Improving the use of DNA evidence at trial

44.33 DNA technology is an evolving area of science. Different methods of DNA analysis and statistical calculation may be employed by forensic scientists who will then be required to give evidence about these methods and results in criminal proceedings. DP 66 noted that a number of proposals may be necessary to ensure that DNA evidence is used in criminal proceedings in a way that is fair and upholds the ethical standards expected in the use of genetic information. These proposals relate primarily to the presentation of the evidence, and improving the level of understanding of DNA science and evidence by each participant in criminal proceedings.^[33]

Educating the legal profession

44.34 The way in which DNA evidence is presented in criminal proceedings can be fundamental to the outcome of the proceedings, due to the scientific nature of the evidence and the characteristically large numbers used to estimate the probative value of a DNA match.

44.35 In order to evaluate DNA evidence properly, the jury must have sufficient understanding of DNA analysis and the statistical calculations used to determine its probative value. In most cases, it is the role of the expert scientific witness to explain the science and technology of DNA analysis, the interpretation of the results, and their significance to the jury.^[34] However, the prosecution and defence counsel must also have sufficient understanding to examine or cross-examine the expert witnesses appropriately. The trial judge must have sufficient understanding to properly direct the jury in its evaluation of the evidence.

Submissions and consultations

44.36 DP 66 proposed that the National Judicial College of Australia and the Law Council of Australia (through its constituent professional associations) should ensure the availability of continuing legal education programs for judges and legal practitioners, respectively, in relation to DNA evidence.^[35] Most of the submissions supported the proposal.^[36] The Law Institute of Victoria ‘strongly endorsed’ the proposal, noting that:

The National Judicial College of Australia and the Law Council of Australia would be appropriate bodies to fulfil this role … ongoing training is absolutely essential in such a fast‑moving and developing area, where training and skills can become redundant very quickly with potentially catastrophic results for the individuals involved.^[37]

44.37 Dr Barbara Hocking of the Queensland University of Technology, expressed support, commenting that:

The questioning of experts undoubtedly influences the knowledge gained by the jury of the science that the expert represents in court. These complex scientific issues are translated to the judge and jury through the lawyers and where they are scientifically ill-equipped they cannot by definition fully illuminate the area for those parties. Cross-examination is intended to elicit all relevant information but only knowledge of scientifically acceptable procedures and scientific methodology and reasoning will fully equip lawyers in these situations to adequately inform the jury …^[38]

44.38 Dr Hocking also recommended that university law programs be expanded to include scientific disciplines.^[39]

44.39 Wendy Abraham QC, the South Australian Associate Director of Public Prosecutions, told the Inquiry that in criminal proceedings involving DNA evidence the prosecutor must have a good understanding of probabilities so that the jury can be properly led. She noted that education is important and agreed that the nominated organisations would be appropriate to provide such legal education.^[40]

44.40 Several submissions suggested that the Human Genetics Commission of Australia (HGCA) should be involved in facilitating genetic education for these professional groups.^[41] The Human Genetics Society of Australasia emphasised the importance for the proposed bodies to liaise with established genetic education bodies in providing education to these groups:

In order to ensure that the legal profession are appropriately skilled to understand DNA evidence it is important that continuing education is provided to them. It will be important for liaison with the HGSA and other genetics education organisations to ensure that National Judicial College of Australia and the Law Council of Australia access experts from the medical and scientific community to maintain the highest possible standards in this education.^[42]

Inquiry’s views

44.41 The Inquiry considers there is a need for greater education in DNA science and evidence among scientific and legal professionals and the judiciary. For example, in R v Keir the ‘prosecutor’s fallacy’ was committed by the prosecution and repeated by the trial judge, but was not corrected by the defence counsel. If the conviction had not been appealed, the ‘fallacy’ might not have become known and might have been continued in future criminal proceedings.

44.42 The proposal was supported by most of the submissions, and was consistent with the Australian Law Reform Commission’s recommendations in the Managing Justice report, which called for enhanced professional development and continuing education schemes in order to improve the efficiency and effectiveness of the justice system. In particular, the Commission called for greater emphasis on programs for trial lawyers and judges, to familiarise them with DNA science, technology and evidence.^[43]

44.43 Several submissions suggested that the HGCA should play a role in the provision of education to judges and legal practitioners about DNA evidence. As discussed in Chapter 5, the Inquiry intends the HGCA to play a major role in public and professional education. In many cases this will involve assisting or facilitating other bodies in providing the direct educational and training services. The Inquiry suggests that, where requested by the National Judicial College of Australia and the Law Council of Australia to do so, the HGCA should provide guidance in developing these continuing legal education programs.

44.44 The Inquiry also considers that expanding the curriculum in both undergraduate and postgraduate university law programs should be encouraged. For example, some law schools could include elective subjects in the scientific and evidential issues relating to DNA evidence.

44.45 The Inquiry recommends that the National Judicial College of Australia and the Law Council of Australia (through its constituent professional associations) should develop and promote continuing legal education programs for judges and legal practitioners, respectively, in relation to the use of genetic information in criminal proceedings.

Improving jury understanding

44.46 While defence counsel has the opportunity to test the probative value of evidence through cross examination of an expert witness, the jury might nonetheless be ‘dazzled’ by the statistics presented to them, and fail to consider the DNA evidence in the context of all the other evidence admitted. In addition, a jury might introduce the ‘prosecutor’s fallacy’ even though the evidence is presented and summed up correctly.

44.47 Some commentators have suggested that some descriptions of DNA match statistics may have a larger impact on jurors than others because

the perceived probative value of a statistical DNA match (and, by extension, other forensic match evidence) depends on the ease with which triers of fact can imagine examples of others who would also match the DNA profile. When triers of fact find it hard to imagine examples of others who might match by chance, the evidence will be treated as compelling proof that the matching suspect is the source of the recovered DNA evidence. But when such matches are easier to image, the evidence will seem less compelling.^[44]

44.48 The National Institute of Forensic Science and the Australian Institute of Judicial Administration are currently conducting a research project into jury comprehension of DNA evidence. This project should lead in future to more effective communication of DNA evidence and better understanding by juries.^[45]

Options for reform

44.49 There are several possible ways to improve jury understanding about the nature of DNA evidence to ensure they are able to properly evaluate the probative value of the evidence. Juries could be given written guidance in the form of booklets that explain DNA evidence generally, for reference during the trial.^[46] For example, Wendy Abraham QC advised the Inquiry that she has used jury books to assist jury members in relation to DNA evidence. The books contain a range of material including a glossary of terms, diagrams of processes, photos of testing equipment, tables of results and so on to assist the jury.^[47] Alternatively, Professor Ron Trent suggested that a standard educational video about DNA technology could be shown to juries before the trial, and replayed for them later, if required.^[48]

44.50 Courts could formulate guidelines for the presentation of DNA evidence. The English Court of Appeal formulated guidelines in the headnote to its judgment in R v Doheny & Adams. The guidelines deal with the presentation of DNA statistical evidence to the jury; procedural issues such as service of DNA evidence on the defence and the identification of issues of expert evidence before trial; and judicial instructions about the summing up.^[49] The Northern Territory Court of Appeal formulated a similar set of guidelines in its judgment in Latcha v R.^[50] The Supreme Court of British Columbia has formulated the following guideline:

[I]t can be made sufficiently clear to the jury that: 1) the estimates are not intended to be precise; 2) they are the products of mathematical and scientific theory, not concrete facts; 3) they do not purport to define the likelihood of guilt; 4) they should only be used to form a notion of the rarity of the genetic profile of the accused; and 5) the DNA evidence must be considered along with all the other evidence in the case relating to the issue of identification.^[51]

44.51 A third possibility is the development of a standard judicial direction to juries for use either (a) where requested by the defence; or (b) in all cases in which a party to criminal proceedings seeks to rely on DNA evidence.

44.52 Section 165 of the Evidence Act 1995 (Cth) (Evidence Act) provides for judicial warnings to the jury in relation to evidence of a kind that may be unreliable, including identification evidence. Where a party requests the judge to do so—and unless there are good reasons not to do so—the judge must warn the jury that the evidence may be unreliable; inform the jury of matters that may cause it to be unreliable; and warn the jury of the need for caution in determining whether to accept the evidence and the weight to be given to it.

44.53 Defence counsel currently would need to request a judicial warning under s 165 where they consider that, in the circumstances of a particular case, the DNA evidence is unreliable. Where the defence counsel failed to request the direction, or where the judge determines the evidence is not unreliable, the direction would not be given.

44.54 An alternative approach would be to insert a standard jury direction regarding DNA evidence into the Evidence Act. The standard direction would provide that the trial judge must direct the jury on the need for caution in evaluating DNA evidence and the statistical calculations relating to that evidence either in all cases, or where considered appropriate. This approach recognises that DNA evidence is a form of scientific evidence that may, without proper direction, be given more probative weight by a jury than is warranted, and ensures consistency in the judicial approach to DNA evidence in criminal proceedings.

44.55 Matthew Goode commented on the desirability of jury directions in relation to DNA evidence:

The highly subjective nature of the mathematical processes remains concealed behind the apparent certainty of a bald statistic. It may also be that the larger the number of loci compared, the higher the statistic, the more need there is for an appropriate direction to the jury about what the really impressive statistic really means.^[52]

44.56 Goode emphasised the need to formulate more specific jury directions about the subjective nature of the match probability statistic; the factoring in of the incalculable but real possibilities of laboratory error, depending upon the accreditation and practices of the laboratory concerned; and the limitations on the use of certain types of calculations to produce the statistical result.^[53]

44.57 South Australia’s Court of Criminal Appeal recently rejected the submission that a general warning should always be required in relation to statistical DNA evidence. While there might be cases where particular circumstances call for a special direction or warning, the Court considered this would depend on the particular facts and circumstances in any given case.^[54] Chief Justice Doyle commented that:

it is undesirable to impose on trial judges the obligation, as a matter of law, to give warnings to a jury except when that is truly necessary. Any idea that there is no harm in giving a warning, and therefore that it is appropriate to make the warning obligatory, should be rejected. Each warning adds to the length of a summing up, and to the matters that a jury must consider. And there is a danger that the giving of too many warnings will undermine the impact of those warnings that are truly required, or will distract the jury from a straightforward consideration of the material before them.

As long as the judge explains to the jury how the evidence may be used, and how it should not be used, there is no need for warnings against its misuse generally, or for a warning against misuses of the evidence that have not taken place in the trial.^[55]

Submissions and consultations

44.58 DP 66 proposed that a standard jury direction should be inserted into the Evidence Act for use where DNA evidence has been admitted in criminal proceedings. The Inquiry noted that the direction should outline the warning that a trial judge should give the jury regarding the need for caution in evaluating DNA evidence and the statistical calculations relating to that evidence.^[56]

44.59 Most of the submissions supported the proposal.^[57] The Law Institute of Victoria commented that:

The Law Institute supports the introduction of a standard jury direction, to be inserted into the Evidence Act 1995 (Cth) for use where DNA evidence has been admitted in criminal proceedings. The direction should outline the warning that a trial judge should give the jury regarding the need for caution in evaluating DNA evidence and the statistical calculations relating to that evidence. We believe this is essential in a climate where scientific evidence, and DNA evidence in particular, is often accorded more weight and probative value by the average layperson than is appropriate.^[58]

44.60 The South Australian Attorney-General’s Department supported a mandatory jury direction, noting that ‘making it up on the spot’ can lead to appeals against con-viction.^[59] By contrast, Wendy Abraham QC did not agree with the giving of warnings as a matter of course because, in her view, DNA evidence is not inherently unreliable. She commented that judges are generally disinclined to use standard directions.^[60]

44.61 Several submissions emphasised the need for flexibility in the form of words used in each case, as did several consultation meetings.^[61] For example, the Victorian Bar commented that:

The Victorian Bar agrees that trial judges should be required in all cases to warn the jury with respect to DNA evidence. However, rather than enshrining a set formula for the direction within the legislation, it would be preferable to include a ‘checklist’ indicating the minimum requirements to be included in such a direction. The legislation should emphasise the need to structure the direction to suit the facts and issues in any given case.^[62]

44.62 Liberty Victoria noted that appeal courts develop directions over time and these directions take the form of words that are flexible enough to deal with particular situations. It would be difficult for Parliament to develop a direction that would apply to all possible circumstances—and this would be better done through the courts.^[63]

44.63 Finally, the Centre for Genetics Education submitted that the HGCA could be involved in the development of resources for juries to enable understanding of the DNA evidence.^[64]

Inquiry’s views

44.64 The submissions generally supported the proposal for a standard jury direction but differed in relation to the circumstances in which the direction should be given, and the form the direction should take. Some submissions suggested that the direction should be given only in cases in which the evidence suggests the jury might misunderstand the evidence; others considered that DNA evidence is inherently difficult for juries to understand and the direction should accordingly be given in all cases in which the evidence is admitted. At the same time, some submissions supported a specific direction while others suggested that the trial judge should have some flexibility in its formulation.

44.65 The Inquiry considers that unless the trial judge considers it would be unreasonable in the circumstances of the case to do so, the judge should provide a direction to the jury in all criminal proceedings in which DNA evidence is admitted. This would help ensure that the jury is not confused by, or unduly impressed with, the statistical calculations when evaluating the evidence.

44.66 The Inquiry now considers that it would be more appropriate for a standard direction to be formulated by the judiciary. Therefore, in each jurisdiction a body representing the judiciary should develop a model direction. The model should provide guidance to trial judges in cases in which DNA evidence has been admitted, but should provide sufficient flexibility to be adapted to the circumstances of a particular case. The judicial body in each jurisdiction would differ. For example, in federal juris-diction, the National Judicial College of Australia might develop the model direction; in New South Wales, the New South Wales Judicial Commission might do so.

Managing the use of DNA evidence

44.67 The Inquiry recognises that there is ongoing debate within the field of forensic science about the appropriate means of calculating and presenting DNA evidence in court proceedings. In DP 66, the Inquiry commented that some form of independent standard setting should be provided regarding the use of DNA evidence in criminal proceedings.^[65]

44.68 The New South Wales Legislative Council Standing Committee on Law and Justice recognised the importance of such standard setting in its review of the NSW forensic procedures legislation. The Committee noted that the New South Wales government had proposed the establishment of a State Institute of Forensic Sciences (SIFS) to oversee the organisation and management of forensic sciences and the use of technology in criminal investigations and prosecutions.^[66] The Committee recommended that priority attention be given to the establishment of the SIFS to manage the use of technology in criminal investigations and prosecutions, and that it be requested to further examine methods of calculating the significance of DNA matches.^[67]

44.69 The National Institute of Forensic Science (NIFS) is an existing body with similar functions. NIFS was established under an agreement signed by the Australasian Police Ministers’ Council (APMC) in 1991. NIFS is a national body that reports to the APMC, and its board of control comprises three Commissioners of Police and three forensic laboratory directors. The current chair is the Chief Justice of Victoria.^[68]

44.70 NIFS’ core functions require it to sponsor and support research in forensic science; advise on and assist with the development and co-ordination of forensic science services; gather and exchange forensic information, including through the establishment of a national forensic reference service; support, co-ordinate and conduct training programs in forensic science; and conduct relevant quality assurance programs. It is also charged with raising the profile of forensic science.^[69]

Submissions and consultations

44.71 In DP 66, the Inquiry proposed that a body with expertise in forensic science and court proceedings should provide ongoing guidance to forensic scientists and legal practitioners regarding reliable methods of DNA analysis, statistical calculation, and presentation of evidence in criminal proceedings. As NIFS already fulfils these functions, the Inquiry suggested that this would be an appropriate body to take on this role.^[70]

44.72 The Inquiry received few responses in respect of this proposal. Those submissions that addressed the issue generally expressed support.^[71] Wendy Abraham QC also expressed support in a consultation meeting.^[72] The Law Institute of Victoria commented that it:

generally supports a proposal for provision of ongoing guidance to forensic scientists and legal practitioners regarding reliable methods of DNA analysis, statistical calculation, and presentation of evidence in criminal proceedings … However we are concerned that this proposal … refers only to guidance from one body, the National Institute of Forensic Science. Given the enormous debate surrounding appropriate use of DNA testing and the weight and credibility to be given to samples dependant upon a myriad of conditions, we believe that wider consultation and guidance may be appropriate, from a range of suitably screened bodies.^[73]

44.73 The Victoria Police similarly commented that the proposal should also

incorporate the jurisdictions providing advice in addition to NIFS. This could be coordinated through the Specialist Advisory Groups, which provide high level advice on policy issues relating to biological casework including DNA.^[74]

Inquiry’s views

44.74 There is a clear need for a body to oversee the use of technology in criminal investigations and prosecutions, and the Inquiry recognises that NIFS already conducts these activities. The Inquiry’s only concern is that NIFS has been established within the law enforcement community, being subject to the direction of APMC. This may lead to a possible perception that NIFS is a ‘police’ body—however, the Inquiry has not heard any complaints of this nature.

44.75 The Inquiry recognises that, in practice, it is unlikely the Commonwealth government would establish another forensic science institute to oversee the use of technology in criminal investigations and prosecutions. Therefore, the Inquiry recommends that NIFS, in consultation with members of the criminal justice and science communities (including defence practitioners and forensic scientists conducting defence work), should provide ongoing guidance to forensic scientists and legal practitioners regarding reliable methods of DNA analysis, statistical calculation, and presentation of evidence in criminal proceedings.