In recent years, the use of visual evidence and arguments in courtrooms has exploded, but empirical research on the effects of these tools on legal decision-making has just begun. Lawyers, judges, and juries are faced with a barrage of evidence and argument displayed in visual form?often gruesome in nature. Judges routinely permit graphic photographs into evidence in criminal (body of a murder victim) and civil (depiction of a gangrenous extremity) cases because they believe their probative value outweighs their prejudicial effect. How do emotionally evocative images affect the psychology of jurors? decision making? Do gruesome photographs pose a danger of unfair prejudice by making jurors more conviction-prone? This project was designed to conduct a theoretically driven investigation of how and why gruesome photographs increase guilt and punishment judgments?and to test potential interventions that might diminish the prejudicial effects of seeing gruesome images. Finally, we extended this line of research to emotion measures that do not rely on subjective self-report (physiological monitoring, pupil dilation).

Across our experiments, we have discovered that gruesome photographs make mock jurors more conviction prone before they deliberate together?an effect we replicated in the majority of our studies.

We also identified several psychological explanations for the impact of gruesome photographs on convictions. First, viewing gruesome photographs increases mock jurors' disgust response, which in turn is related to increased convictions. Second, viewing gruesome photographs (compared to hearing details of the injury verbally from a pathologist) also instigates a biased or "directed" processing of evidence unrelated to the photographs or victims' injuries to support a conviction. This suggests that emotional reactions to gruesome images might start a biased processing of other evidence to confirm a conviction.

We also replicated the gruesome-photo effect in a civil case.

Across several experiments, we found mixed results regarding potential interventions designed to mitigate the prejudicial impact of gruesome photographs. We found that judicial instructions designed to draw jurors' awareness to the potentially biasing impact of their emotional responses to gruesome photographs eliminated the effect of gruesome photographs on convictions. However, in a follow-up study that recruited in-person participants and included deliberation the jury instructions did not reduce the impact of gruesome photographs. Presenting the gruesome photographs in B&W did not mitigate the impact of gruesome photographs. Regarding deliberation, we have preliminary results showing that gruesome photographs significantly increased convictions before deliberation, but that in-person deliberation potentially eliminates that gruesome photograph effect after deliberation.

In addition, we investigated whether the impact of gruesome photographs on jurors? emotions and case judgments depends on the victim's race. We found evidence that gruesome photographs rouse moral emotions in jurors and, in turn, greater convictions?but only when the victim is a White woman; White mock jurors do not have the same emotional reactions and increased conviction-proneness with they see gruesome photographs of Latina or Black women. We also found that presenting the combination of a murder victim before she did alongside gruesome postmortem photographs is particularly impactful. Thus, presenting victim photographs might exacerbate racial bias in emotional responses to victim and verdicts.

We have published 3 articles and 2 chapters, and have several manuscripts in progress. We have presented the research at 15+ academic conferences and 14+ other presentations to legal audiences. The PI has also testified in several cases about the impact of emotionally disturbing evidence on jurors' judgments.

Intellectual Merit

This project identified ways that gruesome photos might introduce unfair prejudice, and will be the first to test how viewing gruesome photographs affect psychological responses, attention to other evidence, and in turn, legal judgments. It is the first to test the effects of gruesome photographs on jury-level outcomes, and how riling emotions via gruesome photographs might change the quality of the group deliberation process. It provided insight into the effectiveness of practical legal safeguards that might reduce the prejudicial effects of these photographs, while maintaining the probative information (B&W vs. color photographs, jury instructions, group deliberation). Identifying psychological mechanisms by which photographs influence judgments (emotional responses, attention to other evidence, deliberation processes) informs legal doctrine by clarifying the circumstances under which these photographs are likely to result in unfair prejudice.

Broader Impacts

The current project has important practical implications for judges who must make difficult determinations about whether the prejudicial effect of gruesome photographs outweigh their probative value. Judges are largely left to play armchair psychologist and rely on their assumptions about how these photographs affect the decision-making process. The research provides guidance to judges about the psychological impact of viewing disturbing, gruesome photographs on jurors, and how it could prejudice them towards a conviction. It also highlights how exposing jurors to these images can exacerbate racial bias toward Latina and Black victims because they selectively elicit moral emotional reactions inly when the victim is a White woman.

Last Modified: 10/18/2023
Modified by: Jessica Salerno