Burden of proof
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Burden of proof (Latin, onus probandi) is the obligation to prove allegations which are presented in a legal action. Under the Latin maxim necessitas probandi incumbit ei qui agit, the ordinary rule is that "the necessity of proof lies with he who complains." For example, a person has to prove that someone is guilty (in a criminal case) or liable (in a civil case) depending on the allegations; a person is not required to prove his or her own innocence, it is rebuttably presumed. More colloquially, burden of proof refers to an obligation in a particular context to defend a position against a prima facie other position.
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[edit] Types of burden
There are generally three broad types of burdens:
- A "legal burden" or a "burden of persuasion" is an obligation that remains on a single party for the duration of the claim. Once the burden has been entirely discharged to the satisfaction of the trier of fact, the party carrying the burden will succeed in its claim. For example, the presumption of innocence places a legal burden upon the prosecution to prove all elements of the offence (generally beyond a reasonable doubt) and to disprove all the defences except for affirmative defenses in which the proof of nonexistence of all affirmative defence(s) is not constitutionally required of the prosecution (432 U.S. 197).
- An "evidentiary burden" or "burden of leading evidence" is an obligation that shifts between parties over the course of the hearing or trial. A party may submit evidence that the court will consider prima facie proof of some state of affairs. This creates an evidentiary burden upon the opposing party to present evidence to refute the presumption.
- A "tactical burden" is an obligation similar to an evidentiary burden. Presented with certain evidence, the Court has the discretion to infer a fact from it unless the opposing party can present evidence to the contrary.
[edit] Standard of proof
The "standard of proof" is the level of proof required in a legal action to discharge the burden of proof, that is to convince the court that a given proposition is true. The degree of proof required depends on the circumstances of the proposition. Typically, most countries have two levels of proof or the balance of probabilities:
- preponderance of evidence - (lowest level of proof, used mainly in civil trials)
- beyond a reasonable doubt - (highest level of proof, used mainly in criminal trials)
In addition to these, the U.S. introduced a third standard called clear and convincing evidence, (which is the medium level of proof).
The first attempt to quantify reasonable doubt was made by Simon in 1970. In the attempt, she presented a trial to groups of students. Half of the students decided the guilt or innocence of the defendant. The other half recorded their perceived likelihood, given as a percentage, that the defendant committed the crime. She then matched the highest likelihoods of guilt with the guilty verdicts and the lowest likelihoods of guilt with the innocent verdicts. From this, she gauged that the cutoff for reasonable doubt fell somewhere between the highest likelihood of guilt matched to an innocent verdict and the lowest likelihood of guilt matched to a guilty verdict. From these samples, Simon concluded that the standard was between 0.70 and 0.74.[1]
[edit] Air of reality
The "air of reality" is a standard of proof used to determine whether a criminal defense may be used. The test asks whether a defense can be successful if it is assumed that all the claimed facts are to be true.
[edit] Reasonable suspicion
Reasonable suspicion is a low standard of proof in the U.S. to determine whether a brief investigative stop or a brief search by a police officer or any government agent is warranted. In Terry v. Ohio, , the United States Supreme Court ruled that reasonable suspicion requires specific, articulable, and individualized suspicion that crime is afoot. A mere guess or "hunch" is not enough to constitute reasonable suspicion. As a result of the low threshold, the extent of intrusiveness of the search and/or seizure allowed is lower than the extent of intrusiveness allowed when a government agent has probable cause to suspect that evidence of a crime will be found.
A good illustration of this is the continuum of a typical police/citizen interaction:
Consensual encounter between officer and citizen (no level of suspicion required) →a stop initiated by the officer that would cause a reasonable person to feel that he or she is not free to leave (reasonable suspicion required) →arrest (probable cause required).
[edit] Probable cause for arrest
Probable cause is a relatively low standard of evidence, which is used in the United States to determine whether a search, or an arrest, is warranted. It is also used by grand juries to determine whether to issue an indictment. In the civil context, this standard is often used where plaintiffs are seeking a prejudgment remedy.
In the criminal context, the U.S. Supreme Court in United States v. Sokolow, , determined that probable cause requires "a fair probability that contraband or evidence of a crime will be found" in determining whether Drug Enforcement Administration agents had a reason to execute a search. Courts vary when determining what constitutes a "fair probability," some say 30%, others 40%, others 51%.
[edit] Balance of probabilities
Balance of probabilities, also known as the preponderance of the evidence, is the standard required in most civil cases. The standard is met if the proposition is more likely to be true than not true. Effectively, the standard is satisfied if there is greater than 50 percent chance that the proposition is true. Lord Denning, in Miller v. Minister of Pensions,[2] described it simply as "more probable than not."
[edit] Clear and convincing evidence
Clear and convincing evidence is the higher level of burden of persuasion sometimes employed in the U.S. civil procedure. To prove something by "clear and convincing evidence", the party with the burden of proof must convince the trier of fact that it is substantially more likely than not that the thing is in fact true. This is a lesser requirement than "proof beyond a reasonable doubt", which requires that the trier of fact be close to certain of the truth of the matter asserted, but a stricter requirement than proof by "preponderance of the evidence," which merely requires that the matter asserted seem more likely true than not.
[edit] Beyond reasonable doubt
This is the standard required by the prosecution in most criminal cases within an adversarial system and is the highest level of burden of persuasion. This means that the proposition being presented by the government must be proven to the extent that there is no "reasonable doubt" in the mind of a reasonable person that the defendant is guilty. There can still be a doubt, but only to the extent that it would not affect a "reasonable person's" belief that the defendant is guilty. If the doubt that is raised does affect a "reasonable person's" belief that the defendant is guilty, the jury is not satisfied beyond a "reasonable doubt". The precise meaning of words such as "reasonable" and "doubt" are usually defined within jurisprudence of the applicable country.
[edit] Examples
[edit] Criminal law
In the West, criminal cases usually place the burden of proof on the prosecutor (expressed in the Latin brocard ei incumbit probatio qui dicit, non que negat, "the burden of proof rests on who asserts, not on who denies"). This principle is known as the presumption of innocence, but is not upheld in all legal systems or jurisdictions. Where it is upheld, the accused will be found not guilty if this burden of proof is not sufficiently shown by the prosecution.
For example, if the defendant (D) is charged with murder, the prosecutor (P) bears the burden of proof to show the jury that D did murder someone.
- Burden of proof: P
- Burden of production: P has to show some evidence that D had committed murder. The United States Supreme Court has ruled that the Constitution requires enough evidence to justify a rational trier of fact to find guilt beyond a reasonable doubt. If the judge rules that such burden has been met, then of course it is up to the jury itself to decide if they are, in fact, convinced of guilty beyond a reasonable doubt. See Jackson v. Virginia, 443 U.S. 307 (1979). If the judge finds there is not enough evidence under the standard, the case must be dismissed (or a subsequent guilty verdict must be vacated and the charges dismissed).
- e.g. witness, forensic evidence, autopsy report
- Failure to meet the burden: the issue will be decided as a matter of law (the judge makes the decision), in this case, D is presumed innocent
- Burden of persuasion: if at the close of evidence, the jury cannot decide if P has established with relevant level of certainty that D had committed murder, the jury must find D not guilty of the crime of murder
- Measure of proof: P has to prove every element of the offence beyond a reasonable doubt, but not necessarily prove every single fact beyond a reasonable doubt.
- Burden of production: P has to show some evidence that D had committed murder. The United States Supreme Court has ruled that the Constitution requires enough evidence to justify a rational trier of fact to find guilt beyond a reasonable doubt. If the judge rules that such burden has been met, then of course it is up to the jury itself to decide if they are, in fact, convinced of guilty beyond a reasonable doubt. See Jackson v. Virginia, 443 U.S. 307 (1979). If the judge finds there is not enough evidence under the standard, the case must be dismissed (or a subsequent guilty verdict must be vacated and the charges dismissed).
In other countries, criminal law reverses the burden of proof, and there is a presumption of guilt.
However, in England and Wales, the Magistrates' Courts Act 1980, s.101 stipulates that where a defendant relies on some "exception, exemption, proviso, excuse or qualification" in his defence, the legal burden of proof as to that exception falls on the defendant, though only on the balance of probabilities. For example, a person charged with being drunk in charge of a motor vehicle can raise the defence that there was no likelihood of his driving while drunk.[3] The prosecution have the legal burden of proof beyond reasonable doubt that the defendant exceeded the legal limit of alcohol and was in control of a motor vehicle. Possession of the keys is usually sufficient to prove control, even if the defendant is not in the vehicle and is perhaps in a nearby bar. That being proved, the defendant has the legal burden of proof on the balance of probabilities that he was not likely to drive.[4]
Similar rules exist in trial on indictment. Some defences impose an evidential burden on the defendant which, if met, imposes a legal burden on the prosecution. For example, if a person charged with murder pleads the right of self-defense, the defendant must satisfy the evidential burden that there are some facts suggesting self-defence. The legal burden will then fall on the prosecution to prove beyond reasonable doubt that the defendant was not acting in self-defence.[4]
In 2002, such practice in England and Wales was challenged as contrary to the European Convention on Human Rights (ECHR), art.6(2) guaranteeing right to a fair trial. The House of Lords held that such burdens were not contrary to the ECHR:[4][5]
- A mere evidential burden did not contravene art.6(2);
- A legal/ persuasive burden did not necessarily contravene art.6(2) so long as confined within reasonable limits, considering the questions:
- What must the prosecution prove to transfer burden to the defendant?
- Is the defendant required to prove something difficult or easily within his access?
- What is threat to society that the provision is designed to combat?
[edit] Civil law
In civil law cases, the "burden of proof" requires the plaintiff to convince the trier of fact (whether judge or jury) of the plaintiff's entitlement to the relief sought. This means that the plaintiff must prove each element of the claim, or cause of action, in order to recover.
The burden of proof must be distinguished from the "burden of going forward," which simply refers to the sequence of proof, as between the plaintiff and defendant. The two concepts are often confused.
[edit] Decisions by the U.S. Supreme Court
The Supreme Court discussed how courts should allocate the burden of proof (i.e., the burden of persuasion) in Schaffer ex rel. Schaffer v. Weast, 546 U.S. 49 (2005). The Supreme Court explained that if a statute is silent about the burden of persuasion, the court will "begin with the ordinary default rule that plaintiffs bear the risk of failing to prove their claims." In support of this proposition, the Court cited 2 J. Strong, McCormick on Evidence § 337, 412(5th ed. 1999), which states "The burdens of pleading and proof with regard to most facts have been and should be assigned to the plaintiff who generally seeks to change the present state of affairs and who therefore naturally should be expected to bear the risk of failure of proof or persuasion."
At the same time, the Supreme Court also recognized "The ordinary default rule, of course, admits of exceptions." "For example, the burden of persuasion as to certain elements of a plaintiff's claim may be shifted to defendants, when such elements can fairly be characterized as affirmative defenses or exemptions. See, e.g., FTC v. Morton Salt Co., 334 U.S. 37, 44-45 (1948). Under some circumstances this Court has even placed the burden of persuasion over an entire claim on the defendant. See Alaska Dept. of Environmental Conservation v. EPA, 540 U.S. 461, 494(2004)." Nonetheless, "[a]bsent some reason to believe that Congress intended otherwise, therefore, [the Supreme Court] will conclude that the burden of persuasion lies where it usually falls, upon the party seeking relief.
In Director, Office of Workers’ Compensation Programs v. Greenwich Collieries, 512 U.S. 267(1994), the Supreme Court explained that “burden of proof” is ambiguous because it has historically referred to two distinct burdens: the “burden of persuasion,” and the “burden of production."
In Keyes v. Sch. Dist. No. 1, 413 U.S. 189(1973), the Supreme Court stated: “There are no hard-and-fast standards governing the allocation of the burden of proof in every situation. The issue, rather, ‘is merely a question of policy and fairness based on experience in the different situations.'" For support, the Court cited 9 John H. Wigmore, Evidence § 2486, at 275 (3d ed. 1940)). In Keyes, the Supreme Court held that if “school authorities have been found to have practiced purposeful segregation in part of a school system,” the burden of persuassion shifts to the school to prove that it did not engaged in such discrimination in other segregated schools in the same system.
[edit] Science and other uses
Outside a legal context, "burden of proof" means that someone suggesting a new theory or stating a claim must provide evidence to support it: it is not sufficient to say "you can't disprove this." Specifically, when anyone is making a bold claim, it is not someone else's responsibility to disprove the claim, but is rather the responsibility of the person who is making the bold claim to prove it. In short, X is not proven simply because "not X" cannot be proven (see negative proof).
Taken more generally, the standard of proof demanded to establish any particular conclusion varies with the subject under discussion. Just as there is a difference between the standard required for a criminal conviction and in a civil case, so there are different standards of proof applied in many other areas of life.
The less reasonable a statement seems, the more proof it requires. The scientific consensus on cold fusion is a good example. The majority believes this can not really work, because believing that it would do so would force the alteration of a great many other tested and generally accepted theories about nuclear physics.
[edit] References
- ^ Distributions of Interest for Quantifying Reasonable Doubt and Their Applications. Retrieved on 2007-01-14.
- ^ Miller v. Minister of Pensions [1947] 2 All ER 372
- ^ Road Traffic Offenders Act 1988, s.5(2)
- ^ a b c Herring, J. (2004). Criminal Law: Text, Cases, and Materials. Oxford: Oxford University Press, 58-64. ISBN 0-19-876578-9.
- ^ R v. DPP, Ex Parte Kebeline [1999] UKHL 43
[edit] Bibliography
- Cooper, S. (2003). "Human Rights and Legal Burdens of Proof". Web Journal of Current Legal Issues 3.
[edit] External links
[edit] See also
- Probative or Probate
- Scientific method
- Occam's razor
- Burden of proof (logical fallacy)
- Statistical hypothesis testing
