Educating Jurors about Forensic Evidence: Using an Expert Witness and Judicial Instructions to Mitigate the Impact of Invalid Forensic Science Testimony.

Abstract

Invalid expert witness testimony that overstated the precision and accuracy of forensic science procedures has been highlighted as a common factor in many wrongful conviction cases. This study assessed the ability of an opposing expert witness and judicial instructions to mitigate the impact of invalid forensic science testimony. Participants (N = 155) acted as mock jurors in a sexual assault trial that contained both invalid forensic testimony regarding hair comparison evidence, and countering testimony from either a defense expert witness or judicial instructions. Results showed that the defense expert witness was successful in educating jurors regarding limitations in the initial expert's conclusions, leading to a greater number of not-guilty verdicts. The judicial instructions were shown to have no impact on verdict decisions. These findings suggest that providing opposing expert witnesses may be an effective safeguard against invalid forensic testimony in criminal trials.

Journal

Journal ID (iso-abbrev): J. Forensic Sci.

Title: Journal of forensic sciences

Publisher: Wiley

ISSN (Electronic): 1556-4029

ISSN (Print): 0022-1198

Publication date (Electronic): November 2015

Volume: 60

Issue: 6

Affiliations

[1 ] Faculty of Social Science and Humanities, University of Ontario Institute of Technology, Oshawa, ON, Canada.

[2 ] Faculty of Science, University of Ontario Institute of Technology, Oshawa, ON, Canada.

Article

DOI: 10.1111/1556-4029.12832

PubMed ID: 26234166