Opinion ID: 878969
Heading Depth: 1
Heading Rank: 1

Heading: did the district court commit error in excluding the testimony of dr. tranel regarding the causes of perceptual distortion encountered by patricia a. lindberg immediately before her death?

Text: This issue presents the question of the scope of expert testimony and the trial court's role in regulating it. Art. VII, M.R. Evid., deals with opinion and expert testimony. Rule 702, provides: If scientific, technical, or other specialized knowledge will assist the trier of fact to understand the evidence or to determine a fact in issue, a witness qualified as an expert by knowledge, skill, experience, training, or education may testify thereto in the form of an opinion or otherwise. (Emphasis added.) The facts of each case and the substance of the expert testimony offered must be considered on a case-by-case basis by the trial court to determine if the testimony falls within the rule. The proposed opinions offered by Dr. Tranel sought to establish that the perception of Mrs. Lindberg was so distorted because of the conditions created by defendants that a collison was very likely. The conditions caused the distortion and the distortion caused the accident. Dr. Tranel was going to supply the element of causation to appellants' case. Appellants rely heavily on State v. Chapple (1983), 135 Ariz. 281, 660 P.2d 1208, for the proposition that it is an abuse of discretion for the trial judge to exclude expert testimony that could possibly aid the jury in understanding a fact in issue. Appellants seek to broaden the law set forth in Chapple. The Arizona Supreme Court generally adhered to the criteria set forth in United States v. Amaral (9th cir. 1973), 488 F.2d 1148. Amaral and Chapple set forth factors we believe are useful in determining the admissibility of expert testimony. The Amaral factors are: (1) qualified expert; (2) proper subject; (3) conformity to generally accepted explanatory theory; and (4) probative value compared to prejudicial effect. The testimony offered in Chapple regarded the factors involved in assessing the reliability of the eyewitness testimony. No opinion was rendered regarding the ultimate credibility of specific witnesses. Chapple, 660 P.2d at 1222. Dr. Tranel was allowed to testify to factors involving perceptional distortion. He was not allowed to testify to how these factors affected Mrs. Lindberg's mental processes even as the expert in Chapple could not testify that the existence of an identification factor made a particular witnesses perception or memory faulty. Chapple was also limited to its facts on this issue. Chapple, 660 P.2d at 1224. We hold the trial court acted within its discretion in limiting the testimony of Dr. Tranel.