Comparison of Eyewitness and Physical Evidence on Mock-Juror Decision Making

• NCJ Number: 191721
• Journal: Criminal Justice and Behavior Volume: 28 Issue: 5 Dated: October 2001 Pages: 614-630
• Author(s): Paul Skolnick; Jerry I. Shaw
• Date Published: October 2001
• Length: 17 pages
• Publication Format: Article
• Publication Type: Report (Study/Research)
• Language: English
• Country: United States of America

Annotation

This article presents research on the impact of eyewitness and physical evidence on mock-juror decision making.

Abstract

Two studies compared the impact of eyewitness testimony and physical evidence on mock-juror decision making. Ninety jury-eligible participants were randomly assigned to read one of eight versions of a hypothetical murder scenario and were each asked to render a verdict, to recommend a sentencing option, and to make other evaluative judgments of the defendant. In Study 1, either eyewitness testimony or physical evidence was presented. In Study 2, both types of evidence were presented together. The strength of evidence varied in both studies. Consistent with the hypothesis, the data in Study 1 show that both eyewitness and physical evidence are important factors in mock-jury decision making. The data indicate that mock jurors’ decisions are influenced more by physical evidence than by eyewitness testimony. This is in spite of the facts that eyewitness testimony is known to be highly influential in forming jurors’ opinions and jurors tend to underrate the importance of physical evidence. A direct comparison between the two types of evidence shows a significantly greater number of guilty verdicts were obtained with physical evidence than with eyewitness evidence. Study 2 supported this conclusion by finding more guilty verdicts when physical evidence was strong than when eyewitness evidence was strong. This effect was obtained even when the confound between strength of evidence and type of evidence that existed in Study 1 was eliminated. Consistent with the conclusion that physical evidence exerts more influence on mock-juror judgments than does eyewitness evidence, a stronger effect size was obtained for physical evidence than for eyewitness evidence on attribution of responsibility. Furthermore, personal evaluations of the defendant were dependent only on physical evidence, not on eyewitness testimony. 2 notes, 2 tables, 34 references