161 F.3d 77 (1st Cir. 1998), 98-1163, Ruiz-Troche v. Pepsi Cola of Puerto Rico Bottling Co.

Docket Nº:98-1163.
Citation:161 F.3d 77
Party Name:Julio Elvin RUIZ-TROCHE, et al., Plaintiffs, Appellees, v. PEPSI COLA OF PUERTO RICO BOTTLING COMPANY, et al., Defendants, Appellants.
Case Date:December 01, 1998
Court:United States Courts of Appeals, Court of Appeals for the First Circuit

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161 F.3d 77 (1st Cir. 1998)

Julio Elvin RUIZ-TROCHE, et al., Plaintiffs, Appellees,



Defendants, Appellants.

No. 98-1163.

United States Court of Appeals, First Circuit

December 1, 1998

Heard Sept. 15, 1998.

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[Copyrighted Material Omitted]

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Stephen A. Cozen with whom Elizabeth J. Chambers, Cozen and O'Connor, Francisco J. Col¢n-Pagan, Francisco E. Col¢n-Ram¡rez, and Col¢n, Col¢n & Martinez were on brief, for appellants.

Jose F. Quetglas Jordan and Jorge Carazo-Quetglas, with whom Eric M. Quetglas Jordan, Quetglas Law Offices, and Toledo Toledo & Carazo-Quetglas, P.C. were on brief, for appellees.

Before SELYA, Circuit Judge, ALDRICH, Senior Circuit Judge, and BOUDIN, Circuit Judge.

SELYA, Circuit Judge.

This appeal requires us to explore the limits of a trial court's authority to exclude scientific evidence--in this instance, evidence of alleged cocaine use by the driver of a motor vehicle involved in a fatal accident and evidence of his ensuing impairment--under Daubert v. Merrell Dow Pharm., Inc., 509 U.S. 579, 113 S.Ct. 2786, 125 L.Ed.2d 469 (1993). We conclude that the court below abused its discretion in excluding certain of this evidence and that the magnitude of the error necessitates a new trial.


On an afternoon in September of 1992, Julio Elvin Ruiz Cintr¢n (Ruiz) was driving a Toyota automobile westerly along a two-lane road in Puerto Rico. At what proved to be the critical moment, Ruiz left his lane to pass a slow-moving vehicle. Seconds later, his car collided with an oncoming eastbound tractor-trailer rig. Ruiz, his wife, son, and three other passengers (all minors) were killed. Ruiz's four-year-old daughter survived, but sustained permanent brain damage.

In due course, Ruiz's daughter, joined by other relatives of the various decedents (all of whom, at the time of suit, were citizens of mainland states), invoked diversity jurisdiction, 28 U.S.C. § 1332(a), and brought suit for damages in Puerto Rico's federal district court. They named as defendants the driver of the tractor-trailer unit, Juan Hernandez Rosario (Hernandez); his employer, Los Vaqueros de Transporte y Carga; the consignor, Pepsi Cola of Puerto Rico Bottling Company; and several insurers. The plaintiffs averred (1) that Hernandez needlessly accelerated his rig as the Toyota approached, thereby shortening the available time within which Ruiz could complete his passing maneuver and return to his own side of the road, and (2) that Hernandez refused to veer to the right to avoid the accident, despite having sufficient space and time to do so. The defendants denied the essential allegations of the complaint. They argued that Ruiz, and Ruiz alone, had caused the accident by recklessly initiating a passing maneuver in the face of obvious danger and placing his vehicle on the wrong side of the road. To bolster this thesis, the defendants sought to show that cocaine intoxication provoked Ruiz's recklessness.

The district court stymied the defendants' anticipated trial strategy by refusing to admit into evidence either the toxicology section of the autopsy report (which reflected the presence of cocaine and cocaine metabolites in Ruiz's bloodstream) or expert testimony regarding the significance of these findings. In the court's view, the proposed expert testimony failed to meet the standard of reliability required under Daubert. Having rejected the expert testimony, the court then excluded the toxicology results under Fed.R.Evid. 403, concluding that those results, standing alone and unexplained, were more prejudicial than probative.

In diversity cases, local law provides the substantive rules of decision. See Erie R.R. Co. v. Tompkins, 304 U.S. 64, 78, 58 S.Ct. 817, 82 L.Ed. 1188 (1938); Daigle v. Maine Med. Ctr., Inc., 14 F.3d 684, 689 (1st Cir.1994). Puerto Rico law recognizes comparative negligence principles. See P.R. Laws Ann. tit. 31, § 5141 (1990). The trial judge instructed accordingly, and the jury found both drivers negligent, assigning 59% of the fault to Ruiz and 41% to Hernandez.

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It then awarded damages totaling approximately $13,000,000 to the various plaintiffs. Due to Puerto Rico's combination of comparative negligence and joint and several liability rules, the defendants will be required to pay the full amount of these damages if the judgment becomes final. 1

In the aftermath of the jury verdict, the defendants moved for judgment as a matter of law, Fed.R.Civ.P. 50, or, alternatively, for a new trial, Fed.R.Civ.P. 59. The district court rejected the defendants' plaints, including those that centered on the allegedly wrongful exclusion of the expert testimony and toxicology results. This appeal ensued.


The Daubert questions in this case are complex and implicate four interrelated pieces of evidence: (1) the toxicology results contained in the autopsy report; (2) the so-called "dosage" testimony, i.e., the expert opinions of a pharmacologist relating to the amount of drugs that Ruiz consumed and the time of their consumption, arrived at by interpolation from the toxicology results; (3) the so-called "impairment" testimony, i.e., the pharmacologist's expert opinions regarding the effects of cocaine on behavior; and (4) the so-called "causation" testimony, i.e., certain expert opinions of the defense's accident reconstructionist. After surveying the legal landscape, we discuss how these items came before the district court and how the court handled them. We then explicate the standard of review and proceed to test the correctness of the district court's rulings.

  1. Daubert Revisited.

    The Evidence Rules generally confine the testimony of a lay witness to matters about which he or she has personal knowledge, see Fed.R.Evid. 602, although such a witness may offer opinions that are "rationally based on [his or her] perception" and "helpful to a clear understanding of the witness' testimony or the determination of a fact in issue," Fed.R.Evid. 701. The Rules afford expert witnesses much more leeway. "If scientific, technical, or other specialized knowledge will assist the trier of fact to understand the evidence or 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." Fed.R.Evid. 702. Despite its apparent breadth, this language does not give experts carte blanche, but, rather, envisions some regulation of expert testimony by trial judges. The Court's opinion in Daubert furnishes the principal source of guidance on the proper fulfillment of this gatekeeping role.

    We start with an historical perspective. Prior to Daubert, courts and commentators regarded Frye v. United States, 293 F. 1013 (D.C.Cir.1923), as the watershed case on the admission of expert opinion testimony. Under Frye, the admissibility of an expert opinion or technique turned on its "general acceptance" vel non within the scientific community. Id. at 1014. Daubert tackled the question of whether the Frye standard survived the passage of the Federal Rules of Evidence (and, in particular, Rule 702) and answered that question in the negative, holding that Rule 702 displaced the Frye test. See Daubert, 509 U.S. at 587-89, 113 S.Ct. 2786.

    The Daubert Court's interpretation of Rule 702, drawn from its text, requires the trial judge to evaluate an expert's proposed testimony for both reliability and relevance prior to admitting it. See id. at 589-95, 113 S.Ct. 2786. The requisite review for reliability includes consideration of several factors:

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    the verifiability of the expert's theory or technique, the error rate inherent therein, whether the theory or technique has been published and/or subjected to peer review, and its level of acceptance within the scientific community. See id. at 593-95, 113 S.Ct. 2786. The Court reasoned that due investigation of such matters will ensure that proposed expert testimony imparts "scientific knowledge" rather than guesswork. Id. at 592, 113 S.Ct. 2786. Withal, the factors that the Court enumerated do not function as a "definitive checklist or test," but form the basis for a flexible inquiry into the overall reliability of a proffered expert's methodology. Id. at 593, 113 S.Ct. 2786.

    Along with the reliability requirement, the Daubert Court imposed a special relevancy requirement. See id. at 591-92, 113 S.Ct. 2786. To be admissible, expert testimony must be relevant not only in the sense that all evidence must be relevant, see Fed.R.Evid. 402, but also in the incremental sense that the expert's proposed opinion, if admitted, likely would assist the trier of fact to understand or determine a fact in issue, see Daubert, 509 U.S. at 591-92, 113 S.Ct. 2786. In other words, Rule 702, as visualized through the Daubert prism, "requires a valid scientific connection to the pertinent inquiry as a precondition to admissibility." Id. at 592, 113 S.Ct. 2786.

    In General Elec. Co. v. Joiner, 522 U.S. 136, 118 S.Ct. 512, 139 L.Ed.2d 508 (1997), the Justices established the appropriate standard of appellate review for Daubert determinations, concluding that a reviewing tribunal should scrutinize a trial court's decision to allow or disallow the admission of expert testimony on Daubert grounds for abuse of discretion. See id. 118 S.Ct. at 517. Joiner also placed a gloss on Daubert 's insistence that trial courts focus on an expert's methodology, rather than his conclusions, in order to determine the reliability of his testimony. See Daubert, 509 U.S. at 595, 113 S.Ct. 2786. The Joiner Court moderated this position, acknowledging that

    conclusions and methodology are not entirely distinct from one another. Trained...

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