Visual evidence.

Visual and other demonstrative evidence has become increasingly prevalent in American and other courtrooms in recent years. However, there have been relatively few experimental studies of the effects of this kind of evidence in legal settings. As a consequence, little is known about when and how it affects legal decision making. In this article, I survey the extant research, including studies of photographs, videos, computer animations, and PowerPoint displays. The research shows that visual evidence affects legal decisions in some circumstances but not in others. It also indicates that visual evidence sometimes enhances legal judgment by improving recall and understanding but sometimes impairs judgment by prompting undue emotional responses, cognitive and perceptual biases, and/or peripheral processing. The limitations of the research are discussed, and directions for future research are suggested.