Reading the Judicial Mind: Predicting the Courts' Reaction to the Use of Neuroscientific Evidence for Lie Detection

Abstract

How will the courts react to the emerging technology of detecting deception using neuroscientific methods such as neuro-imaging? The sociological theory of the autonomy of technology suggests that if neuroscientific techniques come to be seen as reliable for this purpose, other objections will soon be abandoned. The history of the judicial reaction to DNA evidence illustrates this pattern. As DNA evidence came to be seen as highly reliable, the courts rapidly abandoned their concerns that juries would be overwhelmed by the “mystique of science” and that the justice system would be “dehumanized.” The legal justifications for rejecting polygraph evidence are explored in order to illustrate that the judicial resistance to lie detection technologies, including neuro-imaging, can be expected to follow a similar pattern. The key determinant of whether courts are likely to accept neuroscientific evidence for the purpose of lie detection is the degree to which this evidence is considered to be reliable. Competing concerns about the “dehumanization” of the justice system, or the customary judicial attachment to protecting credibility determination as a purely human function, are unlikely to be able to overcome the pressure to adopt reliable neuroscientific technologies for lie detection should such technologies develop. This is because technologies that are widely accepted as reliable cannot be permitted to remain outside the justice system to deliver their own verdicts incompatible with those of the courts. The continued legitimacy of the justice system cannot tolerate this. The rules of evidence and, in particular, the constitutional right to make full answer and defense are the legal mechanisms by which this accommodation would take place.