Follow Up: Demonstrative vs. Substantive Evidence

Updated: May 30, 2019

A follow up to my previous blog post on demonstrative vs. substantive evidence. In a recent South Carolina Supreme Court case, Hamrick v. State, Justice Few explained a real life scenario how demonstrative and substantive evidence vary in their application.

In a nutshell, an expert testified for the defense on accident reconstruction. He had created a video of the accident to explain that the defendant did not do what the State said that he did. The judge allowed the testimony but excluded the video from being admitted as evidence.

At first reading, I thought that this was perfectly acceptable because the video was merely demonstrative evidence that the expert used to help illustrate to the jury what he was testifying to. And that the judge properly used Rule 611 to determine that the video would not go into evidence. But as Justice Few pointed out, this was not demonstrative evidence, but rather it was substantive. And because it was substantive evidence, then the judge must follow the rules of evidence when deciding if it should be excluded (Rules 401, 402, 403, etc.).

A good rule of thumb that comes out of this case: Typically, results of experiments are substantive evidence.