Also known as: burdens of proof · onus probandi · onus
Written by attorneys — see sources below.
A party's duty to prove a disputed assertion or charge. The duty encompasses both the burden of production, which requires introducing sufficient evidence to raise an issue, and the burden of persuasion, which requires convincing the factfinder that the assertion is true by the applicable standard such as preponderance of the evidence or beyond a reasonable doubt.
Brittany Bell suffered a single gunshot wound while hunting with Benito Benitez and Brenda Booth. Both men had negligently fired in her direction, but she could not prove which bullet struck her. The court shifted the burden of proof on actual causation to the defendants, requiring each to show his shot did not cause the injury or face joint liability.
After Bernard Bass died, his son Brendan Burns petitioned to probate a will leaving everything to a caregiver. The caregiver, as proponent, presented evidence of due execution. The son, as contestant, bore the burden of proof to establish lack of capacity or undue influence and failed to meet it.
Bayside Shipping and Brookside Pharmaceuticals each discharged chemicals into a river that combined to destroy Baxter Dynamics' downstream fish farm. Baxter proved the combined discharges caused the loss. Each defendant then bore the burden of proof to show what portion of the harm its discharge caused or remain jointly liable for the whole.
A state university adopted a policy admitting only men to its nursing program. Female applicants challenged the classification. The state bore the burden of proof to supply an exceedingly persuasive justification showing the rule was substantially related to an important objective and could not rely on stereotypes about women.
Brendan Burns sued Bristol Steel after a guardrail collapsed and caused his injuries. He introduced evidence that the guardrail was defectively installed. The company argued another factor caused the collapse. Burns retained the burden of proof on causation and had to persuade the jury that the installation defect was the cause in fact.
Bethany Boyd sued a pharmaceutical company claiming its drug caused her birth defect. The company moved for summary judgment, pointing to the absence of admissible expert evidence linking the drug to the injury. Because Boyd bore the ultimate burden of proof on causation, she had to produce sufficient admissible evidence to create a genuine issue of material fact.
Two minors brought suit against Merrell Dow Pharmaceuticals, claiming they suffered limb reduction birth defects because their mothers had taken Bendectin, a drug prescribed for morning sickness to about 17.5 million pregnant women in the United States between 1957 and 1982. Limb reduction defects occur in fewer than one birth out of every 1000. Scientists do not know the mechanism by which any teratogen causes such defects. The plaintiffs offered testimony from three groups of experts. One group proposed to testify to a statistical link between Bendectin ingestion during pregnancy and limb reduction defects based on reanalyses of published studies that had reported no such association. A second group proposed to testify that Bendectin causes limb reduction defects in humans because it causes such defects in laboratory animals. A third group proposed to testify based on the similarity of Bendectin's chemical structure to other drugs suspected of causing birth defects. The district court granted summary judgment to Merrell Dow after excluding the plaintiffs' expert testimony. The Ninth Circuit affirmed that decision. The Supreme Court granted certiorari, reversed, and remanded for consideration under Federal Rule of Evidence 702. On remand, the Ninth Circuit examined the affidavits and prior trial testimony of the plaintiffs' experts. None of the experts had studied the effect of Bendectin on limb reduction defects before being hired to testify in this or related cases. None had published his work on Bendectin in a scientific journal. The only review their work had received was by judges and juries. Plaintiffs' epidemiological experts made vague assertions of a statistically significant relationship between Bendectin and birth defects but did not state that the relative risk exceeded two. With the exception of Dr. Palmer, the remaining experts were willing to testify only that Bendectin is capable of causing birth defects. Dr. Palmer alone was willing to testify that Bendectin did cause the limb defects in each of the children, based on his review of the plaintiffs' medical records and his conclusion that Bendectin is a teratogen.
The burden of proof consists of the burden of production, which requires a party to introduce enough evidence to raise an issue for the factfinder, and the burden of persuasion, which requires convincing the factfinder that the party's position is correct under the governing standard of proof.
The plaintiff bears the burden of proof on every element of the claim, including that the defendant's tortious conduct caused the harm, unless a special doctrine such as alternative liability shifts the burden on causation to the defendants.
…or overbroad." A physician's abortion conviction was affirmed. In Thompson , n. 2, the court observed that any issue as to the burden of proof under the exemption of Art. 1196 "is not before us." But see Veevers v. State , 172 Tex. Cr. R. 162, 168-169, 354 S. W. 2d 161, 166-167 (1962). Cf. United States v. Vuitch , 402 U. S.…
…routinely released, unless the plaintiff makes special application to continue its seizure, in which event the plaintiff has the burden of proof and persuasion." This limitation on the purpose and length of time for which sequestered property is held, the court concluded, rendered inapplicable the due process requirements…
…offered by Merrell, they also misunderstand the moving party's burden on summary judgment. Because plaintiffs bear the ultimate burden of proof
…Thompson , 394 U. S. 618, 634 (1969). And, once it be determined that a burden has been placed upon a constitutional right, the onus
…fairness, public policy, and probability, as well as judicial economy, presumptions are also useful devices for allocating the burdens of proof between parties. See E. Cleary, McCormick on Evidence 968-969 (3d ed. 1984); see also Fed. Rule Evid. 301 and Advisory Committee Notes, 28 U. S. C. App., p. 685. The presumption of reliance…
The proponent of a will must establish prima facie proof of due execution. The contestant then bears the burden of proof on issues such as lack of capacity, undue influence, fraud, or revocation.
When two or more defendants are negligent toward the plaintiff, the plaintiff suffers a single indivisible harm, and the plaintiff cannot prove which defendant caused the injury, the burden on actual causation shifts to each defendant to prove its conduct was not the cause.
The government must supply an exceedingly persuasive justification showing that the classification is substantially related to an important governmental objective and may not rely on overbroad generalizations about women.