In a civil case, the plaintiff has the burden of proving the facts and claims asserted in the complaint. If the respondent, or defendant, files a counterclaim, the respondent will have the burden of proving that claim. When a party has the Burden of Proof, the party must present, through testimony and exhibits, enough evidence to support the claim. The amount of evidence required varies from claim to claim. For most civil claims, there are two different evidentiary standards: preponderance of the evidence, and clear and convincing evidence. A third standard, proof Beyond a Reasonable Doubt, is used in criminal cases and very few civil cases.
The quantum of evidence that constitutes a preponderance cannot be reduced to a simple formula. A preponderance of evidence has been described as just enough evidence to make it more likely than not that the fact the claimant seeks to prove is true. It is difficult to translate this definition and apply it to evidence in a case, but the definition serves as a helpful guide to judges and juries in determining whether a claimant has carried his or her burden of proof.
The majority of civil claims are subjected to a preponderance of evidence standard. If a court or legislature seeks to make a civil claim more difficult to prove, it may raise the evidentiary standard to one of clear and convincing evidence.
Under some circumstances use of the low preponderance of evidence standard may be a violation of constitutional rights. For example, if a state seeks to deprive natural parents of custody of their children, requiring only proof by a preponderance of evidence is a violation of the parents' due process rights (Santosky v. Kramer, 455 U.S. 745, 102 S. Ct. 1388, 71 L. Ed. 2d 599 [1982]). Freedom in matters of family life is a fundamental liberty interest, and the government cannot take it away with only a modest evidentiary standard. However, a court may use a preponderance of evidence standard when a mother seeks to establish that a certain man is the father of her child (Rivera v. Minnich, 483 U.S. 574, 107 S. Ct. 3001, 97 L. Ed. 2d 473 [1987]). Most states use the preponderance of evidence standard in these cases because they have an interest in ensuring that fathers support their children.
Further readings Orloff, Neil, and Jery Stedinger. 1983. "A Framework for Evaluating the Preponderance-of-the-Evidence Standard." University of Pennsylvania Law Review 131 (April).
Slatkin, Stephanie. 1997. "The Standard of Proof at Sentencing Hearings Under the Federal Sentencing Guidelines: Why the Preponderance of the Evidence Standard is Constitutionally Inadequate."
Cross-references Clear and Convincing Proof.