Opinion ID: 2087006
Heading Depth: 1
Heading Rank: 4

Heading: The Evidence of Malingering and Anti-Social Personality.

Text: Re objects to Dr. Dietz's testimony that Re was malingering and that he had an anti-social personality disorder. Re argues that this testimony was prejudicial and should have been excluded because it was irrelevant and/or because it was evidence of Re's credibility. Evidence is relevant if it tends to make more or less probable a fact important to the outcome of a case. D.R.E. 401. The decision as to relevance is vested in the discretion of the trial judge. Lampkins v. State, Del.Supr., 465 A.2d 785, 790 (1983). When an expert relies upon the oral representations of another person to reach his conclusion, the jury must determine the credibility of both the expert and the person upon whom he relied. Debernard v. Reed, Del.Supr., 277 A.2d 684, 685 (1971). Thus, evidence bearing upon the truthfulness of the third party's representations clearly is relevant. Re's defense heavily relied upon the expert testimony by Drs. Galliani and Weintraub that he was suffering from extreme emotional distress at the time of the murder of Jayne Griffin. Such testimony was based almost exclusively on the experts' conversations with Re after the incident. The State then presented Dr. Dietz to show that Re was feigning mental illness. The logical result of Dr. Dietz's conclusion is that anything Re said during the interviews with Drs. Galliani and Weintraub was not credible. The testimony of Dr. Dietz tended to make less probable the truthfulness of Re's statements to his expert witnesses. Under the circumstances, it clearly was relevant. Although an expert may not, generally, testify regarding the credibility of a defendant, Wheat v. State, Del.Supr., 527 A.2d 269, 274-75 (1987); Powell v. State, Del.Supr., 527 A.2d 276, 279-80 (1987), the court may allow such testimony if it is used to illustrate the unreliability of the defendant's statements when they are being offered as a basis for an expert opinion. When an expert relies on the statements of another person in formulating an opinion, that person's credibility is at issue. Debernard v. Reed, Del.Supr., 277 A.2d 684, 685 (1971). See Fensterer v. State, Del.Supr., 509 A.2d 1106, 1109 (1986) (establishing basis for expert opinion is prerequisite to admission). [6] In judging the credibility of the speaker, the jury should have the benefit of any information which might illuminate the speaker's propensity for truthfulness or the lack of it. Although the issue of credibility of an expert witness, or of a person who makes statements upon which that expert relies, is ultimately for the jury, an adverse party should not be precluded from impeaching either the testimony of the expert or the foundation of that testimony.