Esther Lim
INTRODUCTION
SCIENTIFIC VALIDITY
In 2008, an Indian lady, Aditi Sharma, was convicted of the murder of her former fiancé, making India the first country in the world to convict a criminal defendant of murder based on a brain scan which indicated “experiential knowledge” of the murder. The brain scan managed to convince the court that Aditi had a specific knowledge of murdering her fiancé, as opposed to merely having heard the details of his murder. The use of neuroscientific evidence, especially in a murder trial, was hotly debated, and sparked off huge debate throughout scientific and legal communities.
At present, there is no general consensus on the reliability of brain scans in detecting lies. As a commercialised technique, it has received much support from the private sector, with companies marketing the technique claiming that it is at least “90% accurate”.5 Yet, amongst researchers, the use of such technology in India was met with widespread skepticism, being called “shaky at best”6 and criticised due to lack of peer-review and independent replications.
Unsurprisingly, this debate has arrived in Singapore. In the Bioethics Advisory Committee’s 2013 public consultation paper on Neuroethics,1 the first of the six identified areas of concern was neuroimaging. While the applications of neuroimages, be it in research, medicine or courtrooms, are wide-ranging, the consultation paper drew attention specifically to the possibility of using brain scans as lie detectors in courts. It is thus worthwhile contemplating the possible implications of the use of neuroimages in criminal trials. There are two main methods of measuring brain activity which have been used to detect untruthfulness.2 The first, Functional Magnetic Resonance Imaging (fMRI), measures brain activity by creating magnetic images of blood oxygen in the brain. Active areas of the brain use more blood and consequently, show up brighter when imaged.3 Computer software creates a colour-coded three dimensional map of brain activity. The location of brain activity thus allows a researcher to infer how familiar a stimulus is to a subject by associating it with specific cognitive functions. The second method measures the brain’s electrical activity using electronencephalographic (EEG) sensors placed on the head.4 Researchers compare brain activity for stimuli, which are familiar or unfamiliar to the subject, to calibrate baselines which new stimuli are then compared to. The new stimuli can then be categorised as either familiar or unfamiliar. With both these methods, brain activity can either be measured when the subject is asked to actively respond to a series of questions, or when his or her passive perception to images or statements is processed. The goal is ultimately to demonstrate the accused has experiential knowledge that only the perpetrator of the crime would have. This paper deals with three main concerns with the use of neuroimages in lie-detection: first, the scientific validity of such evidence and, consequently, their admissibility in court, second, the implication of such techniques on the right against self-incrimination, and third, the effect on the right to privacy.
1 Bioethics Advisory Committee, Singapore, Ethical, Social and Legal Issues in Neuroscience Rearch: A Consultation Paper. 2 Brian Farrell, “Can’t Get You Out Of My Head: The Human Rights Implications of Using Brain scans as Criminal Evidence” [2009] 4 Interdisciplinary Journal of Human Rights Law 89. 3 Matthew Holloway, “One Imagine, One Thousand Incriminating Words: Images of Brain Activity and the Privilege against Self-Incrimination”, [2008] 27 Temp. J. Sci. Tech. & Envtl L. 141. 4 Mark Pettit, Jr., “FMRI and BF meet FRE: Brain Imaging and the Federal Rules of Evidence,” [2007] 33 Am. J. L. & Med. 319.
Singapore’s Evidence Act 1997 provides the framework of rules for the types of evidence that can be admitted during court proceedings. Section 47 of the Act concerns the expert opinions of third persons “upon a point of scientific, technical or specialised knowledge.” However, s.47 does not stipulate a test for whether a field of expertise, neuroimaging lie detectors in this case, is one worthy of recognition by the law of evidence. Authoritative interpretations in Singapore on how scientific evidence is evaluated in courts are relatively rare. However, the Report of the Law Reform Committee on Opinion Evidence7 has taken two cases as instructive in this matter. Firstly, in the case of Nadasan Chandra Secharan v Public Prosecutor,8 involving the DNA analysis of a tooth fragment, Yong Pung How CJ said, “We do not doubt the immense value of DNA evidence and its use in criminal trials. However, every failure of the procedure stated in the validation paper would, in our view, affect the weight to be attributed to the expert evidence unless there were other independent sources to verify and confirm that such departures did not affect the reliability of the findings.” In PP v Tay Wee Guan,9 Rajendran J said, “DNA evidence is indeed a very useful tool in the prosecution’s armory. It is, however, a relatively new and esoteric science and every effort should be taken to have a clear understanding of its implications and limitations before reliance is placed on it.” The Law Reform Committee has interpreted these two cases to indicate that Singapore’s approach to evidence from novel fields of science would be similar to the stance adopted in English courts, as established by Kennedy LJ in R v Dallagher,10 where there is a low barrier of admissibility for such evidence, but the court evaluates the weight attached to evidence arising from “novel science.” This is unlike the case in the United States and New Zealand, where the Daubert and Calder rules (elaborated on below) respectively set a high barrier to admissibility of evidence. Rather, it is likely that either the Daubert or Calder rules will be used when deciding how much weight to attach to the evidence. The Daubert rules come from the United States, where discourse on which emerging fields of knowledge can be applied in courts is most extensive. The test was developed in Daubert v Merrell Dow Pharmaceuticals, Inc11 and requires that the evidence be grounded in the scientific method and relevant to the inquiry before the courts. The courts, while not wishing to “set out a definitive checklist or test”, also suggested further criteria, such 5 See http://www.noliemri.com/products/overview.htm. 6 Giridharadas, Anand. “India’s Novel Use of Brain Scans in Courts is Debated,” New York Times 14 Sept 2008. 7 Vinodh Coomaraswamy, S.C., Report of the Law Reform Committee On Opinion Evidence, Singapore Academy of Law, October 2011. 8 [1997] 1 SLR 723. 9 [1997] SGHC 133. 10 [2002] EWCA 1903. 11 Daubert v Merrell Dow Pharmaceuticals, Inc., 509 U.S. 579 (1993).
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