ABSTRACT
This chapter examines the role of the expert and discusses legal principles relating to the expert witness in a number of jurisdictions. In general, evidence that does not relate to matters within the immediate experience of the witness is inadmissible in common law. In a lecture to the Middle Temple, Lord Hodge stated that the expert witness has both privilege and power – privilege to give their opinion and power because of their knowledge and the difficulties a lawyer has in cross-examination of a well-prepared expert. The need for objectivity applies with perhaps greater force to evidence of medical expertise than to any other area of knowledge. Medical expert opinion is often readily accepted by the tribunal of fact, in particular by juries, precisely because of the respectable and respected body of opinion from which it derives. A number of cases, both civil and criminal, have laid down the duties of an expert.
