A witness with a specialized knowledge of a subject who is allowed to discuss an event in court even though he or she was not present. For example, an arson expert could testify about the probable cause of a suspicious fire.
witness who, by reason of education or experience, possesses superior knowledge in a subject and is qualified by the court and, therefore, permitted to assist the jury in understanding complicated and technical subject matter not within the understanding of the average lay person.
A type of person testifying in a legal proceeding in an agency or court who, because of special education and experience is allowed to testify based on hearsay, assumptions, and hypothetical questions. As opposed to a lay witness who is allowed to testify only on the basis of facts.