Opinion ID: 2072845
Heading Depth: 2
Heading Rank: 3

Heading: expert toxicology evidence

Text: Appellant's third contention is that the trial court abused its discretion in permitting the testimony of the Commonwealth's expert, a forensic toxicologist, with respect to appellant's blood alcohol content at the time of the accident. Specifically, appellant contends that the testimony of the Commonwealth's expert, Dr. G. Thomas Passananti, should not be considered where: (1) the Commonwealth failed to lay a proper foundation for the expert's opinion based on retrograde extrapolation; (2) the witness was permitted to testify regarding impairment at a blood alcohol content of less than .05%; and (3) the witness was permitted to contradict the judicially noticed fact that alcohol is absorbed into the bloodstream in the 30 to 90 minute period following its ingestion. We cannot agree. It is axiomatic that the admissibility of expert testimony is a matter within the broad discretion of the trial court and will not be disturbed on appeal absent a clear abuse of discretion. See Commonwealth v. Smallwood, 465 Pa. 392, 350 A.2d 822 (1976); Commonwealth v. Ametrane, 205 Pa.Super. 567, 210 A.2d 902, aff'd 422 Pa. 83, 221 A.2d 296 (1965). Under Pennsylvania law, an expert may not base an opinion on conjecture or guesswork, however, an expert opinion may be given in response to a hypothetical question posed by counsel so long as the assumed set of facts upon which the opinion is to be based is eventually supported by competent evidence and the reasonable inferences derivable therefrom. See Commonwealth v. Anderson, 381 Pa.Super. 1, 12-13, 552 A.2d 1064, 1070 (1988) citing Commonwealth v. Daniels, 480 Pa. 340, 390 A.2d 172 (1978). Moreover, any deficit in the clarity of, or basis for, the assumptions upon which the hypothetical is based, may be cured by adequate cross-examination, or redirect examination. Commonwealth v. Gilliard, 300 Pa. Super. 469, 446 A.2d 951 (1982). We have carefully reviewed the testimony of the Commonwealth's witness, Dr. Passananti, and find that his testimony regarding hypothetical questions and estimations fell within the permissible realm of expert testimony. Further, Dr. Passananti's answers were the type that would materially assist the jury in its search for truth on the issues. See Commonwealth v. Rodgers, 364 Pa.Super. 477, 528 A.2d 610 (1987); see also Commonwealth v. O'Searo, 466 Pa. 224, 352 A.2d 30 (1976). The expert was permitted to give an expert opinion based upon a hypothetical scenario presented by the Commonwealth which was plainly supported by reasonable inferences derivable from the evidence presented during the trial. Contrary to appellant's assertions, the scenario was supported by facts already presented, or expected and in fact later presented, regarding each of the variables the expert deemed relevant to this calculation of appellant's BAC at the time of the accident. Moreover, the expert was cross-examined in minute detail regarding the basis for his retrograde extrapolation of appellant's BAC at the time of the accident and in similar detail regarding the effects of any variance in the various relevant factors considered. We find that the foundation for the expert's retrograde extrapolation was sufficient, and any arguable defects in the foundation, because of the assumptions upon which it was based, were cured during the course of cross-examination. We note that the jury was specifically instructed that in accessing the weight to accord the expert testimony, it should consider, along with other factors, the degree to which the expert's hypothetical assumptions corresponded to their actual findings on the relevant facts. In Commonwealth v. Gonzalez, supra , our Supreme Court held that retrograde extrapolation testimony was improperly admitted when there was no evidence as to when the suspect had his last drink, because the expert opinion assumed a fact not supported by the evidence, i.e. that appellant's BAC peaked at or prior to the moment of impact. Our Supreme Court reasoned that the expert opinion should not have been admitted because it distorted the evidence presented, and permitted the jury to base its verdict on unsupported conjecture. 546 A.2d at 33-35. Here, on the other hand, the expert (giving appellant the benefit of all possible doubts) assumed for the purpose of the extrapolation that appellant drank his last beer at the moment of impact, and that since that alcohol would not have been absorbed into the blood stream, the BAC would have been .18 rather than .203, which the expert's calculation would otherwise have indicated. Moreover, with regard to appellant's assertion that there was no evidence as to when appellant consumed the alcohol detected by the blood test three and one half-hours after the accident, appellant himself and several other people at the party indicated that appellant had been drinking casually from about 8:30 p.m. to sometime around 2:45 a.m. that night. Neither appellant, nor Tony Kegg, nor any other witness indicated that appellant drank in the car, or had downed several beers shortly before leaving. Thus, the jury could reasonably infer from the evidence presented that appellant had one, two or at most three beers during the critical 30 to 90 minute period before the accident. Moreover, given the degree by which appellant's extrapolated BAC exceeded the legal limit, any variance between the expert's assumptions and the jury's actual findings with respect to how many beers appellant had within the critical 30 to 90 minute period before the accident would be inconsequential. [2] The jury was informed that the extrapolated BAC should be reduced from .203 by .02 for every beer consumed in the relevant time period. Hence, the jury was provided with a simple formula to reach its own estimate of the BAC, based upon its own findings rather than the expert's assumptions as to how many beers were consumed in that period. In this regard it is important to recall that appellant's precise BAC at the time of the accident was not critical to any issue at trial. Rather, the expert testimony was offered to assist the jury in determining whether the evidence established beyond a reasonable doubt that appellant's BAC was at least .10 at the time of the accident. Cf. Commonwealth v. Hanes, 361 Pa.Super. 357, 366-367, 522 A.2d 622, 626 (1987) (an accurate determination of the precise value of stolen logs was not required so long as the formula provided by the expert permitted jury to conclude beyond a reasonable doubt that the logs were worth at least a particular amount). Despite the imprecision involved, we find that the expert testimony was helpful, and not confusing or prejudicial under these circumstances. Hence, Gonzalez is materially distinguishable and therefore inapposite. Appellant's contention that the expert's references to the effects of alcohol at BAC levels less than .05 constitutes reversible error is likewise without merit. Here the evidence plainly established that appellant's BAC was above .10 at the time of the accident. Hence, the reference was superfluous, and harmless beyond a reasonable doubt in this case. Consequently, we decline to address appellant's novel contention that 75 Pa.C.S.A. § 1547(d) creates a conclusive negative presumption that persons with BAC levels of less than .05 are not intoxicated, and which mandates exclusion of evidence of the effects of BAC levels below .05 on an individual's driving skills. See generally Perrine, et al., Special Report 216: Zero Alcohol, Ch. 3 Alcohol, Performance, and Crash Risk, at 39-66 (Trans. Research Bd. 1987) (discussing the significant effects of BAC's at or below .04, collecting authorities). Finally, appellant's contention that the expert was improperly permitted to contradict a judicially noticed fact is also meritless. The fact judicially noticed, i.e. that alcohol is absorbed into the blood stream during a 30 to 90 minute period, is an expression of a convenient generality. The well-qualified expert in this case did not contradict that generalization. Rather, he merely elected to provide a more precise statement of the absorption phenomenon by explaining that absorption was unlike elimination in that absorption did not occur at a constant rate, and that the greater percentage of the alcohol consumed would be absorbed early in the period. He explained further that the 30 to 90 minute generalization reflected the time for total absorption. See Special Report 216: Zero Alcohol, supra, at 41-42 (discussing the absorption phenomenon in similar terms). We find no contradiction. More importantly, we find no basis in this record to question the well-qualified expert's explanation of the subtleties of the absorption process. Hence, each of appellant's challenges to the expert's testimony are found to be without merit.