The Legal and Scientific Challenge of Black Box Expertise

Abstract

Legal commentators widely agree that forensic examiners should articulate the reasons for their opinions. However, findings from cognitive science strongly suggest that people have little insight into the information they rely on to make decisions. And as individuals gain expertise, they rely more on cognitive shortcuts that are not directly accessible through introspection. That is to say, the expert’s mind is a black box – both to the expert and to the trier of fact. This article focuses on black box expertise in the context of forensic examiners who interpret visual pattern evidence (e.g., fingerprints). The authors review black box expertise through the lens of cognitive scientific research. They then suggest the black box nature of this expertise strains common law admissibility rules and trial safeguards.

Keywords: evidence law, psychology, cognitive psychology, experts, expert witnesses, expert evidence law, scientific evidence, forensic science, fingerprint analysis

JEL Classification: K10, K14, K30, K42