A Warning About Judicial Directions and Warnings

This article questions our criminal justice system’s heavy reliance on judicial directions and warnings. Reviewing a recent case and the directions provided by the trial judge — in a trial where a police officer purported to identify defendants on the basis of listening to intercepted telephone calls — this article explains why orthodox judicial instructions were incapable of assisting the jury with their assessment of the evidence. The analysis in this article explains why judicial directions do not necessarily mediate and therefore justify the admission of opinion evidence. In some cases, judicial directions are incapable of placing decision-makers in a position to rationally evaluate evidence. These conclusions draw on scientific research on voice identification and cognitive bias to illustrate how some judicial directions are not only displaced from scientific knowledge, but sometimes encourage (or expect) jurors to perform impossible feats of cognition.