Juror Underutilization of Eyewitness Nonidentifications: A Test of the Disconfirmed Expectancy Explanation¹

Abstract

The impact of two types of eyewitness testimony on mock jurors' judgments was explored. A crime eyewitness either testified that the defendant definitely was the robber (identification), definitely was not the robber (nonidentification), or that they weren't sure if he was or was not the robber (control). An alibi eyewitness testified that the defendant either definitely was at the alibi location (identification), definitely was not at the alibi location (nonidentification), or he wasn't sure if the defendant was or was not at the alibi location (control). Strength of case was also manipulated. Results show that crime eyewitness identifications and alibi eyewitness nonidentifications were underutilized. A crime eyewitness by alibi eyewitness interaction revealed that within the crime eyewitness identification condition alibi identification was underutilized whereas with the other two crime eyewitness conditions, alibi nonidentification information was underutilized. The results supported a disconfirmed expectancy explanation.

The Influence of Identification Decision and DNA Evidence on Juror Decision Making1

“…McAllister and Bregman (1989) suggested that non‐identifications should be perceived as equally diagnostic as positive identifications in which a witness identifies the suspect (also see Wells & Olson, 2003). The results of the current study suggest that jurors did not always perceive these types of identifications to be equal in diagnostic value.…”

Evaluation of facial composite evidence depends on the presence of other case factors

“…A handful of studies support this idea of a confirmatory bias in the consideration of evidence. For example, some research indicates that jurors underutilize eyewitness non‐identifications when this information disconfirms an earlier hypothesis about defendant culpability (Leippe, 1985; McAllister & Bregman, 1986, 1989; see also Wells & Lindsay, 1980) and others argue that jurors' consideration of corroborating vs. contradictory eyewitness testimony depends on whether the testimony confirms their beliefs about defendant guilt (Lindsay et al , 1986). Future research should continue to investigate jurors' selective consideration of evidence, particularly under more ecologically valid conditions.…”

“…Specifically, people's selective use of eyewitness information to support their conclusion about the evidence is suggested by a handful of studies (e.g. Leippe, 1985; McAllister & Bregman, 1986, 1989). An unexplored situation in which selective use of eyewitness evidence by jurors might occur is in the evaluation of a facial composite created by the eyewitness.…”

Where I was and how I will prove it

“…Most of the research conducted on alibis to date has addressed the evaluation of suspects' alibis. In such studies, undergraduate students are asked to take on the role of a juror and rate the guilt of a defendant who presented an alibi and potential supportive evidence for it Lindsay, Lim, & Marando, 1986;McAllister & Bregman, 1989;. The results of these studies are consistent with the taxonomy of , showing that the stronger the supportive evidence, the less guilty the participants rated the defendant.…”