Topic: Expert witness

Diaz v. U.S.:  Expert testimony on “most” people’s mental state does not violate Rule 704(b) – Jackson and Gorsuch suggest ways for defense to use or limit ruling

By Greg Mermelstein, Deputy Director & General Counsel, Missouri Public Defender            Expert testimony that “most” drug couriers know they are transporting drugs does not violate Rule 704(b)’s prohibition on testimony about a defendant’s mental state, because the expert testimony is not about whether the defendant herself had a particular mental state, the U.S. Supreme […]