Medical expert testimony has received a severe blow from the way it has been used in certain prominent criminal trials of late years. It has been pronounced of no value at all, or even worse than that, by judges in the highest courts, and the public generally has come to place but little faith in the opinions of so-called medical experts. This is due to several causes lying behind the unfortunate exhibitions that have directly given rise to this discredit. The subject is well discussed in a recent paper by A. T. Clearwater,1 who, very justly attributes part of the evil to the bench and bar. His first reason seems really the principal one; that is the lack of any satisfactory standard of expertness, a condition which invites the testimony of charlatans and unscrupulous pretenders. The laxity of trial judges in admitting testimony and the freedom given to lawyers to make it difficult for a self-respecting person to endure their cross-examinations are also mentioned by him and are not matters to be disregarded.
THE HYPOTHETICAL QUESTION IN EXPERT TESTIMONY. JAMA. 2009;302(4):445. doi:10.1001/jama.2009.982