A study of the persuasiveness of animation when used as forensic demonstrative evidence

Abstract

Previous studies have determined that computer-animated displays have a persuasive impact on jury members. This study assessed the hypothesis that motion was the key design variable which makes forensic animation persuasive. Participants read a trial transcript involving a dispute over whether a woman intentionally shot and killed her husband or accidentally killed him while wrestling over a gun. Participants were then divided into three groups. The first group watched either a proprosecution animation in which the woman intentionally pointed the gun and shot her husband or a prodefense animation in which she accidentally shot him while they were wrestling. The second group saw either proprosecution or prodefense images taken from the animations. The third group did not see any visual imagery. The proprosecution imagery coincided with the physical evidence regarding the path the bullet traveled though the man's body. The prodefense imagery contradicted the physical evidence. In the proprosecution cells, only the animation group produced a significant increase in confidence that the woman intentionally murdered her husband. In the prodefense cells, there was no significant change between the animation group, the video stills group, or the control group. Results suggest that when computer-animated displays support the physical evidence, it is the dynamic nature of the animation which makes it persuasive to jury members.