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

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.