Factors Which Influence Jurors’ Interpretation of the Value of Forensic Science Testimony

1. Factors Which Influence Jurors’ Interpretation of the Value of Forensic Science Testimony National Institute of Justice & RTI Center for Forensic Science Impression, Pattern and Trace Evidence Symposium January 24, 2018 Alicia B. Wilcox, PhD CLPE, CSCSA, CFPH, CFWE Assistant Professor, Husson University Factors Which influence Jurors’ Interpretation of the Value of Forensic Science Testimony Alicia B. Wilcox, Assistant Professor, Husson University

2. Reason for the Research “Jurors’ use and comprehension of forensic evidence is not well studied. Better understanding is needed in this area, and recommendations are need for … methods that will better prepare juries… for trials in which scientific testimony is expected to play a large or pivotal role” (National Research Council, 2009)”. Factors Which influence Jurors’ Interpretation of the Value of Forensic Science Testimony Alicia B. Wilcox, Assistant Professor, Husson University

3. Research Process Factors Which influence Jurors’ Interpretation of the Value of Forensic Science Testimony Alicia B. Wilcox, Assistant Professor, Husson University

4. Findings • Jurors rated years of experience and education as the most important qualifications in an expert witness • Credibility of the expert witness correlated with how reliable the jurors thought the forensic evidence • How the expert testified influenced how reliable the evidence was perceived by the jurors Factors Which influence Jurors’ Interpretation of the Value of Forensic Science Testimony Alicia B. Wilcox, Assistant Professor, Husson University

5. Qualifications of Expert witnesses • Statistically significant inverse correlation between University education and Years of Experience • Statistically significant inverse correlation between certifications and on the job training • Jurors tended to put weight on formal education or skills learn on the job Factors Which influence Jurors’ Interpretation of the Value of Forensic Science Testimony Alicia B. Wilcox, Assistant Professor, Husson University

6. Expert Witness Credibility • The jurors based the credibility of the expert witnesses on the following criteria: • How they described their qualifications and experience as related to forensic science • Their confidence and demeanor • How the expert explained the scientific evidence • Being called by the government/ state as an expert Factors Which influence Jurors’ Interpretation of the Value of Forensic Science Testimony Alicia B. Wilcox, Assistant Professor, Husson University

7. Expert Witness Credibility Factors Which influence Jurors’ Interpretation of the Value of Forensic Science Testimony Alicia B. Wilcox, Assistant Professor, Husson University

8. Factors Which influence Jurors’ Interpretation of the Value of Forensic Science Testimony Alicia B. Wilcox, Assistant Professor, Husson University

9. Evidence Reliability • The jurors based the reliability of the forensic science evidence on the following criteria: • Chain of custody • Corroborated evidence • Significance to the case • Their knowledge about the evidence • The science behind the evidence Factors Which influence Jurors’ Interpretation of the Value of Forensic Science Testimony Alicia B. Wilcox, Assistant Professor, Husson University

10. Evidence Reliability Factors Which influence Jurors’ Interpretation of the Value of Forensic Science Testimony Alicia B. Wilcox, Assistant Professor, Husson University

11. Factors Which influence Jurors’ Interpretation of the Value of Forensic Science Testimony Alicia B. Wilcox, Assistant Professor, Husson University

12. The Forensic Scientist Represents the Evidence • 68% of the jurors rated the forensic science evidence more important in their decision making than the police evidence or lay witnesses • It was observed that jurors appear to base the reliability of the forensic evidence on their perception of the expert witness’s credibility with a moderate positive correlation* between jurors’ perceptions of the reliability of evidence and the credibility of the witness. *(Pearson’s correlation coefficient of +0.44, N=29, P= .01) Factors Which influence Jurors’ Interpretation of the Value of Forensic Science Testimony Alicia B. Wilcox, Assistant Professor, Husson University

13. How Jurors process trial information • Central and Peripheral processing • Story Model • Strength of the Evidence Factors Which influence Jurors’ Interpretation of the Value of Forensic Science Testimony Alicia B. Wilcox, Assistant Professor, Husson University

14. Testimony Style and the Strength of the Evidence (SOE) • Verdicts are driven by the Strength of the Evidence (SOE) • Testimony • Probabilistic weight • Narrative Language • Demonstrative aids- charts, PowerPoint slides, diagrams • Jurors in the study explained that it was important to them to be able to understand the strength of the evidence themselves rather than just trusting the expert witness. • Jurors placed more weight in their decision making on forensic science testimony where the forensic science expert spent time teaching the jury about the steps they went through to come to their conclusion. Factors Which influence Jurors’ Interpretation of the Value of Forensic Science Testimony Alicia B. Wilcox, Assistant Professor, Husson University

15. In Summary • Jurors rated years of experience and education as the most important qualifications in an expert witness • Credibility of the expert witness correlated with the interpretation of the reliability of the evidence • How the expert testified influenced how reliable the evidence was perceived by the jurors Factors Which influence Jurors’ Interpretation of the Value of Forensic Science Testimony Alicia B. Wilcox, Assistant Professor, Husson University

16. Acknowledgements • The jurors who voluntarily participated in this study • Chief Justice Cole and former Chief Justice Humphrey • Heidi Carpenter, Judicial Assistant, Cumberland Superior court • Attorneys General Lisa Marchase, Deborah Cashman and Leanne Zainea • Victim-witness advocates Michelle Cram and Laura Mintzer • Management and the scientific staff at the Maine State Police Crime Laboratory • Professor Niamh Nic Daeid -Dundee University, Scotland • Dean Marie Hansen- Husson University Factors Which influence Jurors’ Interpretation of the Value of Forensic Science Testimony Alicia B. Wilcox, Assistant Professor, Husson University

17. Questions? Factors Which influence Jurors’ Interpretation of the Value of Forensic Science Testimony Alicia B. Wilcox, Assistant Professor, Husson University