The complicated relationship between the disciplines of law and science is never so openly on display as it is in the study of fact-finding in evidence law. What evidence is allowed in a trial, how it has been collected and summarised, what weight it is given, and how its reliability plays on the minds of a jury are all issues at the crossroads of scientific method and legal reasoning.
In this respect, it was fitting that High Court Justice The Hon Stephen Gageler AC gave a keynote address titled ‘The Science of Truth’ to the conference jointly held by the National Judicial College of Australia and the ANU College of Law, Brave New Worlds: Challenges for Evidence in the 21st Century. On March 4th and 5th, 2017, Brave New Worlds brought together some of Australia’s sharpest academic and judicial minds to address some of the deeply challenging issues that evidence law faces in a modern world of science and technology.
A sample of some of the contentious issues raised are noted here. The first was how transcripts of covert recordings are used in court and how they can be unreliable and contain difficult-to-detect inaccuracies, which risks likely injustice unless independent phonetic science is more prominently featured in the court process. Another related classic example is in the use of less-than-certain DNA evidence, and the issues around the so-called “CSI effect” where juries are susceptible to trusting any forensic evidence as fact. Perhaps more worrying, research around face identification of strangers suggests that even under the best of conditions, our ability to correctly ID unknown faces is as low as 50%, worsening with other-race effects, despite the weight that such evidence carries in court. These sessions were filled with difficult questions that clearly did not have easy answers.
These apparently severe conflicts between research and evidence law can, in my mind, be attributed to two key differences between scientific and legal practice. In science, a publishable theory or method is measured against all existing theories by a high threshold of statistical significance, and its purpose is to improve upon our estimation of facts without making claims of certainty. In law, an admissible theory or method is measured against the legal standard (beyond reasonable doubt or balance of probabilities) in isolation, and is for the purpose of proving facts and subsequently treating them as if they were certain. Science can be published with error bars, confidence intervals, and recommendations for future research developments. Judgments cannot.
A scientific method which is accurate 95% of the time will be rendered obsolete by an otherwise similar method which is accurate 99.5% of the time. The same 95% accurate method, however, might be the only one used for forensic evidence adduced by a prosecutor, and the existence of the other method may no longer be relevant. If a judge threw out relevant key forensic evidence simply because it used an outdated method which was slightly less accurate than possible, then an otherwise strong case could be substantially weakened. What is publishable in scientific journals and what is admissible in court are two deeply different measures.
On one hand, this allows the court system to function efficiently, to hear useful evidence and to get results. If research methods were only allowed if they had been published in respectable academic journals, and expert witnesses were only called if they had the right accreditation by professional bodies, then hearings and trials with contentious evidence issues would rise in costs and would slow down badly.
On the other hand, however, worse than justice delivered slowly, is justice delivered wrongly. The admission of questionable expert witnesses with little or no real expertise, evidence using second-rate identification or transcription methods, or testimonies of eyewitnesses whose identification abilities in similar controlled circumstances are a coin-toss, all of which will be given significant weight by a jury or even a judge without a scientific background, is dangerous.
This appears to lead us to a defeated conclusion: that fact finding in law is, and always will be, less reliable than fact finding in science. Evidence law will not always have the luxury of being scientifically publishable. This truth, however, once accepted, is helpful. Science and law are not enemies and their relationship should not be given up on. Twenty-first century science can be applied to help us understand the justice system in ways never before available to us. Because science and law give different types of insights, they can collaborate fruitfully, and with this sentiment, I refer back to Justice Gageler’s address to Brave New Worlds.
In speaking about the ‘Science of Truth’, Justice Gageler was suggesting how behavioural science does indeed show that we are much worse at forming subjective beliefs about facts under conditions of uncertainty. Reference was made to Professor Daniel Kahneman, and as a student of psychology, I highly recommend his work. We are worse at estimating probabilities than we think. We are less rational than we think. Our thought processes are affected by serious and persistent biases. But this does not mean that we give up on having juries or judges or finding facts. Similarly, we do not give up on forensic or expert evidence because it is imperfect.
Science has a role to play in informing the legal process, and that role is expanding in the 21st century world. If we acknowledge the challenges facing evidence law, we can improve it. Behavioural science research into human irrationality, biases, other-race effects and decision-making can inform how juries are chosen, trained and instructed, so as to minimise human error. Forensic science research can inform best practice guidelines for what types of forensic evidence police collect and what kinds of expert witnesses are called in trials. The legal principles of evidence move slowly, but the content of the evidence itself changes quickly. With appropriate direction, funding, and professional training, the quality of evidence and legal outcomes in Australia can continue to improve.
Much like Brave New World the novel, this conference was a fascinating insight into some of the darker, more complicated aspects of human irrationality existing in a rapidly developing, and increasingly rational, technological and scientific world. But much like the novel, one of the conclusions that can be drawn is one of hope and potential. The research methods and technologies we have created can assist us in understanding ourselves, judges, juries and defendants. Whilst it is true that the relationship between science and law challenges us, our assumptions, and existing ways of reasoning, that relationship also offers us new understandings of evidence and juries, new forensic abilities to identify and convict criminals, and the potential for a more just world. Behavioural science, forensice science and evidence law all have contributions to make to each other and to society.
Marcus is a 4th year BSc/LLB(Hons) student, and is an ANUSA Science Representative.
Photo credit: Brave New Worlds Conference Advertising