Also known as: expert · expert witness · expert evidence · expert testimony
Written by attorneys · grounded in primary & secondary sources — see below
A witness qualified by knowledge, skill, experience, training, or education who may testify in the form of an opinion. The testimony must be based on sufficient facts or data, the product of reliable principles and methods, and a reliable application of those principles and methods to the facts of the case.
Empire Logistics identified Dr. Elise Everly as a retained expert on supply-chain failures and served her written report. The opposing party then noticed her deposition. Because the report had already been provided, the deposition proceeded without objection under the timing rule.
Emma Erickson sued Evergreen Bank for faulty loan underwriting. She offered an accountant whose experience in banking risk models would explain complex transaction data to the jury. The court admitted the testimony because the specialized knowledge assisted the trier of fact on a disputed issue.
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Edith Eberhardt offered an engineer’s opinion linking a product defect to her injury. The district court excluded the testimony for an analytical gap between the data and the conclusion. On appeal the circuit court reviewed the exclusion only for abuse of discretion.
Elijah Edwards sought to establish paternity. The court ordered genetic testing performed only by a laboratory accredited by the AABB. The results were admitted because the testing method and laboratory satisfied the statutory reliability requirements.
Eileen Epstein retained a chemist to opine on contamination levels. The expert applied accepted testing protocols directly to the site samples. The court admitted the opinion because the principles were reliably applied to the facts of the case.
Edgar Evers was prosecuted for assault. The state’s DNA expert relied on a profile generated by a non-testifying lab solely to explain the foundation of her own opinion. The report was not offered for its truth, so the expert’s testimony did not violate confrontation rights.
A party may depose any expert whose opinions may be presented at trial. If the expert must provide a report, the deposition may occur only after the report is furnished.
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The opinion must rest on sufficient facts or data, employ reliable principles and methods, and reflect a reliable application of those methods to the facts of the case.
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Appellate courts review the decision for abuse of discretion, recognizing the trial court’s gatekeeping role in assessing both reliability and relevance.
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Yes, when the profile is used only to explain the basis of the testifying expert’s opinion and was not prepared primarily to accuse a targeted individual.
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…S. Rep. No. 92-415, p. 5 (1971); H. R. Rep. No. 92-238, p. 8 (1971). As a result, both committees noted the need to obtain “expert assistance” in this area. S. Rep. No. 92-415, supra , at 5; H. R. Rep. No. 92-238, supra , at 8. [^disA-9]: Indeed, two Justices asserted that the Court relied too heavily on the EEOC…