Tips for Using Demonstrative Evidence at Trial

Demonstrative evidence—evidence in the form of a representation of an object—is a helpful tool for getting your point across in a trial setting. It can include objects, pictures, models, sounds, or other devices used in a trial or hearing to support facts that the party is trying to prove. Demonstrative evidence can help a judge or jury understand how an injury occurred or could not have occurred, the damage inflicted during the occurrence of the injury, and the reliability of other evidence. It can also be used to help jurors visualize key aspects of a case or understand relevant facts that would otherwise be difficult to comprehend without aid.

Some cases get very complex, and with the pervasive smart technology surrounding us, there is an overload of digital information that can be conveyed to support your case in a trial setting. Below are some tips for using demonstrative evidence in a trial setting.

Tip 1. Not All Visual Evidence Is Demonstrative

Demonstrative evidence usually explains other substantive evidence or testimony. It may be used in the courtroom for illustrative purposes, or it may become an exhibit. Some visual evidence can be both demonstrative and substantive, such as an article of clothing from a crime scene that may connect the defendant to the crime. Exhibits such as maps, photographs, and document enlargements are sometimes called “demonstrative evidence,” although they are, in fact, substantive evidence.

Tip 2. Keep It Short and Simple

Demonstrative evidence should help the jury understand relevant facts that would otherwise be difficult to comprehend without the aid. Try to use simple pictures or symbols to convey the concept. You don’t want to overwhelm the visual exhibit with wordiness. Keep in mind, it is better to have multiple charts, graphs, and timelines where each conveys a single parameter rather than having multiple parameters conveyed in a single chart, graph, or timeline.

Tip 3. Engage the Senses

According to a proverb often attributed to Confucian scholar Xunzi, “I hear and I forget. I see and I remember. I do and I understand.” People process a lot of information through hearing, and we don’t have the best filing system to store the information we hear for when we need to recall it during deliberation. Scientists have studied how the human brain gathers and processes data and estimate how much the average human learns through various senses:

• Sight: 87 percent
• Hearing: 7 percent
• Smell: 3.5 percent
• Touch: 1.5 percent
• Taste 1: percent

Given how much data we process through sight, expecting a jury to rely solely on the testimony they hear is risky and ineffective. There are things you can do to make an impact with your demonstrative evidence, such as employing effective color combinations for emphasis. But don’t be afraid to employ auditory cues as well: Let the jury hear a decedent’s voice, the beeping of a monitoring machine at a patient’s bedside, or the ticking of a metronome to reflect the length of time that a plaintiff experienced a trauma.

Tip 4. Be Careful Blending Demonstrative and Substantive Evidence

Demonstrative evidence that is purely illustrative of testimony may face less critical review by a trial court. However, if it looks more like substantive evidence, a judge may require closer conformance to the Rules of Evidence. It is important to understand the federal and state rules of evidence and how they may be applied to the demonstrative evidence you are trying to use. Particularly important are Federal Rules of Evidence 401 (Test for Relevant Evidence), 402 (General Admissibility of Relevant Evidence), and Rule 403 (Excluding Relevant Evidence for Prejudice, Confusion, Waste of Time, or Other Reasons), along with the analogous state rules. Despite the probative value of a piece of demonstrative evidence, a court may still exclude it because of its unfair prejudice, confusing effect, ability to mislead the jury, or cumulative nature. Winning or losing the evidentiary argument often comes down to the application of Rule 403.

For example, consider the 2012 California Supreme Court case People v. Duenas 55 Cal. 4th 1 (Cal. 2012). Here, the trial court admitted a computer animation that illustrated the expert witness’s opinion of how the shooting of a law enforcement officer occurred. The expert’s opinion of where the shooter was located was partly based on the location of shell casings found at the scene. Defense counsel attacked the animation, claiming it was speculative, creating an improper air of scientific certainty, and cumulative. Ultimately, the California Supreme Court held that “[W]hatever uncertainty may exist as to the actual facts in this case, the animation accurately illustrates the opinions of the prosecution’s experts with regard to how the murder occurred, and that is all it purported to do.” (Id. at 22, emphasis in original.)

Tip 5. Interview the Jury after Trial

Interviewing the jury after trial allows you to learn what demonstrative evidence was effective and what was not. Make certain you understand the local rules regarding communication with a juror. Some courts may prohibit post-trial juror interviews, but some will allow them upon request. If post-trial interviews are allowed, you should use them to your advantage. To better manage your time when setting up a post-trial interview, it may be most efficient to introduce yourself to the jurors, thank them for their service, and ask whether you can contact them later to discuss the case. Some questions you may want to ask include:

• What evidence or arguments were most persuasive? What was the jury’s overall view of the case?
• Were any visual demonstratives especially useful or helpful?
• What aspects of the case consumed the most time during deliberations?

Jim Perdue Sr., a 2022 inductee into the Trial Lawyer Hall of Fame, teaches that a trial “is not a debate over a stack of facts” but rather a contest of stories, and the strongest story will win. The proper use of demonstrative evidence can help ensure that your client’s story is the stronger story.