- Relevance. The evidence must have a connection with a material fact that is at issue in the case.
- Identification and authentication. The sources of facts included in the evidence must be identified and authenticated. In other words, the demonstrative item must not include information that is not otherwise already established in the case. If the evidence presents information that is based on expert analysis or testimony, a qualified witness may need to confirm its accuracy.
- Usefulness. Evidence needs to be useful to the fact finder (the judge or the jury) to be admitted. “Useful” means, among other things, that the information is presented in a clear and accurate way. By definition, the evidence can’t be deceptive, misleading, or confusing. A chart that distorts a critical piece of information, for example by displaying it in particularly large text compared to the rest of the chart, might be deemed misleading.
Demonstrative evidence can be a powerful tool for establishing a legal case. In broad terms, demonstrative evidence refers to materials prepared by a legal team to summarize or illustrate other forms of evidence—raw data, witness testimony, collections of photographs, and so on—in a way that will help a judge or jury interpret and understand it. Demonstrative evidence might come in the form of chart, a table, or a map. Critically, demonstrative evidence has been prepared specifically for trial in reliance upon an underlying set of information. Because demonstrative evidence is created by a party in the litigation it must meet strict standards to be admitted in court, as determined by Nevada’s evidence law. In simplified terms the evidence needs to have the following characteristics: