Although an expert generally may not give an opinion as to the credibility of a party or witness,44 such testimony may be admitted if it is used to illustrate the unreliability of a party’s statements when such statements are being offered as a basis for another expert’s opinion.45

The Delaware Supreme Court has had occasion to review the admissibility of expert testimony relating to the credibility of a victim of intra-family and intra-household child abuse. In each of those cases, the testimony was offered to bolster the credibility of the complaining witness against a member or members of his or her family or household. In the first case,46 the Supreme Court approved of the use of expert testimony in cases where the complaining child has behaved or made statements “superficially inconsistent with the occurrence of sexual abuse and which are established as especially attributable to intrafamily child sexual abuse rather than simply stress or trauma in general.”47 In approving such use, the Court recognized that such testimony in a given context might be unduly prejudicial as to the defendant’s credibility. For this reason the Court placed four conditions on its use: (i) notice must be given to all parties of intention to use such testimony sufficiently in advance of trial to allow preparation for cross-examination of the witness; (ii) voir dire as to the proffered testimony or qualification of the witness must be conducted out of the presence of the jury; (iii) the expert may not directly or indirectly express an opinion as to the veracity of any witness or attempt to quantify the truth or falsity of any statement; and (iv) the jury must be specifically instructed concerning the significance and limitation of the testimony.48 The conviction was reversed in that case  because the witness testified as to the statistical probability that the recantation statements of the child were false.

In the second of the intra-family child sexual abuse cases,49 the Supreme Court reversed a conviction because the expert validated the credibility of the complainant specifically and submitted quantifying percentage testimony, notwithstanding that it was elicited by counsel for the defendant during voir dire conducted in front of the jury. The Court reaffirmed the requirements it had delineated in the earlier case.

In the third of these cases,50 the Supreme Court sustained the conviction. The detective testified on direct examination of his interview with the child complainant but offered no opinion on the child’s credibility. On cross-examination, in response to questions by defense counsel as to whether he thought the child was credible, the detective stated that he considered her credible, and his answer was challenged on the basis that the child did not initially disclose all the facts, but only disclosed them gradually. The Supreme Court upheld the allowance of rebuttal testimony by the detective that it was more common than not that in such cases children disclose facts on a gradual basis. The Court stated that by virtue of the defendant’s cross-examination, he had opened the door to an explanation of why the detective found the child credible, notwithstanding the child’s failure to make full disclosure initially. The Court noted that it is within the knowledge of the average juror that a child who has not disclosed the whole truth of a story may in fact be fabricating part of the story. The Court went on to state that the psychological dynamics of a victim of child sexual abuse, including the tendency towards partial disclosure and recantation, are generally not within the knowledge of the average juror. Thus, it was appropriate for the trial judge to allow limited use of expert testimony to explain the disclosure tendencies of victims of child sexual abuse.51 The Court concluded that the testimony concerning gradual disclosure by victims of child sexual abuse concerned a characteristic of behavior that had been demonstrated by the child and which was material to the issue of the child’s credibility.52

The testimony on cross-examination could not have been submitted on direct because it was to the effect that the detective found the complainant to be credible. But the testimony on rebuttal was sustained because it was perfectly proper to “correct the false impression that the victim was likely to be lying” as well as the false impression concerning the professional judgment of the detective. Further, the testimony was proper because the detective did not rely on statistical probabilities of veracity, nor did he go beyond his own experience.53

In a later case, the Supreme Court held that expert testimony was not admissible under these precedents because the ten-year-old victim was not a family member.54

Expert testimony may be admissible to demonstrate why eyewitness testimony is unreliable in a given case, provided that the partty offering the expert demonstrates that such testimony is reliable55, and the expert testimony addresses and responds to the specific circumstances under which the eyewitness observed the event.56

44. Wheat v. State, 527 A.2d 269, 273 (Del. 1987); Powell v. State, 527 A.2d 276, 279 (Del. 1987); Re v. State, 54.0 A.2d 423, 427 (Del. 1988); Kleimann v. State, No. 297, 1986, slip op. at 2-3, Walsh, J. (Del. June 30, 1987) (ORDER), disposition reported at 528 A.2d 415 (Del. 1987) (TABLE). See also State v. Screpesi, 611 A.2d 34, 40 (Del. Super. 1991), aff’d mem., 609 A.2d 669 (Del. 1992) (opinion testimony as to a party’s character is inadmissible); Robin I. v. Dennis I., No. CN89-8500, slip op. at 3, Ableman, J. (Del. Fam. Nov. 21, 1990).

45. Re v. State, 540 A.2d 423, 427 (Del. 1988).

46. Wheat v. State, 527 A.2d 269 (Del. 1987).

47. Wheat v. State, 527 A.2d 269, 274 (Del. 1987).

48. Wheat v. State, 527 A.2d 269, 275-76 (Del. 1987).

49. Powell v. State, 527 A.2d 276 (Del. 1987).

50. Condon v. State, 597 A.2d 7 (Del. 1991), cert. denied, 511 U.S. 1008 (1994).

51. Condon v. State, 597 A.2d 7, 12 (Del. 1991), cert. denied, 511 U.S. 1008 (1994).

52. Condon v. State, 597 A.2d 7, 11 (Del. 1991), cert. denied, 511 U.S. 1008 (1994).

53. Condon v. State, 597 A.2d 7, 11-12 (Del. 1991), cert. denied, 511 U.S. 1008 (1994).

54. Floray v. State, 720 A.2d 1132, 1136 (Del. 1998).  See also State v. Redd, 642 A.2d 829, 832-33 (Del. Super. 1993).

55. See §18.3.

56. State v. Holmes, ID No. 11050100172, Johnston, J. (Del. Super. Sept. 19, 2012).

© 2012  David L. Finger