Are Physically Realistic Animations Overly Prejudicial?


In a previous article, I argued that physical realism (physics-based motion, realistic textures and secondary details, perhaps even sound) makes a forensic animation more credible than an animation that lacks realism. I showed the following example of an animation that contains a high level of physical realism. However, while physical realism may increase the credibility of an animation, some have argued that a high level of realism also makes the animation "overly prejudicial," and therefore, such an animation should be excluded. 

Why would an animation be overly prejudicial? Maybe the jurors' ability to reason will be overwhelmed by the emotions evoked by the animation. 

Graves [2000] expressed this concern as follows: "With respect to how Rule 403 may exclude a proposed trial exhibit, consider a photograph of dead victims at a crime scene in a murder case. Although such a photograph would contain some probative value because it would show where and how the bodies were situated, such a photograph alsowould display the graphic and blood image of the actual bodies of the murder victims as they were found. Thus, the photograph, although relevant, would present a danger of horrifying the members of the jury or inflaming their passions so that they might be more likely to convict this, or any, defendant, based more on emotion and hostility rather than on fact and logic. In such circumstances, at least one court has held that the probative value of such a 'bloody crime scene' photograph is substantially outweighed by the danger of unfair prejudice pursuant to Rule 403. The same concern for unfair prejudice is present when the trial exhibit is a [computer generated exhibit], rather than just a photograph or chart, because the [computer generated exhibit] itself, especially an animation or re-creation, may be so powerful or overly suggestive that it might pose a danger that its probative value is substantially outweighed by the danger of unfair prejudice" (emphasis added).

But, hey, jurors are smarter than that!

Graves argues that this concern is unwarranted, noting that "the apparent concern that jurors lose all sense of reality and simply believe anything and everything they see depicted on a television or computer screen presupposes a certain naiveté and basic lack of intelligence on the part of juries that is not only unwarranted as a matter of psychological research, but is also offensive and even elitist. Although 'the masses' - which include all potential jurors - watch television and go to movies, most are able to distinguish reality from fantasy, and those who cannot do so can and should be identified and excused during the voir dire the extent that a typical juror has ever seen a movie or television program with special effects, and therefore probably understands that not all of the images displayed therein are necessarily portraying actual events, such a juror presumably would also understand that images can be manipulated at trial to depict things, such as a witness's testimony, which ultimately may or may not be true. We should respect the ability of jurors to make up their own minds." 

Principle #7 from my previous article - present the production process in a transparent way - also helps to address any concern that jurors will be fooled by what they are watching. As I stated in that article: "While physical realism can add credibility to an animation, a jury should not be left with the impression that they are actually watching the real events. Animations are often a demonstrative exhibit that illustrates an expert’s opinions. A transparent presentation of the process through which the animation was created will help the jury understand the accident better, but will not leave them with a misunderstanding of what they are actually watching. By a transparent presentation, here’s what I mean: present the physical evidence, present your analysis of the physical evidence, present how you have brought principles of physics to bear on the physical evidence, and then present how physical evidence and physics flow directly into the animation."

Not only that, animations can increase the jury's level of engagement and attention, increasing the likelihood jurors will retain key facts about the case.  

Graves has observed that "visual information aids juries in three specific ways that are extremely useful, if not essential. The first is that information must be imaginable to be assimilated and believed, which means that it must prompt sensory imagery. Oral testimony using abstract, technical or nebulous not exactly the most easily conveyed or most concrete explanatory language and therefore usually fails to convey sufficient information to the jury...The second way visual information aids juries is proximity. Proximity indicates how close the information and data is to the jury; that is, how many mental steps the jury must take to understand the information being presented...humans assimilate information mentally at a much faster rate [when it is communicate with images rather than when] it is verbally expressed...finally, visual information is easier for the human mind to remember...Using visual information is not illegitimate manipulation of the jury; instead it is merely getting them to do their very legitimate function better - remembering what happened at trial in order to render the best verdict possible."

Graves also observes that "there is no rule that an attorney is prohibited from being 'too illustrative,' or an expert witness 'too credible' in his or her presentation, so long as what is being presented has met the foundational requirement of being a fair and accurate portrayal of the expert's testimony. To combat an objection on these grounds, it must be pointed out that it is the expert's testimony behind the animation that should be the issue, not merely the means by which that testimony is portrayed. Simply because one side uses sophisticated graphics to help explain its case while the other side uses amateur crayon drawings or, worse yet, no visual aids at all for its exhibits, does not render the sophisticated graphics unfairly prejudicial."

In the end, it's all about offering the jury value.

In considering the admissibility of an animation, a judge will need to weigh the value the animation offers to the jury against the potential that it will be "overly prejudicial." As long as the danger of unfair prejudice doesn't substantially outweigh the probative value, the animation will be admissible. And so, if an animation is produced and explained in a way that genuinely helps the jury to understand the issues in the case, there will be a high likelihood the that animation will be admitted.


  1. Galves, Fred, "Where the Not-So-Wild Things Are: Computers in the Courtroom, The Federal Rules of Evidence, and the Need for Institutional Reform and More Judicial Acceptance," Harvard Journal of Law and Technology, Volume 13, Number 2, Winter 2000.