Evidence (law)
The law of evidence, also known as the rules of evidence, encompasses the rules and legal principles that govern the proof of facts in a legal proceeding. These rules determine what evidence must or must not be considered by the trier of fact in reaching its decision. The trier of fact is a judge in bench trials, or the jury in any cases involving a jury.[1] The law of evidence is also concerned with the quantum (amount), quality, and type of proof needed to prevail in litigation. The rules vary depending upon whether the venue is a criminal court, civil court, or family court, and they vary by jurisdiction.
For other uses, see Evidence (disambiguation).
The quantum of evidence is the amount of evidence needed; the quality of proof is how reliable such evidence should be considered. Important rules that govern admissibility concern hearsay, authentication, relevance, privilege, witnesses, opinions, expert testimony, identification and rules of physical evidence. There are various standards of evidence, standards showing how strong the evidence must be to meet the legal burden of proof in a given situation, ranging from reasonable suspicion to preponderance of the evidence, clear and convincing evidence, or beyond a reasonable doubt.
There are several types of evidence, depending on the form or source. Evidence governs the use of testimony (e.g., oral or written statements, such as an affidavit), exhibits (e.g., physical objects), documentary material, or demonstrative evidence, which are admissible (i.e., allowed to be considered by the trier of fact, such as jury) in a judicial or administrative proceeding (e.g., a court of law).
When a dispute, whether relating to a civil or criminal matter, reaches the court there will always be a number of issues which one party will have to prove in order to persuade the court to find in their favour. The law must ensure certain guidelines are set out in order to ensure that evidence presented to the court can be regarded as trustworthy.
History[edit]
Ancient and medieval law[edit]
The Old Testament demanded at least two witnesses for conviction of a crime.[2][3]
Ancient Roman law allowed freedom to judges to evaluate evidence, but insisted that "proof is incumbent on the party who affirms a fact, not on him who denies it" and "no-one should be convicted on suspicion".[4] Medieval Roman law developed an elaborate grading of degrees of evidence. Building on the Biblical two-witness rule, it concluded that a single witness, or private documents, could constitute half-proof, which though insufficient for conviction might justify torture to extract further evidence.[4]: 26–7, 59 Because evidence in the continental (civil law) system was evaluated by judges rather than juries, that system did not develop exclusionary rules of evidence in the way English law did.
Anglophone (Common) law[edit]
A distinct feature of English common law historically was the role of the jury as a finder of fact, as opposed to the role of the judge as finder of law.[5] The creation of modern jury trials in the 16th and 17th centuries necessitated rules of evidence to regulate what testimony and other evidence could be put before the jury.[6] While much of the early common law evidence rules came from judicial decisions, the English Parliament also played a role. In 1677, Parliament and the Crown enacted the Statute of Frauds and Perjuries, prohibiting plaintiffs from alleging certain contractual breaches to the jury unless accompanied by a signed, written instrument. Another early evidence rule was the prohibition on hearsay, the admission of an out-of-court statement to prove the truth of what is asserted. In the early 19th Century, Chief Justice Lord Mansfield of the Court of Common Pleas stated:
Hearsay rules have subsequently been updated numerous times. Most recently in England and Wales, the Civil Evidence Act 1995, section 1, specifically allows for admission of 'hearsay' evidence; legislation also allows for 'hearsay' evidence to be used in criminal proceedings, which makes it possible for the accuser to induce friends or family to give false evidence in support of their accusations because, normally, it would be rejected by the presiding authority or judge. There are several examples where presiding authorities are not bound by the rules of evidence. These include the military tribunals in the United States and tribunals used in Australia to try health professionals.
Presence or absence of a jury[edit]
The United States has a very complicated system of evidentiary rules; for example, John Wigmore's celebrated treatise on it filled ten volumes.[10] James Bradley Thayer reported in 1898 that even English lawyers were surprised by the complexity of American evidence law, such as its reliance on exceptions to preserve evidentiary objections for appeal.[10]
Some legal experts, notably Stanford legal historian Lawrence Friedman, have argued that the complexity of American evidence law arises from two factors: (1) the right of American defendants to have findings of fact made by a jury in practically all criminal cases as well as many civil cases; and (2) the widespread consensus that tight limitations on the admissibility of evidence are necessary to prevent a jury of untrained laypersons from being swayed by irrelevant distractions.[10] In Professor Friedman's words: "A trained judge would not need all these rules; and indeed, the law of evidence in systems that lack a jury is short, sweet, and clear."[11] However, Friedman's views are characteristic of an earlier generation of legal scholars. The majority of people now reject the formerly-popular proposition that the institution of trial by jury is the main reason for the existence of rules of evidence even in countries such as the United States and Australia; they argue that other variables are at work.[12]
Authentication[edit]
Certain kinds of evidence, such as documentary evidence, are subject to the requirement that the offeror provide the trial judge with a certain amount of evidence (which need not be much and it need not be very strong) suggesting that the offered item of tangible evidence (e.g., a document, a gun) is what the offeror claims it is. This authentication requirement has import primarily in jury trials. If evidence of authenticity is lacking in a bench trial, the trial judge will simply dismiss the evidence as unpersuasive or irrelevant. Other kinds of evidence can be self-authenticating and require nothing to prove that the item is tangible evidence. Examples of self-authenticating evidence includes signed and certified public documents, newspapers, and acknowledged documents.[14]
Direct vs. circumstantial evidence[edit]
Direct evidence is any evidence that directly proves or disproves a fact. The most well-known type of direct evidence is a testimony from an eyewitness. In eye-witness testimonies the witness states exactly what they experienced, saw, or heard. Direct evidence may also be found in the form of documents. In cases that involve a breach of contract, the contract itself would be considered direct evidence as it can directly prove or disprove that there was breach of contract. Circumstantial evidence, however, is evidence that does not point directly to a fact and requires an inference in order to prove that fact.
A common example of the distinction between direct and circumstantial evidence involves a person who comes into a building, when it may be raining. If the person declares, "It's raining outside", that statement is direct evidence that it is raining. If the person is carrying a wet umbrella, and he is wearing a wet rain coat, those observations are circumstantial evidence that it is raining outside.[17]
Evidentiary rules stemming from other areas of law[edit]
Some rules that affect the admissibility of evidence are nonetheless considered to belong to other areas of law. These include the exclusionary rule of criminal procedure, which prohibits the admission in a criminal trial of evidence gained by unconstitutional means, and the parol evidence rule of contract law, which prohibits the admission of extrinsic evidence of the contents of a written contract.
Evidence as an area of study[edit]
In countries that follow the civil law system, evidence is normally studied as a branch of procedural law.
All American law schools offer a course in evidence, and most require the subject either as a first year class, or as an upper-level class, or as a prerequisite to later courses. Furthermore, evidence is heavily tested on the Multistate Bar Examination (MBE) - approximately one-sixth of the questions asked in that test will be in the area of evidence. The MBE predominantly tests evidence under the Federal Rules of Evidence, giving little attention to matters on which the law of different states is likely to be inconsistent.
