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The Use of Demonstratives in Patent Litigation

By Paul A. Ragusa and Peter J. Shen, Ph.D.
December 02, 2004

A picture is worth a thousand words ' or perhaps more ' when the concept being described is complicated, abstract or unfamiliar. By its very nature, the technology associated with a patent demands the use of visual and other aids in order to be understandable by a juror, judge, or other trier of fact. Not surprisingly then, demonstratives are essential tools in patent litigation to illustrate or contradict fact and expert witness testimony, as teaching aids in Markman hearings, and in opening and closing arguments. A number of legal and practical considerations should be kept in mind when preparing and using demonstrative aids.

Legal Requirements

A patent litigator must be prepared to defend the use of any particular demonstratives because, absent stipulation, opposing counsel may always seek to preclude the use of the material in court. They are subject to the credibility of the underlying evidence, such as witness testimony. For example, opposing counsel can cross-examine as to the fairness and accuracy of demonstratives used by the witness. The courts are split as to whether demonstrative exhibits should be considered substantive evidence, and thus admissible in evidence. Compare United States v. Janatti, 374 F.3d 263, 273 (4th Cir. 2004) (“These 'pedagogical' devices are not evidence themselves, but are used merely to aid the jury in its understanding of the evidence that has already been admitted.”); with Verizon Directories Corp. v. Yellow Book USA, Inc., 331 F. Supp. 2d 136, 142 (E.D.N.Y. 2004) (“Subject to Rule 403, with somewhat more stringent control in jury trials, pedagogical aids should generally be admitted as evidence.”). Their introduction or admissibility in court is, pursuant to Fed. R. Evid. 611(a), at the sole discretion of the trial judge whose decision on such matters, reviewed for abuse of discretion, is only disturbed in exceptional circumstances. See, e.g., United States v. Crockett, 49 F.3d 1357, 1362 (8th Cir. 1995) (“We emphasize that the district courts have virtually unfettered discretion to regulate the use of such non-evidentiary devices.”). With this in mind, the litigator must take care in preparing demonstratives to maximize the odds that the fact-finder will consider them.

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