What is an expert Witness?

An expert witness is a witness who by virtue of education, training, skill, or experience, is believed to have knowledge of a particular subject beyond that of the average person, insofar that others may officially (and legally) rely upon the witness’s specialized (scientific, technical, or other) knowledge about evidence or fact issues within their field of expertise: Referred to as an expert opinion. Expert witnesses may also present expert evidence about facts based on their expertise. At times, their testimony may be rebutted with a learned treatise, sometimes to the detriment of their reputations.

Typically, experts are relied upon for opinions regarding severity of injury, degree of insanity, cause of failure in a machine or other device, loss of earnings, care costs etc. In an intellectual-property case, an expert may be shown two music scores, book texts, or circuit boards and be asked to ascertain their degree of similarity.

The tribunal itself, or the judge, can in some systems call upon experts to technically evaluate a certain fact or action, in order to provide the court with an in-depth knowledge of the fact/action it is judging. The expertise has the legal value of an acquisition of data. The results of these experts’ input are then compared to those of the experts of all the parties involved in the case.

The expert has a heavy responsibility, especially in penal trials. Perjury by an expert witness is a severely punished crime in most countries.

The Role of an Expert Witness & The Benefits of Using One:

The role of expert witnesses is to bring clarity to the court. In cases covering complex subjects, it is often advisable to retain an expert witness. The expert has a number of roles. First, he or she consults with the attorney regarding the merits of the case. Second, the expert is charged with reviewing all the evidence and authoritative subjects on the matter. Third, the expert is charged with rendering an opinion regarding the subject. Fourth, the expert witness has the task of explaining a complex subject in such a way that the court can readily understand it.

The expert has a heavy responsibility, especially in penal trials, and perjury by an expert is a severely punished crime in most countries.