Judging Post-Controversy Expertise: Judicial Discretion and Scientific Marginalisation in the Courtroom

The sexual assault trial of R v Hartman included evidence from a sleep expert who found himself increasingly marginalised within the scientific community. Marginalisation takes place following a scientific controversy, when those considered to be on the losing side find it increasingly difficult to be heard by the community, and in particular, their ideas are removed from core texts in the field. Given a marginalised expert's ambiguous status, and a scientific knowledge deficit on the part of legal actors, on what grounds does a judge base their decision around the evidential value of their testimony? An analysis of the judge's decision in the trial indicates that she evaluated the expert's evidence by employing a version of a socio-technical review that included expectations of scientific rigour based on mechanical objectivity and procedural correctness. Drawing upon these processes and expectations of sound science, the judge had little difficulty evaluating the expert's evidence and finding it unsafe. In particular, she drew attention to the expert's mobilisation of a conspiratorial discursive style, a product of his marginalisation. This supports certain STS claims that legal actors already have tools for evaluating appropriate expertise, and these continue to be the cornerstone of judicial decision-making around expert testimony, even in highly ambiguous situations like post-controversy science.