|Part of the common law series|
|Types of evidence|
|Hearsay and exceptions|
|Other common law areas|
Examples of demonstrative evidence include photos, x-rays, videotapes, movies, sound recordings, diagrams, forensic animation, maps, drawings, graphs, animation, simulations, and models. It is useful for assisting a finder of fact (fact-finder) in establishing context among the facts presented in a case. To be admissible, a demonstrative exhibit must “fairly and accurately” represent the real object at the relevant time. See Federal Rules of Evidence 901, 902, and 1001-1004 for an example from United States law.
Other examples of demonstrative evidence include case specific medical exhibits, colorized diagnostic films, general anatomy and surgery exhibits. These forms of demonstrative evidence are commonly used as a personal injury lawyer resource. Demonstrative evidence with dramatic impact can maximize the value of a case by effectively depicting catastrophic/traumatic injuries, complex surgical procedures, surgical mistakes or summarize injuries suffered by an individual. These examples of demonstrative evidence are used for settlement conferences, arbitration, mediation, medical expert depositions and trial presentations.
Before photographs and other demonstrative evidence, lawyers relied on purely testimonial or substantive evidence. Melvin Belli and Earl Rogers helped change that by introducing more demonstrative evidence. Scientific evidence emerged in the 1960s.
Mechanics of use
In American jurisprudence, demonstrative evidence, like any other kind of evidence must be relevant. At this point the proponent of the demonstrative evidence can either try to get the evidence admitted into the official record of the case or can choose to use the evidence as merely a prop. If the proponent of the evidence wants to have the evidence included in the official record of the case, the proponent will first ask for the evidence to be marked by the court for identification purposes. After the evidence is marked for identification, the proponent of the demonstrative evidence must lay a foundation. It is at this time that the relevancy of the demonstrative evidence is usually challenged. Laying of a foundation explains how the demonstrative evidence relates to the facts of the case and establishes the evidence's authenticity. Once the foundation is laid, the proponent may ask to officially move the piece of evidence into the record where it is marked as a full exhibit. If the evidence is marked as a full exhibit the jury may refer to the evidence during deliberations and in most jurisdictions the jury may examine the evidence during deliberations. If the evidence is not marked as a full exhibit, the jury cannot do these things. As a matter of courtesy, the proponent of the demonstrative evidence generally shows the piece of evidence to the opposing party before marking it for identification purposes. In criminal cases certain kinds of demonstrative evidence are subject to mandatory disclosure under the case law governing discovery. See Brady v. Maryland.
Examples of demonstrative evidence from popular culture include their use in these motion pictures:
- The Rainmaker - use of a plaque to show the number of claims filed and accepted
- Erin Brockovich - charts and files
- A Few Good Men - logs and photographs
- My Cousin Vinny - photographs, tape measure
Ronald J. Rychlak, Real and Demonstrative Evidence: Applications and Theory (Lexis-Nexis, 2nd ed. 2002)