In almost every legal proceeding, the parties are required to adhere to important rules known as evidentiary standards and burdens of proof. These rules determine which party is responsible for putting forth enough evidence to either prove or defeat a particular claim and the amount of evidence necessary to accomplish that goal.

The Burden of Proof

The burden of proof determines which party is responsible for putting forth evidence and the level of evidence they must provide in order to prevail on their claim. In most cases, the plaintiff (the party bringing the claim) has the burden of proof.

The burden of proof has two components. First, the plaintiff must satisfy the burden of production, which has also been referred to as the burden of going forward. As the terms suggest, this burden requires the plaintiff to put forth evidence in the form of witness testimony, documents, or objects. After the plaintiff presents his or her case-in-chief, the burden of production shifts to the defendant, who then has the opportunity to provide evidence either rebutting the plaintiff’s evidence or supporting the defendant’s own arguments.

Evidentiary Standards in Civil Cases

Second, the plaintiff must satisfy the burden of persuasion. This burden determines which standard of proof the plaintiff must follow in presenting evidence to the judge or jury. A standard of proof determines the amount of evidence the plaintiff or defendant needs to provide in order for the jury to reach a particular determination. In most civil cases, the burden of persuasion that applies is called “a preponderance of the evidence.” This standard requires the jury to return a judgment in favor of the plaintiff if the plaintiff is able to show that a particular fact or event was more likely than not to have occurred. Some scholars define the preponderance of the evidence standard as requiring a finding that at least 51 percent of the evidence favors the plaintiff’s outcome.

In some civil cases, the burden of proof is elevated to a higher standard called “clear and convincing evidence.” This burden of proof requires the plaintiff to prove that a particular fact is substantially more likely than not to be true. Some courts have described this standard as requiring the plaintiff to prove that there is a high probability that a particular fact is true. This standard sets a higher threshold than the preponderance of the evidence standard, but it does not quite rise to the widely recognized standard used in criminal cases, known as “beyond a reasonable doubt.”

In administrative law proceedings, the standard of proof that most commonly applies is the substantial evidence standard. This standard requires the plaintiff or moving party to provide enough evidence that a reasonable mind could accept as adequate to support a particular conclusion.

Evidentiary Standards in Criminal Cases

The “beyond a reasonable doubt” standard is the highest standard of proof that may be imposed upon a party at trial, and it is usually the standard used in criminal cases. This standard requires the prosecution to show that the only logical explanation that can be derived from the facts is that the defendant committed the alleged crime, and that no other logical explanation can be inferred or deduced from the evidence. The United States Supreme Court in Victor v. Nebraska, 511 U.S. 1 (1994), described this standard as “such doubt as would give rise to a grave uncertainty, raised in your mind by reasons of the unsatisfactory character of the evidence or lack thereof . . . . What is required is not an absolute or mathematical certainty, but a moral certainty.”

In the criminal law context, there are a few additional standards that apply in specific circumstances. Another well-known standard is the probable cause standard. This standard focuses on balancing effective law enforcement practices against the Fourth Amendment guarantee against unreasonable invasions into citizens’ privacy. In Illinois v. Gates, 462 U.S. 213 (1983), the Supreme Court outlined the totality of the circumstances test that applies to determining whether a police officer had probable cause to conduct a search and seizure, and for magistrate judges to use when issuing warrants. The standard requires police officers and judges “to make a practical, common-sense decision whether, given all the circumstances set forth in the affidavit before him, including the ‘veracity’ and ‘basis of knowledge’ of persons supplying hearsay information, there is a fair probability that contraband evidence of a crime will be found in a particular place.”

Other standards used to evaluate evidence in the criminal context include reasonable belief and reasonable suspicion. Any police actions that are subject to these standards of proof must be based on grounds that are reasonable in light of the circumstances. Stated differently, a reasonable suspicion occurs when a police officer “observe[s] unusual conduct which lead him reasonably to conclude in light of his experience that criminal activity may be afoot and that the persons with whom he is dealing with may be armed and dangerous . . . .” Terry v. Ohio, 392 U.S. 1 (1968).

Another common standard of proof used in some criminal law proceedings is the credible evidence standard. Credible evidence is evidence that is not necessarily true but that is worthy of belief and worthy of the jury’s consideration. Some have defined this standard as requiring the jury to conclude that the evidence is natural, reasonable, and probable in order for it to be credible.

Last updated May 2019