The presentation of the case is undeniably more effective when traditional evidence is illustrated by demonstrative evidence. Demonstrative evidence adds variety to a trial and is often a refreshing break
for jurors from run-of-the-mill testimony. It also allows jurors to process evidence visually, in addition to auditorally. Used effectively, demonstrative evidence can add drama to the presentation of evidence and capture and hold the jury’s attention. In short, “[d]emonstrative evidence permits the trier of fact to itself observe a matter that is at issue rather than simply hear it described by the testimony of witnesses.” Daniel J. McAuliffe and Shirley J. Wahl, Arizona Practice, Civil Trial Practice, Vol. 2A § 21.19 at 70¬ 71 (2d ed. 2001).
Real or Illustrative Evidence
Demonstrative evidence can be either “real” (e.g., an actual accident scene, product or object or “illustrative” (i.e., evidence used to illustrate the testimony of witnesses)). Demonstrative evidence can take many forms. Photographs or video footage of a scene or object can be used to illustrate testimony and demonstrate physical characteristics of the scene or object. Witnesses can prepare sketches, diagrams or utilize other visual aids to illustrate and expand their testimony. Three-dimensional scale models of scenes can be effective not only to illustrate how an event occurred, but
also to visually demonstrate the location of witnesses and other salient information. Computer simulations and animations may also be used as demonstrative evidence provided required foundation for their admissibility is established. In appropriate cases, jurors may also be brought to a remote location to view a scene, building or large object that cannot easily be brought into the courtroom.
People can also be effectively used as “demonstrative evidence.” A plaintiff can demonstrate scarring, limitations in range of motion or physical characteristics that are at issue. Other witnesses (including
experts) and even attorneys may be utilized to make demonstrations for the jury.