Burden of Proof
A duty placed upon a civil or criminal defendant to prove or disprove a disputed fact.
Burden of proof can define the duty placed upon a party to prove or disprove a disputed fact, or it can define which party bears this burden. In criminal cases, the burden of proof is placed on the prosecution, who must demonstrate that the defendant is guilty before a jury may convict him or her. But in some jurisdiction, the defendant has the burden of establishing the existence of certain facts that give rise to a defense, such as the insanity plea. In civil cases, the plaintiff is normally charged with the burden of proof, but the defendant can be required to establish certain defenses.
Burden of proof can also define the burden of persuasion, or the quantum of proof by which the party with the burden of proof must establish or refute a disputed factual issue. In criminal cases, the prosecution must prove the defendant's guilt BEYOND A REASONABLE DOUBT.
Judges explain the REASONABLE DOUBT STANDARD to jurors in a number of ways. Federal jury instructions provide that proof beyond a reasonable doubt is "proof of such a convincing character that a reasonable person would not hesitate to act upon it in the most important of his own affairs." State judges typically describe the standard by telling jurors that they possess a reasonable doubt as to the defendant's guilt if, based on all the evidence in the case, they would be uncomfortable with a criminal conviction. In giving the reasonable doubt instruction, judges regularly remind jurors that a criminal conviction imposes a variety of hardships on a defendant, including public humiliation, incarceration, fines, and occasionally the FORFEITURE of property. Reasonable doubt is the highest standard of proof used in any judicial proceeding.
Reasonable doubt is also a constitutionally mandated burden of proof in criminal proceedings. The U.S. Supreme Court has ruled that the DUE PROCESS CLAUSE of the FIFTH AMENDMENT and Fourteenth Amendments to the federal constitution prohibit criminal defendants from being convicted on any quantum of evidence less than proof beyond a reasonable doubt. IN RE WINSHIP, 397 U.S. 358, 90 S. Ct. 1068, 23 L. Ed. 2D 368 (1970). Although the reasonable doubt standard is not specifically mentioned anywhere in the Constitution, the Court observed that the standard is so deeply rooted in the nation's history as to reflect the fundamental value that "it is far worse to convict an innocent man than to let a guilty man go free."
In civil litigation the standard of proof is either proof by a PREPONDERANCE OF THE EVIDENCE or proof by clear and convincing evidence. Both are lower burdens of proof than beyond a reasonable doubt. A preponderance of the evidence simply means that one side has more evidence in its favor than the other, even by the smallest degree. Clear and convincing evidence is evidence that establishes the truth of a disputed fact by a high probability. Criminal trials employ a higher standard of proof because criminal defendants often face the deprivation of life or liberty if convicted while civil defendants generally only face an order to pay money damages if the plaintiff prevails.
Scheibe, Benjamin D. 2003. "Claim of Reverse Engineering Doesn't Alter Burden of Proof." The Los Angeles Daily Journal 116 (October 2).
Twining, William and Stein, Alex, eds. 1992. Evidence and Proof. New York: New York University Press.