DOI: 10.3886/icpsr36169.v1
title: Jurors' Judgments About Forensic Identification Evidence, Arizona, 2011-2014
title: Version 1

description: This data file describes three different experiments that were designed to examine how differences in the way forensic scientific evidence is communicated affects jurors. In each experiment, participants consisted of jury-eligible community members in Maricopa County, Arizona. Groups of participants attended a research session in which they were shown a 35-40-minute videotapes of one of two mock criminal trials (one, a rape case, centers around bitemark evidence, and the other, an attempted murder, centers around fingerprint evidence). Within each trial the content of a forensic scientist's testimony was manipulated. These manipulations involved: 1) whether the technique used by the forensic scientist was "high tech" or "low tech," 2) the amount of experience possessed by the forensic scientist, 3) whether the technique used by the forensic scientist had been scientifically validated, 4) whether the forensic scientist conceded that an error was possible, and 5) whether any exculpatory evidence was present at the crime scene. Immediately following the trial, each individual participants completed a questionnaire in which they gave their individual impressions of the strength of the case. Following that, the group of participant would deliberate and attempt to reach a unanimous verdict. Finally, each individual participant completed an additional questionnaire that again measured perceptions of the case along with individual difference measures and demographics.
description: The purpose of the study was to garner a better understanding of how jurors respond to forensic identification expert testimony presented at trial. Researchers pursued this goal by conducting a series of controlled studies involving jury simulations (experimental studies in which the researcher attempts to construct a setting that mirrors a jury decision-making environment) or mock trials. The first experiment examined how an expert's experience level, the "tech-factor" of the methods used (high-tech vs low-tech), and the extent to which the expert's methods have been scientifically validated combine to influence jurors' judgments about the forensic evidence. The second experiment examined the forensic expert's subjective level of certainty over his findings combined with the presence or absence of any exculpatory forensic evidence. The third experiment examined the scientific validity of a forensic technique combined with whether the forensic expert concedes that forensic identifications may be made in error.
description: Researchers used a "mock-trial paradigm" in which they created fictitious criminal trials and asked a sample of laypeople to serve as "jurors" in the cases. As a starting point, they created two completely different cases: one, a rape case, involved a defendant who allegedly bit the victim's shoulder, leaving a bitemark behind. The second case, an attempted murder, included fingerprints left behind on a mug that the suspect had touched during the crime. Both trials were strategically designed such that the strength of the forensic evidence - bitemark or fingerprint - would be the key piece of evidence that jurors would use to base their decisions.
description: Variables related to experiment 1 include variables on the level of technology in the presented evidence, the experience of the expert, and the scientific testing of technique. Variables related to experiment 2 include variables on the strength of exculpatory evidence, and the subjective certainty of the expert. Variables related to experiment 3 include variables on the scientific testing of the technique, and the concession that an error is possible.
description: Not applicable.
description: Response Rates: Not available.
description: There were two samples for this study: One of rejected jurors in Phoenix, AZ, and another of mock trial jurors recruited by a market research firm.
description: Datasets: DS1: Jurors' Judgments About Forensic Identification Evidence, Arizona, 2011-2014
description: Jury-eligible residents of Maricopa County, AZ. Smallest Geographic Unit: County
description: face-to-face interview; mixed mode