Ultimate Issue (law) - Jeffrey R. MacDonald Trial

Jeffrey R. MacDonald Trial

An example of how this change in the rules of evidence can affect trial testimony is demonstrated in an analysis of the 1979 trial of Jeffrey R. MacDonald, a physician, for the murder of his wife and children, if his trial occurred today. In that trial, an expert testified in support of the defense hypothesis that someone else committed the murders. Expert testimony that the defendant had a "personality configuration inconsistent with the outrageous and senseless murders of family" was not allowed under the rules of evidence in effect at the time because it was considered confusing and misleading. However, under Rule 704(b) this character testimony would not be barred since testimony regarding "personality configuration" is general psychological evidence unrelated to any ultimate issues such as intent or malice aforethought. Also, an expert witness would not be in violation of 704(b) in use today if he gave testimony regarding the defendant's positive behaviors, such as acting like a loving father and husband, which might create the impression that he was not capable of committing such a crime, but is an opinion unrelated to guilt.