Opinion ID: 1367790
Heading Depth: 1
Heading Rank: 4

Heading: an expert witness may be impeached with sworn testimony given in a prior unrelated case if the testimony is relevant and if it tends to explain, contradict or discredit the witness's testimony. here, the expert's prior inconsistent statements concerning river mechanics are admissible.

Text: Smicklas argues that prior inconsistent testimony in an unrelated case may be used to impeach an expert witness. Spitz does not disagree with the proposition. [25] Instead, he insists that the prior statements offered are irrelevant. We disagree. Both Smicklas and Spitz find support in this Court's pronouncement in Faulkenberry v. Kansas City S. Ry. Co., 661 P.2d 510, 514 (Okla. 1983), cert. denied, 464 U.S. 850, 104 S.Ct. 159, 78 L.Ed.2d 146 (1983). Smicklas cites Faulkenberry for the proposition that, generally, any matter is a proper subject of cross-examination if it is within the scope of direct examination; if it is relevant thereto; and if it tends to explain, contradict, or discredit a witness' testimony. Recognizing this premise, Spitz relies upon the Court's further statement that a witness may not be impeached by reference to some collateral or irrelevant matter. We agree with both parties concerning the general rule on impeachment espoused in Faulkenberry. However, Spitz's reliance on the case for the proposition that the inconsistent testimony offered for impeachment here is irrelevant is misplaced. Faulkenberry is distinguishable from the instant cause on its facts. There, we found that a psychological test conducted by another person and given before the source of the employee's physical problems had been diagnosed was irrelevant. Here, Spitz's expert witness testified that the use of heavy equipment on a sand base had nothing to do with the diversion of the river. Smicklas sought to impeach this testimony by the introduction of the same witnesses' prior inconsistent statement made in a deposition in another case involving the same river. [26] In the prior case, the expert testified that the use of heavy equipment on a sand base would compact it and make it more resistant to erosion. [27] In that case, the expert was asked whether such activity would have only a minimal impact on the river. He replied that the use of the equipment was the only thing which happened to cause the change in the course of the river. [28] In both the prior case and this one, use of heavy equipment on a sand base and its effect are relevant. Under these facts, the prior inconsistent statements of the expert witness were admissible for the purpose of impeachment. [29]