In law, a witness is someone who, either voluntarily or under compulsion, provides testimonial evidence, either oral or written, of what they know or claim to know.
Testimony is a solemn attestation as to the truth of a matter.
Hearsay is testimony from a witness under oath who is reciting an out-of-court statement that is being offered to prove the truth of the matter asserted.
The parol evidence rule is a rule in common law jurisdictions limiting the kinds of evidence parties to a contract dispute can introduce when trying to determine the specific terms of a contract and precluding parties who have reduced their agreement to a final written document from later introducing other evidence, such as the content of oral discussions from earlier in the negotiation process, as evidence of a different intent as to the terms of the contract. The rule provides that "extrinsic evidence is inadmissible to vary a written contract". The term "parol" derives from the Anglo-Norman French parol or parole, meaning "word of mouth" or "verbal", and in medieval times referred to oral pleadings in a court case.
In United States federal law, the Daubert standard is a rule of evidence regarding the admissibility of expert witness testimony. A party may raise a Daubert motion, a special motion in limine raised before or during trial, to exclude the presentation of unqualified evidence to the jury. The Daubert trilogy are the three United States Supreme Court cases that articulated the Daubert standard:
Daubert v. Merrell Dow Pharmaceuticals, Inc., 509 U.S. 579 (1993), is a United States Supreme Court case determining the standard for admitting expert testimony in federal courts. In Daubert, the Court held that the enactment of the Federal Rules of Evidence implicitly overturned the Frye standard; the standard that the Court articulated is referred to as the Daubert standard.
First adopted in 1975, the Federal Rules of Evidence codify the evidence law that applies in United States federal courts. In addition, many states in the United States have either adopted the Federal Rules of Evidence, with or without local variations, or have revised their own evidence rules or codes to at least partially follow the federal rules.
Character evidence is a term used in the law of evidence to describe any testimony or document submitted for the purpose of proving that a person acted in a particular way on a particular occasion based on the character or disposition of that person. In the United States, Federal Rule of Evidence 404 maps out its permissible and prohibited uses in trials. Three factors typically determine the admissibility of character evidence:
- the purpose for which the character evidence is being used
- the form in which the character evidence is offered
- the type of proceeding in which the character evidence is offered
The best evidence rule is a legal principle that holds an original of a document as superior evidence. The rule specifies that secondary evidence, such as a copy or facsimile, will be not admissible if an original document exists and can be obtained. The rule has its roots in 18th-century British law, at a time when copies would be rewritten by hand and hence more vulnerable to inaccuracies.
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. 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.
A learned treatise, in the law of evidence, is a text that is sufficiently authoritative in its field to be admissible as evidence in a court in support of the contentions made therein.
Admissible evidence, in a court of law, is any testimonial, documentary, or tangible evidence that may be introduced to a factfinder—usually a judge or jury—to establish or to bolster a point put forth by a party to the proceeding. For evidence to be admissible, it must be relevant and "not excluded by the rules of evidence", which generally means that it must not be unfairly prejudicial, and it must have some indicia of reliability. The general rule in evidence is that all relevant evidence is admissible and all irrelevant evidence is inadmissible, though some countries proscribe the prosecution from exploiting evidence obtained in violation of constitutional law, thereby rendering relevant evidence inadmissible. This rule of evidence is called the exclusionary rule. In the United States, this was effectuated federally in 1914 under the Supreme Court case Weeks v. United States and incorporated against the states in 1961 in the case Mapp v. Ohio. Both of these cases involved law enforcement conducting warrantless searches of the petitioners' homes, with incriminating evidence being described inside them.
Witness impeachment, in the law of evidence of the United States, is the process of calling into question the credibility of an individual testifying in a trial. The Federal Rules of Evidence contain the rules governing impeachment in US federal courts.
The Indian Evidence Act, originally passed in India by the Imperial Legislative Council in 1872, during the British Raj, contains a set of rules and allied issues governing admissibility of evidence in the Indian courts of law.
The Testimony of the Evangelists, Examined by the Rules of Evidence Administered in Courts of Justice is an 1846 Christian apologetic work by Simon Greenleaf (1783-1853), an early professor (1833-1848) of the Harvard Law School.
Hearsay, in a legal forum, is an out-of-court statement which is being offered in court for the truth of what was asserted. In most courts, hearsay evidence is inadmissible unless an exception to the hearsay rule applies.
The hearsay provisions of the Criminal Justice Act 2003 reformed the common law relating to the admissibility of hearsay evidence in criminal proceedings begun on or after 4 April 2005.
In the law of the United States of America, an objection is a formal protest raised in court during a trial to disallow a witness's testimony or other evidence in violation of the rules of evidence or other procedural law. An objection is typically raised after the opposing party asks a question of the witness, but before the witness can answer, or when the opposing party is about to enter something into evidence. The judge then makes a ruling on whether the objection is "sustained" or "overruled". An attorney may choose to "rephrase" a question that has been objected to, so long as the judge permits it. Lawyers should make an objection before there is an answer to the question. Research finds that frequent objections by attorneys do not alienate jurors.
Relevance, in the common law of evidence, is the tendency of a given item of evidence to prove or disprove one of the legal elements of the case, or to have probative value to make one of the elements of the case likelier or not. Probative is a term used in law to signify "tending to prove". Probative evidence "seeks the truth". Generally in law, evidence that is not probative is inadmissible and the rules of evidence permit it to be excluded from a proceeding or stricken from the record "if objected to by opposing counsel". A balancing test may come into the picture if the value of the evidence needs to be weighed versus its prejudicial nature.
The Scientific Working Group on Imaging Technology was convened by the Federal Bureau of Investigation in 1997 to provide guidance to law enforcement agencies and others in the criminal justice system regarding the best practices for photography, videography, and video and image analysis. This group was terminated in 2015.
