usually be important, even necessary, that the evidence provides the jury with so much of the expert's "specialised knowledge" as the jury requires properly to understand the opinion expressed - and what it can and cannot demonstrate - and that this specialised knowledge be related to the facts of the case. ... 34. In this case, where both the frequency ratio and the exclusion percentage were given, and the relationship of one to the other was explained, there was neither a wrong decision of any question of law nor on any other ground a miscarriage of justice." (citations omitted) 42These passages emphasise that a consideration of the entirety of the evidence to be relied on is required in determining whether a particular piece of evidence is prejudicial. In Aytugrul, the evidence of exclusive percentages was accompanied by a frequency ratio as well as by explanations as to how they were derived and what they meant. None of that evidence was found to be either misleading or inaccurate or as having the capacity to mislead the jury (see also Heydon J at [75] - [77]).

Consideration 43The High Court's decision in Aytugrul was not handed down until after his Honour's judgment. However, his Honour was referred to the judgment of this Court in Aytugrul "as supportive for the proposition that [a ratio likelihood, ie frequency ratios] in the low thousands is admissible for the purpose of identification". His Honour distinguished this Court's decision in Aytugrul on two bases. First, his Honour noted that Aytugrul was not a case where ss 135 or 137 of the Evidence Act were relied on at trial. Secondly his Honour noted that the DNA profile considered in Aytugrul did not have the "concerns" that Ms Franco had identified with the samples in this case. 44It follows from the above that I consider there is force in this second basis but it did not ultimately inform his Honour's decision to exclude the DNA evidence. However, with respect to his Honour, the first basis was not a proper reason for distinguishing the decision of this Court in Aytugrul. While ss 135 and 137 were not relied on and considered at trial in Aytugrul, they were relied on and considered in this Court (see [2010] NSWCCA 272; 205 A Crim R 157 at [171] to [172], [194] and [198], per Simpson J) and that consideration was binding on his Honour. In any event the matter is now to be considered in light of the High Court's judgment in Aytugrul. 45I have extracted and summarised the critical part of his Honour's reasons for excluding the DNA evidence above. One aspect of his Honour's assessment of the evidence as "verging on the unreliable and the meaningless" was that it was of less rigour than the results from the Profiler Plus system in the sense of producing lower frequency ratios. This may be the case but that does not render it unreliable or meaningless, much less identify "prejudice" for the purposes of s 137 or make it "misleading" for the purpose of s 135. 46Ultimately what was critical to his Honour's decision was the conclusion in point 9 of paragraph [36] of his Honour's judgment (extracted in [36] above) that frequency ratios in the order of 1 in 512 or 1 in 630 are "hopelessly speculative" or "misleading". His Honour said that they leave open a "potential of three and a half thousand males in the Sydney population of 4.5 million as having the same Y chromosome DNA profile". This calculation may be correct but that does not make the ratio "hopelessly speculative" or "misleading" especially if it was accompanied by an explanation from Ms Franco as to how she arrived at that figure and what it meant. Leaving aside the assumptions to which I have referred, Ms Franco's report suggests that a particular Y chromosome is a characteristic shared by the respondent and a person who has been in contact with the complainant's underpants. In one sense this characteristic is conceptually no different to the cheek piercings and jewellery that are common to the respondent and the offender as identified by the complainant and the young boy witness. They all form part of a matrix of facts from which the jury might, but not necessarily would, draw a conclusion adverse to the respondent to the appropriate standard. 47The difference between the piercings and the Y chromosome is that with the former the jury can make their own common sense assessment of the frequency of occurrence of such a feature. They cannot do the same with a common Y chromosome. To assist them in that task a straightforward, precise and accurate expert explanation is required which can include frequency ratios and exclusion percentages. His Honour considered that the danger of figures in the form of frequency ratios carried with it too much risk of a misunderstanding by the jury. Hence his Honour later stated that the "witness box is not a classroom" and that, based on his Honour's experience, "it is unlikely a jury hearing evidence of DNA issues in this case would retire to the jury room with an accurate précis of the evidence in their minds." His Honour's experience in this area is considerable. However, with respect to his Honour, this reasoning is inconsistent with the High Court's judgment in AytugruI. The judgment in Aytugrul rejected the suggestion that an exclusion percentage was necessarily prejudicial, finding that it could be and was the subject of an accurate explanation to the jury which they were capable of understanding ([2012] HCA 15; 86 ALJR 474 at [30] and [75]). Those observations apply with even greater force to a frequency ratio. 48In my view, his Honour's finding in this case that the "probative value of the DNA evidence standing alone as a circumstance of identification would be verging on the unreliable and the meaningless" was erroneous. It follows from the High Court's judgment in Aytugrul that, provided it was properly and clearly explained, DNA evidence of the kind considered here could be of assistance to, and understood, by the jury. For the same reasons the prejudice his Honour identified for the purposes of s 137 of the Evidence Act also does not survive the judgment in Aytugrul. These conclusions are more than sufficient to vitiate his Honour's rejection of the evidence under s 137. Further, they have the consequence that the exercise of his Honour's discretion under s 135 miscarried. In concluding that the DNA evidence would be "misleading" because of the frequency ratio and that its admission would cause an "undue" waste of time, his Honour acted on both a "wrong principle" and a mistake as to the facts (House v The King (1936) 55 CLR 499, at 504 - 505). 49In seeking to resist the appeal Mr Stratton SC made a number of powerful submissions concerning the effect of Professor Boettcher's evidence and the validity of the assumptions made by Ms Franco. I have already referred to those matters and I refer to them further below. The difficulty is that, although his Honour referred to those issues in his judgment, they did not ultimately play any significant part in his Honour's decision to reject the DNA evidence. The extract I have set out above makes it clear that his Honour had a fundamental objection to the admission of frequency ratios of the kind yielded by the Y-filer analysis. This reflected the manner in which the matter was argued. It follows from Aytugrul that that objection had no proper basis in principle. 50It may be a basis for resisting a Crown appeal under s 5F(3A) that the respondent can demonstrate that, even if the trial judge's reasoning was flawed, the evidence in question still should have been rejected. This would be a difficult threshold to meet in the case of a discretionary decision to exclude evidence. Although, as I have said, a number of doubts were raised about the evidence other than the relatively low frequency ratio, I am not satisfied that the evidence must have been rejected in any event. No doubt due to the late preparation and the focus on the frequency ratio these doubts were not fully explored during the voir dire. 51For the Crown to succeed on an appeal under s 5F(3A) the Court must be satisfied that the decision or ruling "eliminates or substantially weakens the prosecution case". This is to be determined on the assumption that the jury accepted the evidence and without any investigation into the weight of the evidence based on any credibility or reliability considerations (R v Shamouil [2006] NSWCCA 112; 66 NSWLR 228 at [40], per Spigelman CJ). The rejection of the DNA evidence that I have described removed an important plank of a circumstantial Crown case on identification. I am satisfied that it substantially weakened the prosecution case.

Further challenges 52It follows that I consider that the appeal should be allowed and that his Honour's rejection of the DNA evidence should be set aside. As should be otherwise obvious, nothing in this judgment is meant to preclude any reconsideration of the admissibility of the DNA evidence in this case, especially when Professor Boettcher has had the opportunity to provide a more considered report. 53Further, and without limiting the scope for further challenge, it may be that either or both of the two assumptions adopted by Ms Franco cannot be supported. It also may be that the Y-filer results are meaningless if either or both are not established. If that were the case there would be considerable room for doubt as to whether the DNA evidence met the threshold for admissibility in s 55 of the Evidence Act even before any consideration need be given to its rejection under ss 135 or 137. 54The orders I propose are: (1)Appeal allowed. (2)The judgment of Judge Nicholson SC, dated 19 March 2012, be set aside. DISCLAIMER - Every effort has been made to comply with suppression orders or statutory provisions prohibiting publication that may apply to this judgment or decision. The onus remains on any person using material in the judgment or decision to ensure that the intended use of that material does not breach any such order or provision. Further enquiries may be directed to the Registry of the Court or Tribunal in which it was generated. Decision last updated: 01 March 2013