Definition

Noun: A person who is permitted to testify at a trial because of special knowledge or proficiency in a particular field that is relevant to the case. This knowledge is beyond that of the average person.

Usage

An expert witness provides an opinion based on their expertise to help the judge or jury understand complex evidence or to determine a fact in issue. - The role is formal and occurs within a legal proceeding. - The expert's testimony is subject to cross-examination by the opposing side. - The expert must be qualified and accepted as such by the court.

Examples

• Noun:
  • The defense called an expert witness in forensic psychology to testify about the defendant's state of mind.
  • The judge must decide if the proposed expert witness is qualified to give an opinion on the engineering failure.

Advanced Usage

• "To qualify as an expert witness": The process by which a court accepts a person's specialized knowledge as sufficient to provide expert testimony.
  • The attorney asked a series of questions to qualify the doctor as an expert witness.
• "Expert witness testimony": The opinion or evidence given by the expert while on the witness stand.
  • The jury found the expert witness testimony on DNA analysis to be very compelling.

Variants and Related Words

• Expert testimony (n): The evidence or opinion provided by an expert witness. This is a related term for the content of the witness's statement.
  • The case hinged on the expert testimony regarding the software's security flaws.
• Lay witness (n): A witness who testifies about facts they personally observed, not offering specialized opinions. This is a contrasting term.
  • Unlike an expert witness, a lay witness cannot give an opinion on the cause of the accident.

Synonyms

• Specialist witness: A witness with specialized knowledge. (Less common)
• Technical witness: Emphasizes expertise in a technical field.

Related Phrases

• "To be called as an expert witness": To be formally requested to provide expert testimony in a case.
  • She was called as an expert witness in several high-profile patent lawsuits.
• "Daubert standard": A rule of evidence regarding the admissibility of expert witness testimony in United States federal courts, requiring the testimony to be based on reliable methodology.
  • The expert's report was challenged under the Daubert standard.

Noun

1. a witness who has knowledge not normally possessed by the average person concerning the topic that he is to testify about