Evidence Law: Witnesses: 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 an expert. The judge may consider the witness's specialized (scientific, technical or other) opinion about evidence or about facts before the court within the expert's area of expertise, to be referred to as an "expert opinion". Expert witnesses may also deliver "expert evidence" within the area of their expertise. Their testimony may be rebutted by testimony from other experts or by other evidence or facts.

History.

The forensic expert practice is an ancient profession. For example, in ancient Babylonia, midwives were used as experts in determining pregnancy, virginity and female fertility. Similarly, the Roman Empire recognized midwives, handwriting experts and land surveyors as legal experts. The codified use of expert witnesses and the admissibility of their testimony and scientific evidence has developed significantly in the Western court system over the last 250 years. The concept of allowing an expert witness to testify in a court setting and provide opinionated evidence on the facts of other witnesses was first introduced by Lord Mansfield in the case of Folkes v Chadd in 1782. In this particular case, the court was hearing litigation regarding the silting of Wells Harbor in Norfolk and allowed leading civil engineer, John Smeaton, to provide scientific rationale behind the proposed legislation. The decision by the English Court to allow for an expert to provide contextual background and detail on a case is often cited as the root of modern rules on expert testimony.