Expert evidence on forensic techniques is regularly presented in criminal trials. Forensic results can potentially decide the outcome of a criminal trial. In order to achieve a just result, it is essential that the results are reliable, and that the evidence is presented in a manner which allows the decision-maker to properly assess its significance. The US decision of Daubert v Merrell Dow Pharmaceuticals Inc. outlines a number of scientific principles which should be considered when assessing the reliability of expert evidence. Australian case law has no equivalent set of criteria, but expert evidence must be reliable to be admitted. This study examines whether the reliability of two commonly used forensic techniques, namely fingerprints and DNA, is adequately tested within the adversarial system. I reviewed 20 transcripts of fingerprint evidence and 20 transcripts of DNA evidence in criminal trials in Western Australia in order to investigate how lawyers approach these two areas of expert evidence, i.e. what areas they tend to canvass during examination-in-chief and cross-examination. Part A outlines the case law in Australia and the US in relation to expert evidence, and the main scientific principles. Part B discusses the techniques of fingerprint analysis and DNA analysis, including potential difficulties associated with the two techniques, as well as the results of the analysis of the trial transcripts. The result of the analysis shows that lawyers focus on the result of the analysis, whereas the reliability of the method which the findings are based on is subject to little scrutiny. This is particularly so in the area of fingerprint evidence.
|Publication status||Unpublished - 2011|