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

Abstract

Purpose. Previous research on the reliability of eyewitnesses' facial composites suggests that some scepticism is warranted when evaluating their accuracy. The current research examines the degree to which mock jurors evaluate facial composite images as a source of incriminating or exonerating evidence against a defendant, particularly when they are inconsistent with other evidence presented. Method. Mock jurors read a fictitious criminal trial transcript of a person charged with armed robbery. Experiment 1 manipulated the facial composite evidence such that participants viewed a facial composite which was either a good or a poor match to the defendant. Experiment 2 also manipulated the quality of the facial composite evidence, as well as the other case evidence against the defendant. After reading the transcript, participants made several testimony‐relevant judgments about the case. Results. Mock jurors reacted more favourably towards the defendant when the facial composite resembled him than when it did not, but reacted similarly when the composite did not resemble the defendant vs. no composite presented. In addition, assessments of the strength of the composite evidence varied depending on the other case evidence presented. Conclusion. Mock jurors selectively incorporate evidence into their judgments about the credibility of the eyewitness and the culpability of the defendant. They responded to strong vs. weak facial composite evidence as one would expect: A good match composite was viewed as more favourable to the prosecution than a poor match composite. Weak facial composite evidence was largely ignored, however, participants' assessment of the strength of this evidence was adjusted to be consistent with the other evidence presented.

Evaluating the probative value of facial composites by laypeople and prosecutor apprentices

“…An important issue that needs to be addressed is the difference in results between present study and the results obtained by McQuiston-Surrett et al (2008), where the mock-jurors (laypeople) who viewed a good match facial composite responded favorably towards the eyewitness and punitively towards the defendant in comparison with the control group with no facial composite presented. The poor match composite however did not exculpate the defendant.…”

“…McAllister & Bregman, 1986;Kassin & Neumann, 1997). Therefore, the presence of identification evidence in the above-mentioned experiment by McQuiston-Surrett et al (2008) might have influenced their results instead of the intended manipulation of facial composite evidence. Therefore, in the experiment conducted for the purpose of this paper one has deliberately resigned from including identification evidence in case materials.…”

“…However, a facial composite may also serve as a source of incriminating or exonerating evidence against a defendant in court. This aspectthe diagnostic (or probative) value of facial composites, has been largely overlooked by researchers (with the exception of Charman, Gregory &Carlucci, 2009 andMcQuiston-Surrett, Bradfield Douglass &Burkhardt, 2008). However, residual laboratory data and case-law, suggest that facial composites may serve as evidence diagnostic of the guilt or innocence of a defendant.…”

“…At the same time a defendant may be convicted even in the absence of identification evidenceif other evidence prove beyond doubt that he or she is the culprit. Moreover, the experiment by McQuiston-Surrett et al (2008) that inspired the present research was conducted in a mock-juror paradigmi.e. involved laypeople in the field of law as subjects whose task was to simulate the decisions made by actual jurors.…”

“…Research on jury decision-making has expanded significantly over the years, developing around a number of psychologically and legally oriented topics (for a review see: Devine, Clayton, Dunford, Seying & Pryce, 2001). The choice of a mock-juror paradigm as a research method in the experiment by McQuiston-Surrett et al (2008) is justifiable in the US and other common law countries, in which the jury decides whether a defendant is guilty 1 . In countries with civil legal systems (including Poland) such decisions are made by judgestrained and experienced A c c e p t e d M a n u s c r i p t 5 lawyers.…”