An ultimate issue in criminal law is a legal issue at stake in the prosecution of a crime for which an expert witness is proviing testimony. For example, if the issue is the defendant's mental state at the time of the offense, the ultimate issue would be the defendant's sanity or insanity during the commission of the crime. In the past, expert witnesses were allowed to give testimony on ultimate issues, such as the applicability of the insanity defense to a particular defendant. However, after the 1982 trial of John Hinckley, Jr., the rules of evidence were changed. Now in the United States, federal and state rules of evidence specifically rule out legal conclusions drawn by expert witnesses in their testimony. However, a large amount of judicial discretion is allowed in how this rule is applied, resulting in an uneven application of rules across jurisdictions.