When is an Expert Testifying to a Legal Conclusion?

The legal profession is over dependent upon expert witnesses.  When is a witness’s opinion merely a party’s legal conclusion that the witness was hired to give?  What is allowed and what isn’t?  The Supreme Court considered this question this month.

Pundyk v. State was a criminal matter where the defendant shot and killed his mother.[1]  His defense was insanity and he planned to offer a medical expert, Melissa Piasecki, M.D., to testify “that Pundyk was unable to appreciate that his conduct was wrong.”  This is part of an insanity defense.  The State moved to exclude Dr. Piasecki and the motion was granted in part.

Dr. Piasecki could not provide a conclusion about Pundyk’s mental state or his guilt or innocence. However, the district court permitted Dr. Piasecki to opine about Pundyk’s ability to form intent at the time of the offense. During trial, the district court sustained the State’s objections to two of Pundyk’s questions to Dr. Piasecki regarding Pundyk’s ability to understand his actions and form a specific plan. Ultimately, the district court allowed Dr. Piasecki to testify that Pundyk “was so disconnected from reality at the time” that “he was not able to form the requisite intent.” The jury found Pundyk guilty but mentally ill on both charged offenses

The Supreme Court acknowledged “that our decisions regarding psychiatric expert witness testimony on the ultimate issue of mental states have been somewhat incongruous and take this opportunity to reconcile those decisions.”  The analysis focused upon NRS 50.295, which “expressly permits an expert witness to testify about ultimate issues within their area of expertise.”

NRS 50.295 expressly allows expert witnesses to proffer testimony that embraces ultimate issues so long as the testimony is otherwise admissible. The otherwise admissible portion of NRS 50.295 is a reference to Nevada’s evidence code. Therefore, unless there is an independent basis under Nevada’s evidence code for precluding expert witness testimony, an expert witness may proffer testimony that embraces ultimate issues. NRS 50.275 permits expert witnesses to “testify to matters within the scope of” their expertise so long as that testimony “will assist the trier of fact to understand the evidence or to determine a fact in issue.” (Emphases added.)

Applying this analysis, the Court added “expert witness testimony that amounts to a legal conclusion is not admissible because it does not help the trier of fact “understand the evidence or “determine a fact in issue.”  What is the distinction then between acceptable testimony that assists the jury and an impermissible legal conclusion?  As applied to the facts of this particular case, “a qualified expert witness may testify regarding whether the defendant meets the elements of the not-guilty-by-reason-of-insanity plea under NRS 174.035(6). Such testimony is factual in nature and helps the trier of fact determine whether the defendant meets that standard.”  Conversely, “a qualified expert witness may not offer a direct opinion on the ultimate conclusion that a defendant is not guilty by reason of insanity or the converse. Such testimony is tantamount to a legal conclusion and is not proper under NRS 50.275.”

At first glance, this seems to be a thin distinction, but one that litigants will have to address.


[1] 136 Nev. Adv. Op. 43 (2020).