Technology on trial: facilitative and prejudicial effects of computer-generated animations on jurors’ legal judgments

ABSTRACT

The current study explored how a computer-generated animation (CGA) illustrating a defendant’s version of events affected jurors’ judgments in a mock second-degree murder trial. We hypothesized that mock jurors who viewed a CGA illustrating the defendant’s testimony would be more likely to acquit compared to those who viewed static visual images or did not view a visual aid, and that this effect would occur regardless of whether the narrative depicted in the CGA was corroborated by pertinent testimonial evidence. In this 2 (testimony congruence: incongruent vs. congruent) x 3 (testimony modality: no-aid vs. static visual aid vs. computer-generated animation) between-subjects design, undergraduate students (N = 238) read a transcript from a fictitious trial and heard the defendant’s testimony in one of three modalities. Across congruence conditions, participants were significantly more likely to acquit the defendant when his testimony was accompanied by a CGA (OR = 5.08), compared to a static visual aid or with no-aid. Our results suggest that CGAs may have a disproportionate impact on jurors’ judgments compared to traditional forms of demonstrative evidence. Whether this impact is facilitative or prejudicial, however, depends on whether the content of the animation is congruent or incongruent with other case evidence.

KEYWORDS:

• computer-generated animations
• digital evidence
• legal decision-making
• cognitive processes

Data Availability statement

The data that support the findings of this study are available from the corresponding author [author initials], upon reasonable request.

Disclosure statement

No potential conflict of interest was reported by the author(s).

Notes

1 Operationally, support for the facilitation and prejudice hypotheses was predicated on three statistical predictions. First, we expected a significant main effect of modality, such that participants in the animation condition would be more likely than those in the static visuals or no-aid condition to render not-guilty verdicts. Second, we expected a significant main effect of congruence, such that participants in the congruent condition would be more likely to render not-guilty verdicts than those in the incongruent condition. Third, we expected a non-significant interaction between these variables. If these three conditions were met, with the computer-generated animation increasing the likelihood of participants' acquitting the defendant across congruence conditions (i.e. a non-significant interaction between modality and congruence), the study will have provided evidence that the animation facilitated participants' judgments in the congruent condition (wherein an acquittal is supported by other key case testimony) as well as prejudicing participants' decisions in the incongruent condition (wherein an acquittal is discrepant with other key case testimony).