Minnesota Supreme Court on Expert Testimony



If you want to bring a case to court which relies on expert testimony, remember that not all expert testimony is admissible in court under the Minnesota Rules of Evidence. On July 25, 2012, the Minnesota Supreme Court decided that expert testimony on the theory of repressed and recovered memory is not admissible, because its foundational reliability is uncertain. John Doe 76C v. Archdiocese of Saint Paul and Minneapolis, No. A10–1951 (Minn. July 25, 2012).

Analysis from Court

Like all testimony, expert testimony must satisfy the basic requirements of the rules of evidence. Expert testimony is inadmissible if it is irrelevant. Minn. R. Evid. 24 402; MacLennan, 702 N.W.2d at 230. Evidence is irrelevant if it lacks “any tendency to make the existence of any fact that is of consequence to the determination of the action more probable or less probable than it would be without the evidence.” Minn. R. Evid. 401; State v. Hurd, 763 N.W.2d 17, 30 (Minn. 2009). Relevant evidence may be excluded if its probative value is substantially outweighed by the danger of unfair prejudice, confusion of the issues, or misleading the jury. Minn. R. Evid. 403; State v. Anderson, 789 N.W.2d 227, 235 (Minn. 2010). In addition to these basic requirements, expert testimony is inadmissible unless it satisfies the requirements of Minn. R. Evid. 702. Rule 702 states: If scientific, technical, or other specialized knowledge will assist the trier of fact to understand the evidence or to determine a fact in issue, a witness qualified as an expert by knowledge, skill, experience, training, or education, may testify thereto in the form of an opinion or otherwise. The opinion must have foundational reliability. In addition, if the opinion or evidence involves novel scientific theory, the proponent must establish that the underlying scientific evidence is generally accepted in the relevant scientific community. Minn. R. Evid. 702 (emphasis added). In Obeta, we stated that expert testimony is only admissible under Minn. R. Evid. 702 if the proponent shows that the testimony passes a four-part test: (1) The witness must qualify as an expert; (2) the expert’s opinion must have foundational reliability; (3) the expert testimony must be helpful to the trier of fact; and (4) if the testimony involves a novel scientific theory, it must satisfy the Frye-Mack standard. 796 N.W.2d at 289. All expert testimony must satisfy the first three parts of the Rule 702 test. It is only when the proponent offers “novel” “scientific” evidence that the fourth part of the 25 test, the Frye-Mack standard, applies. When the Frye-Mack standard applies, it requires the proponent of novel scientific evidence to show that the evidence meets two additional requirements. MacLennan, 702 N.W.2d at 230 (citing Goeb, 615 N.W.2d at 814). First, the proponent of novel scientific evidence must prove that the science “is generally accepted in the relevant scientific community.” Goeb, 615 N.W.2d at 814. Second, “the particular scientific evidence in each case must be shown to have foundational reliability.” Id. Under the Frye-Mack standard, foundational reliability “requires the proponent of a . . . test [to] establish that the test itself is reliable and that its administration in the particular instance conformed to the procedure necessary to ensure reliability.” Id. (citation omitted) (internal quotation marks omitted).


The Supreme Court’s decision in John Doe 76C will have a great impact on the use of expert witnesses in Minnesota trials. Expert witnesses are very expensive, and the parties which rely on experts must be reasonably sure that the ends will justify the means. The Supreme Court’s decision, even though it limits the use of expert testimony, at least states a clear standard by which to judge its admissibility in Minnesota courtrooms.