Also known as: FRE 702 · Rule 702 · Fed. R. Evid. 702 · Federal Rules of Evidence 702
Written by attorneys · grounded in primary & secondary sources — see below
A rule of evidence that authorizes a witness qualified by knowledge, skill, experience, training, or education to offer opinion testimony. The proponent must demonstrate that the testimony rests on sufficient facts or data, employs reliable principles and methods, applies those principles and methods reliably to the case facts, and will assist the trier of fact to understand the evidence or resolve a factual issue.
DataShield Inc. offers Dr. Rivera to explain how NimbusCloud's encryption was likely breached using a self-created algorithm never tested outside his lab. The court excludes the testimony because the method rests on specialized knowledge that must satisfy Rule 702 reliability standards rather than qualifying as lay perception. NimbusCloud's motion succeeds and the jury never hears the opinion.
Frederick Ferguson sues General Electric after developing lung disease allegedly from workplace PCBs. His experts rely on animal studies and epidemiological data that the trial court finds too attenuated to support causation. The Supreme Court affirms exclusion, holding that the district judge properly exercised gatekeeping discretion over the experts' conclusions.
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Fatou Fall and other parents sue Merrell Dow claiming the drug Bendectin caused limb defects. Their experts cite unpublished reanalyses and animal studies never subjected to peer review. The Supreme Court holds that the trial court must evaluate whether the methodology is scientifically valid before admitting the testimony.
Flora Ford is prosecuted for assault and offers a psychologist to testify about factors affecting eyewitness reliability. The government objects that the testimony invades the jury's role. The Supreme Court upholds the trial court's authority to admit the evidence after confirming its relevance and reliability under the governing evidence rule.
Finn Fletcher sues Kumho Tire after a tire blowout causes an accident. His expert relies on visual inspection and experience-based conclusions about manufacturing defects. The Supreme Court confirms that the gatekeeping obligation applies to all specialized knowledge, not merely laboratory science, and that the trial court may exclude the testimony after a flexible reliability inquiry.
The judge acts as gatekeeper and must ensure that expert testimony is both relevant and reliable before it reaches the jury. Reliability turns on whether the expert's principles and methods are trustworthy and were reliably applied to the facts.
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No. The rule covers all testimony based on scientific, technical, or other specialized knowledge, including engineering, construction safety, and agricultural expertise. Courts must conduct a flexible reliability inquiry regardless of the field.
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The proponent must demonstrate that it is more likely than not the expert is qualified, the testimony rests on sufficient facts or data, the methods are reliable and reliably applied, and the specialized knowledge will help the trier of fact.
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Lay opinion is inadmissible if it rests on scientific, technical, or other specialized knowledge within the scope of Rule 702. Testimony that requires expertise must satisfy the qualification, reliability, and helpfulness requirements of Rule 702 rather than the more limited Rule 701 standards.
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…an inference or assertion must be derived by the scientific method." Id. Elsewhere in its opinion, the Court noted that Rule 702 is satisfied where the proffered testimony is "based on scientifically valid principles." Id. at ----, 113 S.Ct. at 2799. Our task, then, is to analyze not what the experts say, but what…