Saturday, November 14, 2020
Federal Rule of Evidence 704(b) states that
In a criminal case, an expert witness must not state an opinion about whether the defendant did or did not have a mental state or condition that constitutes an element of the crime charged or of a defense. Those matters are for the trier of fact alone.
The recent opinion of the United States Court of Appeals for the Eleventh Circuit in United States v. Boykins, 2020 WL 6441103 (11th Cir. 2020), provides a good example of testimony that violates Rule 704(b).
In Boykins, Jarrett Boykins was charged with two counts of possession of methamphetamine with intent to distribute and five related gun counts. At trial,
When Boykins appealed his conviction and challenged this line of questioning, the State didn't even defend it; instead, as the Eleventh Circuit noted, "The government appears to concede, and we agree, that this testimony by Officer Walker violated Rule 704(b)....The question is whether this error satisfies the remaining prongs of plain error [because he did not object to the questioning]."
That said, the court did not find plain error, instead concluding that there was ample other evidence supporting Boykins's conviction.