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).