In law, a witness is someone who has knowledge about a matter, whether they have sensed it or are testifying on another witnesses' behalf. 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. In law a witness might be compelled to provide testimony in court, before a grand jury, before an administrative tribunal, before a deposition officer, or in a variety of other legal proceedings. A

subpoena A subpoena (; also subpœna, supenna or subpena) or witness summons is a writ issued by a government agency, most often a court, to compel testimony by a witness or production of evidence under a penalty for failure. There are two common types of ...

is a legal document that commands a person to appear at a proceeding. It is used to compel the

testimony In law and in religion, testimony is a solemn attestation as to the truth of a matter. Etymology The words "testimony" and "testify" both derive from the Latin word ''testis'', referring to the notion of a disinterested third-party witness. ...

of a witness in a

trial In law, a trial is a coming together of parties to a dispute, to present information (in the form of evidence) in a tribunal, a formal setting with the authority to adjudicate claims or disputes. One form of tribunal is a court. The tribunal ...

. Usually, it can be issued by a judge or by the lawyer representing the

plaintiff A plaintiff ( Π in legal shorthand) is the party who initiates a lawsuit (also known as an ''action'') before a court. By doing so, the plaintiff seeks a legal remedy. If this search is successful, the court will issue judgment in favor of t ...

or the defendant in a

civil trial In law, a trial is a coming together of parties to a dispute, to present information (in the form of evidence) in a tribunal, a formal setting with the authority to adjudicate claims or disputes. One form of tribunal is a court. The tribunal, ...

or by the prosecutor or the defense attorney in a criminal proceeding, or by a government agency. In many

jurisdiction Jurisdiction (from Latin 'law' + 'declaration') is the legal term for the legal authority granted to a legal entity to enact justice. In federations like the United States, areas of jurisdiction apply to local, state, and federal levels. J ...

s, it is compulsory to comply with the subpoena and either take an

oath Traditionally an oath (from Anglo-Saxon ', also called plight) is either a statement of fact or a promise taken by a sacrality as a sign of verity. A common legal substitute for those who conscientiously object to making sacred oaths is to g ...

or solemnly affirm to testify truthfully under penalty of

perjury Perjury (also known as foreswearing) is the intentional act of swearing a false oath or falsifying an affirmation to tell the truth, whether spoken or in writing, concerning matters material to an official proceeding."Perjury The act or an inst ...

. Although informally a witness includes whoever perceived the event, in law, a witness is different from an informant. A ''confidential informant'' is someone who claimed to have witnessed an event or have hearsay information, but whose identity is being withheld from at least one party (typically the criminal defendant). The information from the confidential informant may have been used by a police officer or other official acting as a hearsay witness to obtain a search warrant. = Types = A percipient witness (or eyewitness) is one with knowledge obtained through their own

sense A sense is a biological system used by an organism for sensation, the process of gathering information about the world through the detection of stimuli. (For example, in the human body, the brain which is part of the central nervous system re ...

s (e.g.,

visual perception Visual perception is the ability to interpret the surrounding Biophysical environment, environment through photopic vision (daytime vision), color vision, scotopic vision (night vision), and mesopic vision (twilight vision), using light in the ...

hearing Hearing, or auditory perception, is the ability to perceive sounds through an organ, such as an ear, by detecting vibrations as periodic changes in the pressure of a surrounding medium. The academic field concerned with hearing is audit ...

, smell, touch). That perception might be either with the unaided human sense or with the aid of an instrument, such as

microscope A microscope () is a laboratory instrument used to examine objects that are too small to be seen by the naked eye. Microscopy is the science of investigating small objects and structures using a microscope. Microscopic means being invisi ...

or stethoscope. A ''

hearsay Hearsay evidence, in a legal forum, is testimony from an under-oath witness who is reciting an out-of-court statement, the content of which is being offered to prove the truth of the matter asserted. In most courts, hearsay evidence is inadmiss ...

'' witness is one who testifies about what someone else said or wrote. In most court proceedings there are many limitations on when hearsay evidence is admissible. Such limitations do not apply to grand jury investigations, many administrative proceedings, and may not apply to declarations used in support of an arrest or search warrant. Also some types of statements are not deemed to be hearsay and are not subject to such limitations. An ''

expert witness An expert witness, particularly in common law countries such as the United Kingdom, Australia, and the United States, is a person whose opinion by virtue of education, training, certification, skills or experience, is accepted by the judge as ...

'' is one who allegedly has specialized knowledge relevant to the matter of interest, which knowledge purportedly helps to either make sense of other evidence, including other testimony, documentary evidence or physical evidence (e.g., a fingerprint). An expert witness may or may not also be a percipient witness, as in a doctor or may or may not have treated the victim of an accident or crime. A '' character witness'' testifies about the personality of a defendant if it helps to solve the crime in question. A ''

crown witness A criminal turns state's evidence by admitting guilt and testifying as a witness for the state against their associate(s) or accomplice(s), often in exchange for leniency in sentencing or immunity from prosecution.Howard Abadinsky, ''Organized ...

'' is one who incriminates former accomplices in a crime who following receive either a lower sentence, immunity or also a protection of themselves or/and their family by the court. After they have provided the court with their testimony they often enter into a witness protection program. A '' secret witness'' or ''anonymous witness'' is one whose identity is kept secret by the court.

Calling a witness

In a court proceeding, a witness may be ''called'' (requested to testify) by either the

prosecution A prosecutor is a legal representative of the prosecution in states with either the common law adversarial system or the Civil law (legal system), civil law inquisitorial system. The prosecution is the legal party responsible for presenting the ...

or the defense. The side that calls the witness first asks questions in what is called direct examination. The opposing side then may ask their own questions in what is called

cross-examination In law, cross-examination is the interrogation of a witness called by one's opponent. It is preceded by direct examination (in Ireland, the United Kingdom, Australia, Canada, South Africa, India and Pakistan known as examination-in-chief) and ...

. In some cases,

redirect examination Redirect examination, in the United States, is the questioning of a witness who has already provided testimony under oath in response to direct examination as well as cross examination by the opponent. On redirect, the attorney offering the wi ...

may be used by the side that called the witness but usually only to contradict specific testimony from the cross-examination. Recalling a witness means calling a witness, who has already given testimony in a proceeding, to give further testimony. A court may give leave to a party to recall a witness only to give evidence about a matter adduced by another party if the second party's testimony contradicts evidence given by the original witness on direct examination.

Testimony

Witnesses are usually permitted to testify only what they experienced first-hand. In most cases, they may not testify about something they were told (

). That restriction does not apply to expert witnesses, but they may testify only in the area of their expertise.

Reliability

Although eyewitness testimony is often assumed to be more reliable than circumstantial evidence, studies have established that individual, separate witness testimony is often flawed. Mistaken eyewitness identification may result from such factors as faulty observation and recollection, or bias, or may involve a witness's knowingly giving false testimony. If several people witness a crime, it is possible to look for commonalities in their testimony, which are more likely to represent events as they occurred, although differences are to be expected and don't of themselves indicate dishonesty. Witness identification will help investigators get an idea of what a criminal suspect looks like, but eyewitness recollection include mistaken or misleading elements. One study involved an experiment, in which subjects acted as

juror A jury is a sworn body of people (jurors) convened to hear evidence and render an impartial verdict (a finding of fact on a question) officially submitted to them by a court, or to set a penalty or judgment. Juries developed in England dur ...

s in a criminal case. Jurors heard a description of a robbery-murder, a prosecution argument, and then an argument for the defense. Some jurors heard only circumstantial evidence; others heard from a clerk who claimed to identify the defendant. In the former case, 18% percent found the defendant guilty, but in the latter case, 72% found the defendant guilty (Loftus 1988).

Police lineup A police lineup (in American English) or identity parade (in British English) is a process by which a crime victim or witness's putative identification of a suspect is confirmed to a level that can count as evidence at trial. The suspect, alo ...

s in which the eyewitness picks out a suspect from a group of people in the police station are often grossly suggestive, and they give the false impression that the witness remembered the suspect. In another study, students watched a staged crime. An hour later they looked through photos. A week later they were asked to pick the suspect out of lineups. 8% of the people in the lineups were mistakenly identified as criminals. 20% of the innocent people whose photographs were included were mistakenly identified. Weapon focus effects in which the presence of a weapon impairs

memory Memory is the faculty of the mind by which data or information is encoded, stored, and retrieved when needed. It is the retention of information over time for the purpose of influencing future action. If past events could not be remembered ...

for surrounding details is also an issue. Another study looked at 65 cases of "erroneous criminal convictions of innocent people." In 45% of the cases, eyewitness mistakes were responsible.Convicting the Innocent: Sixty-Five Actual Errors of Criminal Justice
by Borchard, pg 367 The formal study of eyewitness memory is usually undertaken within the broader category of

cognitive processes Cognition refers to "the mental action or process of acquiring knowledge and understanding through thought, experience, and the senses". It encompasses all aspects of intellectual functions and processes such as: perception, attention, thought, ...

, the different ways in which we make sense of the world around us. That is done by employing the mental skills at one's disposal like thinking, perception, memory, awareness, reasoning, and judgment. Although cognitive processes can be only inferred and cannot be seen directly, they all have very important practical implications within a legal context. If one were to accept that the way people think, perceive, reason, and judge is not always perfect, it becomes easier to understand why cognitive processes and the factors influencing the processes are studied by psychologists in matters of law, one being the grave implications that this imperfection can have within the criminal justice system. The study of witness memory has dominated the realm of investigation. As Huff and Rattner note, the single most important factor contributing to wrongful conviction is eyewitness misidentification.

Credibility

A credible witness is a person who acts as a witness, including through giving

court A court is any person or institution, often as a government institution, with the authority to adjudicate legal disputes between parties and carry out the administration of justice in civil, criminal, and administrative matters in acco ...

, whose testimony is perceived as truthful and believable. Other witnesses may be perceived as less credible, or to have no credibility. Assessment of credibility is made of each witness, and is not affected by the number of witnesses who testify. Several factors affect witnesses' credibility. Generally, witnesses are perceived as more credible when they are perceived as more accurate and less suggestible. At

common law In law, common law (also known as judicial precedent, judge-made law, or case law) is the body of law created by judges and similar quasi-judicial tribunals by virtue of being stated in written opinions."The common law is not a brooding omnipres ...

, the term could be used in relation to the giving of testimony, or for the witnessing of documents. In modern English law, a credible witness is one who is ''not'' "speaking from

." In

Scottish law Scots law () is the legal system of Scotland. It is a hybrid or mixed legal system containing civil law and common law elements, that traces its roots to a number of different historical sources. Together with English law and Northern Ireland ...

, a credible witness is one "whose credibility commends itself to the presiding magistrate ... the trustworthiness" of whom is good.

Witnessing of wills and documents

Credible witnesses must be used to give meaning or existence to certain types of legal documents. For example, in most

common law jurisdiction In law, common law (also known as judicial precedent, judge-made law, or case law) is the body of law created by judges and similar quasi-judicial tribunals by virtue of being stated in written opinions."The common law is not a brooding omniprese ...

s, at least two witnesses must sign their names to a will in order to verify that it was executed by the testator. In

Canadian law The legal system of Canada is pluralist: its foundations lie in the English common law system (inherited from its period as a colony of the British Empire), the French civil law system (inherited from its French Empire past), and Indigenous ...

, a credible witness to a Will means a witness who is not incapacitated by mental deficiency, conflict of interest, or crime.

References

External links

Eyewitness memory
{{Authority control Evidence law