Examination of the Medical Expert
The expert witness differs essentially from the ordinary witness in at least two particulars; first, in that the field of his testimony is outside the range of ordinary knowledge and experience; and, secondly, in that his testimony in the great majority of cases is in the form of opinions or conclusions that are deemed necessary for the proper guidance of the jury. It goes without saying that the lawyer who undertakes the examination of the expert should have such familiarity with the subject of inquiry as will enable him to develop it through the expert logically and clearly, but unfortunately it does not go without saying that this is generally the case. Proper preparation for such an examination means not only a thorough study of the subject itself, but a careful planning with the expert as to the course of the examination, a complete understanding with him as to the theory to be developed, and in a case that calls for the use of the hypothetical question an exact agreement with him as to its content and form in each instance. But the matter of preparation for the examination of the expert is only incidental to this article, the primary object of which is the consideration of questions that have arisen upon the examination itself, particularly of the medical expert, and that have been adjudicated by courts of last resort.