Demonstrative Evidence Compared to Substantive Evidence

It is important for Illinois trial practitioners to have a firm grasp on the differences in the law between demonstrative and substantive evidence. In an Illinois case, Yanello v. Park Family Dental, 2017 IL App (3d) 140926, the appellate court reversed a plaintiff’s verdict. In that case, the court had ruled that evidence that was claimed to be “demonstrative” was not and was in fact “substantive.”

Demonstrative evidence comes to mind when presenting a witness with a “model” that could be an anatomical diagram, a replica of a human brain, or a toy truck. The purpose of demonstrative evidence at trial is to help explain or illustrate testimony of a witness. Under Illinois Supreme Court Rule 213(f), (g), demonstrative evidence need not be disclosed during discovery. But “demonstrative evidence can be admitted only if it is: (1) relevant, that is it makes the existence of a fact in the case more or less probable; (2) is purely demonstrative when it is not used to support a party’s theory of the case or showed the basis of a witness’ opinion; (3) it is fair in that its probative value substantially outweighs its prejudicial value; and (4) it is accurate in that ‘an accurate portrayal of what it purports to show.’” Sharbono v. Hilborn, 2014 IL App (3d) 120597, ¶¶ 9, 30.

Evidence that is used solely to educate the jury about basic principles in a case is “demonstrative” and, according to Illinois Supreme Court Rule 213 may not be disclosed during discovery. On the other hand, “substantive” evidence is used to: (1) establish the existence or non-existence of a fact relevant to a case; (2) bolster or discredit a party’s theory; or (3) support or undermine an expert’s opinion.

In the Yanello case, an anatomical model was used to show the human upper jaw and lower jaw and from that model, the plaintiff’s expert testified. In the Yanello decision it was found that the plaintiff’s expert merely used models to illustrate or explain his testimony; he did not link the models to plaintiff’s dentition or use them to support his opinion that [the defendant] had violated the standard of care. Thus, [plaintiff’s expert] . . . properly used models as demonstrative evidence, rather than as real evidence. Yanello, Id.

The use of demonstrative evidence although helpful in presenting more complicated issued to a jury cannot cross the line into what some courts would believe to be substantive evidence. When the line between demonstrative and substantive evidence is crossed, the presentation of those facts using the demonstration becomes substantive and the rules of evidence are different.

In the Yanello case, the court found that demonstrative evidence in fact did cross the line to become substantive. In the Yanello trial, the defendants’ expert used a skull model to show the amount of bone available in the upper jaw for the placement of implants. The expert also compared the angle in the exemplar skull to x-rays of the plaintiff, undermining the plaintiff’s experts’ opinion that the implants placed by the defendant were improperly angled.

The same defendants’ experts also used the model skull to show to the jury how an x-ray taken from a particular angle may make it look like implants impinged on the nasopalatine canal and maxillary sinus when they do not.

The appeals panel in the Yanello case found that the skulls could have been demonstrative evidence “if they were used merely to explain the meaning of medical terms or to illustrate the appearance or function of various body parts on an average person’s anatomy.” Yanello, 2017 IL App (3d) 140926 at ¶¶ 34, 36.

The appeals panel ruled that the skulls were used as substantive evidence, “as objects that purportedly had probative value in themselves.” In such a case, since the line was crossed, the defendants could use the skull to trial only if they had previously disclosed the skulls as a basis for their expert’s medical opinions prior to trial pursuant to Supreme Court Rule 213 and had laid a proper foundation for the opinion that the skulls were accurate representations of the plaintiff’s dental anatomy. Since that was not done, the verdict for defendants was reversed.

In brief, the Illinois Appellate Court has drawn a clear line between demonstrative and substantive evidence. Evidence that is solely used to educate the jury about basic principles is demonstrative according to Illinois Supreme Court Rule 213 and does not need to be disclosed during discovery. On the other hand, evidence that is considered substantive is such if it is used to (1) establish the existence or nonexistence of a fact relevant to a case, (2) bolster discredit a party’s theory or (3) support or undermine an expert’s opinion.

It is important for Illinois trial lawyers to understand clearly the distinction. In cases where a party has failed to make discovery disclosure inevitably lose the opportunity to present such evidence when it is considered substantive rather than demonstrative.

If you or a family member has been injured or died as a result of the carelessness or negligence of another, Robert Kreisman of Kreisman Law Offices is prepared to handle your case. Robert Kreisman has more than 40 years of experience handling Illinois jury trials.

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