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Admissibility of Computer-Generated Animations

January 5, 2018 in  News

New York Law Journal 

This article revisits the issue of admissibility of computer-generated animations purporting to reconstruct a series of events or an accident. The discussion is stimulated, in part, by the speed with which a younger generation of trial lawyers is itching to use the latest technology in evidence presentation techniques and, thereby, effectively communicate with a new generation of jurors accustomed to the instantaneous delivery of information that resonates. Already, some courtrooms are being upgraded to handle multi-screen presentations. An article on “Technology in the Courtroom” by Kentucky trial lawyer Michael Patrick briefly summarizes some of the dynamics of change.

In 2004, U.S. Southern District of New York Judge Jack B. Weinstein issued his visionary opinion in Verizon Directories v. Yellow Book USA, 331 F. Supp. 2d 136 (E.D.N.Y. 2004), favoring admissibility of computer-generated demonstrative exhibits or techniques referred to as “pedagogical devices.” Judge Weinstein was confident that judges could control against abuses or inequities in resources and tailor proceedings so that such demonstrative materials would help jurors find the truth.

Judge Weinstein defined four categories of such demonstrative exhibits: (1) “static images” (common in courtrooms, such as tables, graphs, maps and diagrams); (2) “animations” (moving pictures in which static images are shown in rapid succession to create the illusion of motion); (3) “simulations” or “re-creations” (detailed and realistic depictions which, in the opinion of the creator, simulate the nature of the events); and (4) “computer models” (compilations of mathematical formulae and expressions integrated into a sophisticated program or series of programs which, then, are translated into graphics explicating the results). To these he added a fifth: “enhanced images,” a classification somewhere between static images and animations. While the enhanced image is for the most part static, it can be manipulated by highlighting, enlarging particular areas, presenting side- by-side, split-screen images, printed commentary or transcripts moving in tandem with the image and/or audio.

Courts had recognized them as useful trial aids but the common view was that such pedagogical devices are not evidence themselves. Judge Weinstein forcefully advocated that pedagogical devices be admitted as evidence, subject, of course, to court control against prejudice and manipulation of the viewer’s subconscious. Since 2004, computer-generated technology has advanced by huge leaps and bounds. Advances in computer-generated graphics now portray imagery so sophisticated, so authoritative, so evocative that the pictorial details can dwarf the testimonial foundation that justifies its admissibility in the first place. Could jurors be so smitten by the informative power of the pedagogical medium that the graphics could be overvalued? Consider, for example, the special effects presented in many successful movies. The viewer’s emotions are rabidly excited by the visual cues and it is the imagery punctuating the dialogue, in large part, that moves the viewer.

On Aug. 6, 2012, the California Supreme Court, in People v. Duenas, 55 Cal. 4th 1, involving the shooting of a deputy sheriff, rejected the “beguilement” argument when it comes to the admissibility of animations illustrating what an expert said had happened. The convicted defendant argued on appeal that the animation gave the prosecution’s case an unjustified “air of technical and scientific certainty,” citing court decisions from other states that juries find such visual evidence uniquely persuasive. Defendant took issue with the “form” of the animation as a visual reenactment that was “likely to beguile the jurors into uncritically accepting the version of events depicted in the animation.” Thus, he argued that the animation tended to give the evidence a “posture of mystic infallibility in the eyes of a jury.”

Admissibility Upheld

Following a preliminary hearing and over objection, the jury was shown a four-minute computer animation as to how the shooting occurred. The trial court gave the jury the following cautionary instruction: “What you’re going to see is an animation based on a compilation of different expert opinions. This is similar to the expert using charts or diagrams to demonstrate their respective opinion. This is not a film of what actually occurred or an exact re-creation. It is only an aid to giving you a view as to the prosecution version of the events based upon particular viewpoints and based upon interpretation of the evidence.”

The animation was a series of mostly still images drawn to give the impression of three-dimensional space. Although the objects and figures in the images rarely move, the viewer’s perspective moves within the images, allowing the viewer to see the objects and figures from different angles. The figures were drawn in generic fashion, their facial features indistinct and expressionless. The viewer’s perspective shifts from where the principals were in relation to the patrol car at the various stages in the sequence. Red lines were used as the bullets’ trajectories with a number of descriptive words or headlines superimposed over the animation. Interspersed with the animation were actual autopsy photos.

The California Supreme Court drew a distinction between computer animations and computer simulations. Animation is merely used “to illustrate an expert’s testimony while simulations contain scientific or physical principles requiring validation. Animations do not draw conclusions; they attempt to recreate a scene or process, thus they are treated like demonstrative aids. Computer simulations are created by entering data into computer models which analyze the data and reach a conclusion.” In other words, a computer animation is demonstrative evidence offered to help a jury understand expert testimony or other substantive evidence. A computer simulation, by contrast, is itself substantive evidence.

Courts have compared computer animations to classic forms of demonstrative evidence such as charts and diagrams that illustrate expert testimony. The animation is admissible if it is a fair and accurate representation of the evidence to which it relates. A trial court’s decision to admit such evidence is reviewed for abuse of discretion. A computer simulation, by contrast, is admissible only after a preliminary showing that any “new scientific technique” used to develop the simulation has gained general acceptance in the relevant scientific community. In Duenas both sides agreed the contested evidence was an animation, not a simulation.

A helpful analysis of the differences between computer animations and computer simulations is found in People v. Douglas, 2016 Colo. App. LEXIS 525 (April 21, 2016), cert. den. Defendant was accused of careless driving and leaving the scene of the accident. The trial court decided that video depictions of the collision were admissible as animations because the state trooper, not the computer’s software, supplied the calculations and opinions that were used to create the videos. The Colorado appellate court upheld the ruling and explained that animations are subject to evidentiary rules applicable to demonstrative evidence whereas computer simulations are subject to the “more rigorous” scientific evidence standard. A complicating factor is that, unlike a witness, an attorney “cannot cross-examine a computer about its conclusions.”

In Mares v. Chrysler Grp., 2015 Cal. App. Unpub. LEXIS 6378 (2d Dist. Sept. 4, 2015), a products liability case, the court allowed an expert’s animation on how a vehicle fire occurred because it concluded that the animation provided an accurate overview of the expert’s opinion. Any inaccuracies were explained when the expert clarified how to interpret the animation.

Probative Value

In Morency v. Annucci, 2017 U.S. Dist. LEXIS 163848 (E.D.N.Y. Sept. 30, 2017), a criminal trial in New York state court ended in a conviction. The defendant petitioned the federal court for a writ of habeas corpus. In the state trial, the prosecutor successfully moved to admit a “computer-generated animated video” depicting a reenactment of the crime as supportive demonstrative evidence. The federal court denied the defendant’s petition and ruled that the animated video was an accepted demonstrative evidence tool. Citing New York decisional law, the federal court said that, as long as the prosecution properly authenticates the animation and establishes that the probative value of the animation outweighs the danger of unfair prejudice, a computer-generated animation is admissible.

In Commonwealth v. Chukwuezi, 475 Mass. 597 (Sup. Jud. Ct. 2016), the court, in a murder trial, denied admission of a computer-generated simulation that was intended to assist the jury in determining the shooter’s height. Some photos from surveillance footage were used by defendant’s expert to depict the shooter as being several inches shorter than defendant. The trial judge conducted a hearing in which she questioned the graphic designer who produced the simulation, an engineer and a forensic photographer who worked for the FBI. The trial judge concluded that the simulation was “hopelessly misleading” and would confuse the jury. The state’s highest court upheld the exclusionary ruling.

A helpful article collecting and cataloguing case law by federal circuit and state decisions is found at V. Webster and F.E. Bourn III, “The Use of Computer-Generated Animations and Simulations at Trial,” Defense Counsel Journal (Oct. 2016). Before launching into their case survey, the authors provide a concise review of important factors such as foundational requirements, objections, cautionary instructions and timeliness.

In her Jan. 3, 2018 post, “Technology in the Courtroom: An Evolving Landscape,” author Anjelica Cappellino observes that attorneys “have been slowly but surely adapting to the digital age and utilizing certain technologies to assist in their case.” She reports that the American Bar Association (ABA) has developed a “buyer’s guide” directory that “provides listings on the latest and most popular products and services which includes everything … .” The ABA has also created the Legal Technology Resource Center, which provides technological resources to their members, “helping attorneys stay updated and informed on not just products and services but also the most ethical and efficient ways to use them.”

As the new technology methods infiltrate the courtrooms, readers may wish to review Jessica Moyeda’s “Courtroom Technology” paper, reviewing the progress already made and likely in the future. An intriguing section near the end of her article discusses the likely “disparities in abilities to afford new courtroom technology.” Then, too, there are the practical problems of training lawyers in the use of courtroom technology and “ethical obligations on being able to competently represent a client.”

Readers interested in the progress towards “High-Technology” Courtrooms can start with the post for the National Center of State Courts by Hon. Herbert B. Dixon Jr., Judge of the District of Columbia Superior Court, entitled, “The Evolution of a High-Technology Courtroom.”


The “Brave New World” of high-technology courtrooms and “techie” lawyers’ appeals to jurors is upon us. The battles over admissibility of computer-generated animations and simulations are but the beginning of the tsunami. The juror is being put into the driver’s seat, so to speak. To some extent, the juror subconsciously may soon “experience” the event. The courts likely will not obstruct technological advances so long as jurors are properly instructed. Thus, it remains the advocate’s role to cope with mesmerizing evidence.