Effects of false-evidence ploys and expert testimony on jurors, juries, and judges

Triers of fact evaluated trial materials involving disputed confessions, false-evidence ploys (FEPs) during interrogation, and expert testimony. In two experiments, we assessed pre-deliberation and post-deliberation trial decisions as well as individual jurors’ perceptions, deliberating juries’ verdicts, and sitting judges’ perceptions and trial decisions. Judges convicted more often than did juries. Although triers of fact recognized the deception inherent in FEPs, the use of FEPs in police interrogations did not affect these decision-makers’ trial outcomes. Expert testimony, however, affected perceptions and reduced jurors’, deliberating juries’, and sitting judges’ likelihood of conviction. We provide recommendations for courts, scholars, and police interrogators