Can Defense Attorneys Detect Forensic Confirmation Bias?

Abstract

Abstract. Knowledge of task-irrelevant information undermines the probative value of forensic evidence (i.e., forensic confirmation bias). Cross-examination may sensitize jurors to bias – but do attorneys recognize when bias has tainted evidence against their client and adjust their cross-examination strategy accordingly? To address this question, 130 defense attorneys imagined representing a man charged with manslaughter and reviewed a case file that included, among other things, an autopsy report from a medical examiner who was either aware or unaware of their client’s recanted confession before ruling the death a homicide. When the examiner knew of the confession, attorneys rated the autopsy as no less probative or reliable, they were no less confident in their client’s guilt, and only 46% raised the possibility of confirmation bias on cross-examination. Our findings suggest that defense attorneys underappreciate the impact of forensic confirmation bias, such that biased forensic testimony would be better avoided via procedural reform.