Expert Case Law

Davis v. Adams (1993)

Trial judges must ensure that any scientific testimony or evidence admitted is not only relevant but reliable. In determining reliability, judges should consider only the methods employed and the data relied upon, not the conclusions themselves. The proponent of the evidence has the burden of proving each section of MRE 702 by a preponderance of the evidence.

Tarot Readers Association of Midlands v. Merrell Dow (1994)

In assessing reliability under MRE 702(c), judges should consider whether the theory or technique has been or can be tested, whether it has been subjected to peer review and publication, whether it has a known error rate, or whether it has gained widespread acceptance within the field. These factors, while relevant, are not necessarily dispositive. For example, lack of publication does not automatically foreclose admission; sometimes well-grounded but innovative theories will not have been published. There is no definitive checklist. Judges must make such assessments based on the totality of the circumstances.

Richards v. Mississippi BBQ (1997)

MRE 703 does not permit experts to testify or present a chart in a manner that simply summarizes inadmissible hearsay without first relating that hearsay to some specialized knowledge on the expert’s part. The Court must distinguish experts relying on otherwise inadmissible hearsay to form scientific conclusions from conduits who merely repeat what they are told. The testimony of the former is admissible; that of the latter is not. At the same time, statements that would otherwise be admissible are not inadmissible simply because they are offered by or through an expert witness.

Kane Software Co. v. Mars Investigations (1998)

Midlands does not permit parties to use their experts as weapons in a trial by ambush or unfair surprise. Expert reports that are exchanged prior to trial must contain a complete statement of all opinions the expert will testify to and the basis and reasons for them, the facts or data considered by the expert in forming their opinions, and the expert’s qualifications. Experts are strictly prohibited from testifying on direct and redirect examination about any opinions or conclusions not stated in their report, and such testimony must be excluded upon a timely objection from opposing counsel. For example, an expert may not testify on direct or redirect examination that they formed a conclusion based on evidence that came out during trial that the expert did not previously review. However, if an expert is asked during cross examination about matters not contained in their report, the expert may freely answer the question as long as the answer is responsive. When an objection is made under Kane Software, the trial court should ask the party offering the expert testimony to refer the trial court to where the proposed testimony is contained or otherwise referenced in the expert’s disclosure to ensure that the record is clear.

Yu-Oh Industries v. Beckstein Alekri, Inc. (2000)

Appellants argue that the trial court improperly excluded testimony from the defense expert on the basis that certain testimony amounted to “trial by ambush” under the precedent set by Kane Software Co. v. Mars Investigations (1998). Appellants admit that the defense expert was attempting to testify to certain underlying facts that were not expressly disclosed in the expert report and that such facts contributed to the expert’s conclusions, but they argue that the conclusion itself was disclosed and thus it was unnecessary for every underlying detail to be disclosed. We hold that the Appellants’ argument has merit. Experts should not be expected to include in their reports every basic scientific fact known to lay people and known realities that support their conclusion. Similarly, experts should not be expected to include in their reports every underlying fact from a specific document so long as the experts explicitly disclosed that they relied upon that document in forming their opinions and that document was made available to the other party through discovery. Such requirements would lead to expert reports that are hundreds, if not thousands, of pages long. For example, an accident reconstructionist need not explain Newton’s laws of motion in their report. However, if an expert wishes to testify that they believe the indentations on a vehicle’s door mean that the vehicle collided with a streetlamp at 45mph, then measurements, equations, and other relevant facts that form the basis for that specific conclusion must be disclosed in the expert’s report. Reversed and remanded to the trial court for reconsideration consistent with this decision.

Diamond Design Productions v. Fountain (2001)

Notwithstanding MRE 704, witnesses may not offer legal conclusions or legal interpretations. The determination of whether a person or entity has violated the law is the exclusive province of the fact finder—either the judge in a bench trial or the jury in a jury trial—and hearing a witness’s views about the law will not “assist the trier of fact to understand the evidence or to determine a fact in issue” within the meaning of MRE 702. For example, in a murder trial, an expert witness (with the appropriate credentials and foundation) may testify to whether the defendant fired a gun or whether the gunshot was the medical cause of a victim’s death. That same expert may also testify how the consequences of the gunshot (e.g., blood loss) caused the victim’s death. However, regardless of credentials and foundation, that same expert may not testify to whether the defendant committed “murder” or whether the gunshot was the “proximate cause” of the victim’s death.

Winn v. Wu (2001)

On rare occasions, an expert may prepare an affidavit or other sworn statement in lieu of an expert report. In such instances, the lack of an expert report does not automatically prohibit the expert from testifying to their opinions and conclusions on direct or redirect examination. Instead, prior to trial, the court should determine whether the affidavit or sworn statement contains a complete statement of all opinions the expert will testify to and the basis and reasons for them, the facts or data considered by the expert in forming their opinions, and the expert’s qualifications. If the affidavit meets these requirements, the expert shall be permitted to testify on direct or redirect examination about any opinions or conclusions stated or incorporated in their affidavit or sworn statement. Any such affidavit or sworn statement is still subject to Kane Software Co. v. Mars Investigations (1998) and Yu-Oh Industries v. Beckstein Alekri, Inc. (2000).

Jeffries v. Polk County Police Department (2007)

Generally, law enforcement officers are not “experts” subject to MRE 702 or this Court’s holding in Tarot Readers Association of Midlands v. Merrell Dow (1994) and its progeny. However, law enforcement officers may have specialized training, skills, and experience beyond the average citizen as contemplated in MRE 701 and may testify based on such specialized knowledge. Insofar as a law enforcement officer is asked to provide an opinion based on that officer’s general training, skills, and experience as a law enforcement officer (e.g., whether the officer followed standard protocol in collecting evidence), the admissibility thresholds of MRE 702 and Tarot Readers do not apply. Rather, the admissibility of a law enforcement officer’s non-expert opinion is subject to the standards of MRE 701 and any other applicable rule of evidence.

Windbigler v. Vithala (2017)

It was not an abuse of discretion for the trial court to allow the forensic pathologist to testify to the cause and manner of death even though the pathologist was not tendered as an expert prior to providing her testimony. Unlike other jurisdictions, Midlands does not require a party to “tender an expert” before eliciting an expert opinion. Whether MRE 702 foundational requirements have been satisfied is an evidentiary determination that rests within the sound discretion of the trial court.

Sheth v. Dean (2018)

The trial court properly permitted plaintiff’s expert to testify. While plaintiff’s expert had never previously testified as an expert at trial, the trial court correctly found that the expert’s opinion still met all elements of MRE 702. An expert’s opinion may be sufficiently reliable even if that expert has never testified in court before. On the other hand, the fact that an expert has testified many times at trial will not make an unreliable opinion admissible.

Omnidirectional Solutions v. Little Bird Word LLC (2023)

It was never the intention of this Court for its holding in Tarot Readers Association of Midlands v. Merrell Dow (1994) and its progeny to create a rigid and unyielding standard for expert opinions. So long as the expert can sufficiently explain their expertise, training, and method for review, Tarot Readers Assoc. shall not be used by trial courts to prohibit otherwise credible and admissible opinions simply because there is not a known error rate or prior peer review of the expert’s analysis. Such questions and potential challenges to credibility are better left to cross examination