9. Opinion evidence

This chapter, which focuses on opinion evidence in criminal and civil cases in the UK, explains the rule on the admissibility of opinion, including expert opinion, as well as notice and disclosure in criminal cases under the Criminal Procedure Rules 2014. The criteria for the admissibility of expert evidence, the responsibilities of expert witnesses, and the approach of the courts to new areas of expertise are examined in detail. It also considers the presentation of expert evidence, including the use of court-appointed experts, in civil cases under the Civil Procedure Rules, and, finally, examines the ultimate issue rule, which has been abolished by section 33(1) of the Civil Evidence Act 1972.