Some notes on Preventing Miscarriages of Justice: The Reliability of Forensic Evidence and the Role of the Trial Judge as Gatekeeper

I recently read Justice Chris Maxwell’s Preventing Miscarriages of Justice: The Reliability of Forensic Evidence and the Role of the Trial Judge as Gatekeeper. That links goes to a talk he gave with the same title and some of the same content. The actual article was published in the Australia Law Journal in 2019, but there doesn’t seem to be a free version of it out there. Contact me if you’d like a copy.

Justice Maxwell is one of few Australian judges to write about the reliability of expert evidence. In his decision in R v Tuite, he held that reliability of scientific expert evidence should be assessed as part of the evidence’s probative value, and that inquiry should be guided by the concept of scientific validity. This seemed to be overruled in R v IMM. In that case, the majority said trial judges should not consider reliability when assessing probative value.

In the present article, Justice Maxwell provides a useful review of forensic science and the fact that for many practices, reliability is unknown. Further, such practices have contributed to many wrongful convictions in Australia and abroad.

Particularly relevant to the the decision in IMM, Maxwell writes:

Third, and self-evidently, jurors are in no position to assess the reliability either of the scientific foundation on which an expert’s opinion rests or of the methodology adopted to arrive at the opinion. The PCAST Report made the point emphatically: The vast majority of jurors have no independent ability to interpret the probative value of results based on the detection, comparison, and frequency of scientific evidence. … The potential prejudicial impact is unusually high, because jurors are likely to overestimate the probative value of a ‘match’ between samples

Justice Maxwell goes on to discuss several possible responses Australia can take. These include (1) changing the rules of evidence to consider reliability (e.g., as part of the definition of specialized knowledge in s 79); (2) asking lawyers and judges to be more vigilant; (3) reforming procedures as Victoria recently did, and; (4) developing some sort of scientific evidence advisory group or national forensic science regulator.

Overall, there’s not much new here, but it is very nice to see an Australian judge taking forensic science seriously.