Studies show that when people merely hear information, they recall only about 10 percent of what they heard. Approximately two-thirds of the population are visual learners. Jurors, like the rest of us, receive communication through an unprecedented amount of high-tech visual imagery. The brain processes visual evidence 60,000 times faster than text.
It is a basic tenet of effective trial advocacy that jurors must first understand something before they can be persuaded. At trial, two-thirds of the jury will be more receptive to evidence presented in a visual format rather than evidence presented verbally. When preparing any case for trial, using demonstrative evidence to tell a story often makes the difference between success and failure.
It is important to understand the distinction between "real evidence" which is usually defined as the actual thing involved in the case, such as the defective brake lining or the actual pathology taken from the plaintiff, and "demonstrative evidence" which is evidence not involved in the case and has no independent probative value in and of itself. Demonstrative evidence illustrates or represents real evidence or the testimony of a witness. Demonstrative evidence refers to anything you can see, hear, or touch, created for purposes of litigation. It serves as a visual aid to the witness as he explains his testimony, and to the jury in comprehending the verbal testimony of a witness, or other evidence. In other words, demonstrative evidence illustrates and clarifies.
- Properly authenticated financial records are evidence; a power point presentation depicting in graph format the company's finances is demonstrative evidence.
- The actual saw the plaintiff claims was defective is evidence; a model or a computer image of the saw, including a cutaway with color-coded parts, is a demonstrative tool.
- The significant historical events involved in the case are evidence; the timeline graphically depicting those events, in chronological order, is demonstrative evidence.
- Live testimony from a witness is evidence; if during examination a large note pad is created illustrating bullet points from that testimony, that item is a demonstrative aid.
In the above examples, the demonstrative aids are used to assist witnesses in explaining their testimony. Such exhibits, in and of themselves, are not relevant to the case; their relevance flows from the fact that by assisting a witness in testifying, they enhance the probative value of the testimony.
The trial judge has substantial discretion concerning the admissibility of demonstrative evidence. Exclusion will result if the prejudicial impact of the demonstrative aid outweighs its probative value. Also, in order to be used at trial, demonstrative evidence must be relevant - the item must be sufficiently explanatory or illustrative of relevant testimony in the case to be of potential help to the jury. To be relevant, i.e., to promote understanding, the item must also fairly and accurately portray what it purports to depict and, if relevancy so requires, to do so at the period of time relevant in the litigation. Mathematical accuracy is not generally required; however, if the demonstrative evidence does not aid in understanding because of inaccuracies, the exhibit may likely be excluded. Generally, the more accurate the exhibit, the more likely it is to be admitted into evidence. Essential matters depicted in the exhibit must be supported by a proper foundation.
The use of demonstrative evidence is one of the most effective tools for organizing information and educating a jury and the successful use of such evidence is limited only by counsel's creativity.