Allow Me To Demonstrate: California Case Reveals Lack Of Standards Governing Admissibility of Demonstrative Evidence

In contrast to testimonial or documentary evidence, demonstrative evidence is "principally used to illustrate or explain other testimonial, documentary or real proof, or judicially noticed fact. It is, in short, a visual (or other) sensory aid." A diagram of the scene of a crime drawn on a board by a percipient witness who is present at trial to testify would be classic demonstrative evidence. Whereas the diagram illustrates the witness' testimony, it should, technically speaking, add nothing further. In this way and despite its title as "evidence," demonstrative evidence is more of a visual aid than evidence per se because it merely illustrates or "demonstrate[s]" a witness' testimony. Jessica M. Silbey, Judges as Film Critics: New Approaches to Filmic Evidence, 37 U. Mich. J.L. Reform 493, 503 (2004).

Perhaps the most (in)famous example of demonstrative evidence was the failed glove experiment in the O.J. Simpson trial. But what standards governs the admissibility of demonstrative evidence? As the recent opinion of the Court of Appeal, Third District, California, in People v. Bonde, 2009 WL 4264324 (Cal.App. 3 Dist. 2009), makes clear, the answer is "not many." 

In Bonde, a jury convicted David James Bonde of first degree murder, and found that the murder was committed to avoid arrest, in the commission or attempted commission of a robbery, and in the commission or attempted commission of a carjacking. This conviction was based upon evidence of the following being presented at trial:

Early Christmas morning, 2006, after a night of drinking and smoking methamphetamine, [Bonde]'s friends dropped him off near his sister's house....He was walking down Virginia Street around 2:00 or 3:00 a.m. when he spotted an older model white Chevrolet pickup. He decided to hot wire the pickup. He used a knife he had just purchased to cut the wires and start the pickup.

The pickup belonged to Ryan Gomes, who lived on Virginia Street with Amy Campbell and their son Clayton. The family was awakened by the loud noise of the truck when [Bonde] started it. When Gomes realized someone was taking his truck, he ran outside, still wearing his pajamas. The truck stalled, and Gomes ran up to the truck window and asked [Bonde] why he...was stealing his truck. He told [Bonde] the police were on their way.

[Bonde] got out of the truck, took the knife from between his teeth, stepped toward Gomes, and said, "Come on" and "What are you going to do about it?" [Bonde] attacked Gomes with the knife, stabbing him three times in his chest and once in his back. Gomes died of shock and hemorrhage due to multiple stab wounds.

After [Bonde] was arrested, he gave several videotaped interviews to the police, in which he admitted to stabbing Gomes.

In addition to testimonial and documentary evidence, the prosecution presented demonstrative evidence. Specifically, the prosecution 

informed the trial court that he had a rubber knife that was approximately the same size as the knife [Bonde] used to stab Gomes, and that he intended to have [Bonde] show how he used the knife against Gomes. Defense counsel objected that the demonstration with the rubber knife would be inflammatory because it would cause the jury to “envision” and "reliv[e]" the murder.

The trial court overruled the objection, and the Court of Appeal subsequently affirmed, finding that

Demonstrative evidence is admissible despite some prejudicial effect as long as it "'tends to prove a material issue or clarify the circumstances of the crime.'"...The demonstration here was admissible despite the slight prejudicial effect of seeing defendant reenact the murder because it clarified the circumstances related to the claimed defense. In short, the evidence was not more prejudicial than probative, and the trial court did not abuse its discretion in admitting the evidence.

-CM