The adversarial court system and the expert medical witness: 'The truth the whole truth and nothing but the truth?'.

Abstract

This discussion aims to provide the occasional medical expert witness with background knowledge of the adversarial court system and the role of the medical expert witness within it. The parallel evolution of the adversarial and inquisitorial legal systems has been more out of tradition rather than any systematic review of the effectiveness of one system or the other. Both legal systems have their merits and limitations. Witnesses within the adversarial system are required to present evidence in a structured and highly stylized format consisting of 'evidence in chief' followed by 'cross-examination'. This format is an attempt to exclude unreliable evidence. The medical witness is an 'expert' by means of specialized knowledge not possessed by the general public. This distinction allows the expert medical witness to offer his or her opinion as evidence. There remain several limitations to the expert's evidence and these relate to common knowledge, field of expertise and the 'ultimate issue'. The current practice of selection of expert medical witnesses is seriously flawed with several pressures operating to maximise bias and inaccurate testimony. Doctors should not only anticipate change in this area they should lead reform in this area.