Pennsylvania Supreme Court Issues Landmark Decision On Admissibility Of Scientific Evidence

July 1, 2012

By: Paul Kenneth Vey

On May 23, 2012, the Pennsylvania Supreme Court in a unanimous 53-page decision in Betz v. Pneumo Abex,[1] which reversed the 2010 en banc panel of the Superior Court that overturned an Allegheny County trial court’s ruling on a Frye[2] motion in an asbestos product liability action.

At the trial court, the plaintiff alleged that Charles Simikian’s exposure to asbestos-containing friction products, such as brake linings, throughout his 44-year career as an auto mechanic caused his development of and eventual death from, mesothelioma.  The action was selected by plaintiffs among several pending asbestos-related lawsuits as a test case to consider challenges brought by defendants to the opinions and methodology supporting the plaintiffs’ theory that exposure to friction products was a proximate cause of asbestos-related disease.

In a new opinion, the Supreme Court of Pennsylvania in Betz v. Pneumo Abex has clarified the standards and procedure for trial judges to follow when acting as gatekeeper for novel expert testimony. The Betz case was designated by Judge Robert J. Colville and plaintiffs’ and defense counsel from a pool of similar asbestos cases pending in the Court of Common Pleas of Allegheny County. Two of the defendants in those cases had filed global motions to exclude expert testimony on the “single breath” theory of causation of asbestos related disease espoused by the plaintiffs’ experts. That theory, based on extrapolation, holds that the inhalation of just one asbestos fiber from an asbestos containing product, no matter what other asbestos exposure and extent of exposure the plaintiff may have had, causes asbestos related disease. The defendants argued that the theory was novel and not based on accepted scientific principles. Judge Colville instructed the parties to designate a case as a test case for the Frye challenge raised by the defendants. [A Frye challenge is the Pennsylvania state courts’ method of challenging expert testimony, as opposed to the federal courts which are governed by the U.S. Supreme Court’s decision in Daubert. While interesting, the distinctions between the two will not be discussed here.] In doing so, Judge Colville ordered the parties to exchange expert reports on the theory and held a full evidentiary hearing.

The Effect on Frye Hearings and Challenges to Expert Testimony

The mechanism to challenge expert testimony at trial is set forth in the Pennsylvania Rule of Civil Procedure 207.1 which states that when a party moves the court to exclude expert testimony which relies on novel scientific evidence, on the basis that it is inadmissible under Pa. Rule of Evidence 702 or 703, the court shall initially review the motion to determine if, in the interests of justice, the matter should be addressed prior to trial. The court, without further proceedings, may determine that any issue of inadmissibility of expert testimony be deferred until trial.

It is within the discretion of the trial court to determine what manner in which it determines the Frye motion. The Supreme Court’s official note to Rule 207.1 specifically states that the judge may choose to decide the motion prior to when the expert witness testifies at trial based on evidence offered outside of the presence of the jury, or after the expert witness has testified at trial, in which event the trial judge would strike the testimony of the expert witness if it is found to be inadmissible under Rule 702 or 703. Judge Colville explained his rejection of the plaintiffs’ expert’s extrapolation theory, using the analogy that very small amounts of alcohol or poison are not harmful, but that in large or very large amounts can injure or kill.

The Superior Court reversed Judge Colville’s ruling in Betz, criticizing his treatment of the Frye challenge, specifically, the finding of novelty and stated that he had abused his discretion in finding that the plaintiffs’ expert’s extrapolation based methodology was not generally accepted science.

In an earlier opinion the Superior Court has stated that a Frye hearing is not appropriate every time science enters the courtroom citing Commonwealth v. Dengler, 586 Pa. 554, 890 A.2d 372, 382 (2005). The Superior Court sitting en banc in Trach v. Fellin, 817 A.2d 1102, 1110 (Pa. Super. 2003) said to do so would be “a result that is nothing short of Kafkaesque to contemplate” painting the procedure as one of senseless complexity. This quote was not lost on the Supreme Court which quoted it at page 7 of its opinion in Betz in highlighting the plaintiff’s position.

The Superior Court panel in Betz noted that under Rule 207.1, as well as Grady v. Frito Lay, Inc., 576 Pa., 839 A.2d 1038 (2003) (a case involving the expert theory that Doritos are dangerously sharp) and Trach, a Frye motion requires the Court to engage in a two-step process. First, upon the filing of a Rule 207.1 Motion, the trial court must determine whether the evidence the moving party seeks to exclude is “novel scientific evidence.” To do so, the trial court must consider the proffered basis for excluding the evidence and the evidence presented in support of that basis, and decide whether the moving party has demonstrated that there is a legitimate dispute regarding the reliability of the expert’s conclusions. If the trial court determines that the Rule 207.1 motion has identified “novel scientific evidence,” then it must proceed to a second step, applying the Frye standard to decide whether the expert’s methodology “has general acceptance in the relevant scientific community.” Citing Grady, 756 Pa. at 555, 839 A.2d at 1043-44.

In Trach, a pharmaceutical product liability case, Judge Klein, in his dissenting opinion specifically criticized the trial judge for not conducting a Frye hearing, stating “from the record we cannot determine whether [the expert]’s testimony did or did not meet the Frye standard. Therefore, I would remand for a full Frye hearing. If it is determined that the Frye standard was met, there would be no need for a new trial. If the Frye standard was not met, then there should be a new trial.” 817 A.2d at 1120. Judge Klein explained:

Therefore, we as an appellate court cannot determine whether or not the basic premise upon which [plaintiff’s expert] extrapolated to reach his conclusion is generally accepted science. If it is, then the extrapolation is justified. If it is not, then the extrapolation fails because the basis of the extrapolation is not supported.

We have made the interpretation of the Frye principle far too complex. We should be able to come up with a commonsense approach to the “gatekeeper” function of the trial court when it comes to scientific evidence.

I believe we can conduct this analysis by following four simple principles.

  1. Frye applies to scientific testimony whenever there is a legitimate dispute as to whether the expert’s conclusions or methodology are generally accepted.
  2. If the expert’s conclusion is generally accepted, then there is no need to evaluate his or her methodology.
  3. If the expert’s conclusion is not generally accepted, then courts must determine whether the underlying methodology is reliable.
  4. The challenger bears the burdens of production and proof. The trial court should deny the motion without a hearing unless the movant has presented and supported a prima facie case that the evidence is not generally accepted.

817 A.2d at 1123. Judge Klein then immediately cited Rule 207.1 and its explanatory comment, which seems to provide the basis of his suggested procedure. At the end of his analysis under Frye, Judge Klein stated in any event, trial courts are to comply with Pa.R.Civ.P. 207.1, which provides that, where a party files a Frye motion with the trial court, the court, in its discretion, can hold a Frye hearing before trial, or defer it to trial, and further that nothing in the rule precludes raising the issue during trial. Judge Klein’s criticism of the trial court’s handling of the application of Frye in Trach was that the trial court denied the defendant’s motion in limine without a hearing, but then granted the defendant’s post trial motion which again raised the issue, also without holding a Frye hearing. Had the court held a Frye hearing, preferably at the motion in limine stage, or at least prior to reversing the verdict, the record would have been fully developed. 817 A.2d at 1126-1127.

It appears the Supreme Court in Betz has vindicated Judge Klein’s position in Trach, and brought the issue full circle, in that it is the en banc Superior Court’s acceptance of extrapolation methodology in Trach that the Superior Court relied on in reversing Judge Colville’s decision in Betz. The Supreme Court specifically approved of Judge Colville’s utilization of the Frye hearing pursuant to Rule 207.1 prior to trial and specifically commented that his ruling under Frye was supported by the record from the Frye hearing where experts called by plaintiff and defendants testified as to the methodology. In so doing, the Supreme Court noted Judge Shogan’s concurring opinion crediting Judge Colville for his well-intentioned and conscientious efforts to address a confusing area of the law arising in a mass tort setting. Betz, slip op. at 26.

Counsel should be prepared to challenge their opponents’ experts’ novel methodologies prior to trial with fully substantiated motions pursuant to Rule 207.1, and the trial court will be less likely to defer the issue of admissibility until hearing the expert’s trial testimony, given the Supreme Court’s holding in Betz. Although the Supreme Court of Pennsylvania has continued to reject adopting the Daubert standard, perhaps we will see Frye hearings scheduled in state courts as routinely as Daubert hearings are in the federal courts. The effect of the Betz ruling will not be limited to asbestos cases and can apply to any novel theory espoused by an expert.

Betz’s Potential Effect on Expert Witness Testimony

Rule 702 of Pennsylvania Rules of Evidence governs the admissibility of testimony by expert witnesses through the fulfillment of a well-established method of proof under the Fryestandard.  This standard, also referred to as the “general acceptance test,” provides that an expert opinion based on a scientific technique is admissible only where the technique is generally accepted as reliable in the relevant scientific community.  Under Pennsylvania’s formulation of the Frye test, this demonstration will usually involve a showing that there is a general acceptance with the relevant scientific community that a procedure, test or experiment is reliable and is able to be conducted in such a way as to yield an accurate result.

Although strict reliance on the Frye standard was abandoned by the United States Supreme Court in Daubert v. Merrill Dow Pharmaceuticals, Inc., 509 U.S. 579 (1993), the Pennsylvania Supreme Court has since affirmed that the Frye test would remain the Commonwealth standard[3]; directing trial courts within the state to remain steadfast in applying this standard to analyze an expert’s methodology, not the expert’s conclusions.  Un-departing from this directive, Betz reaffirms Pennsylvania’s adherence to this principle.

In so holding, Justice Thomas G. Saylor, writing for a unanimous Court, clarified that trial courts’ decisions to conduct Frye hearings are appropriate in an era where scientific methods are being utilized in novel ways in complex litigation.  To the same end, Betz recognizes the need to have a reasonably broad meaning to ascribe the term “novel” and further mandates that trial courts should reach an informed assessment by undertaking a “thoughtful inquiry” of the expert’s purported methodology.  Particularly to this note, Justice Saylor acknowledged that Judge Colville was right to be “circumspect about the scientific methodology underlying the any-exposure opinion” where Plaintiffs/Appellees’ presented contradictory expert testimony – opining that mesothelioma is dose-responsive and also that each and every fiber among millions is substantially causative.  In sum, Betz now provides precedent that a Fryehearing is warranted where there is reason to question novel scientific evidence which may only be employed later at trial as a tool to confuse and mislead a jury.[4]

Finally, the implications of Betz most notably impact Pennsylvania law by providing precedent which requires the proponent to come forward with concrete scientific evidence before it can be put before a jury.  No longer should a party be able to evade a Frye hearing with expert opinions that are as strong as castles made of sand.

Instead, Betz reiterates and reinforces the holdings in Gregg v. V-J Auto Parts, Co., 596 Pa. 274, 291, 943 A.2d 216, 226 (2007) and Summers v. Certainteed Corp., 606 Pa. 294, 317, 997 A.2d 1152, 1165 (2010) that with Frye hearings, generalized opinions cannot suffice to create a jury question in complex litigation where product identification is de minimus, particularly with the absence of evidence excluding other possible sources of exposure.

Betz’s Potential Effect on Asbestos Litigation

While there is quite a lot in the Betz decision to applaud, it is unlikely that this decision spells the end of the low-dose defendants’ potential liability, particularly in mesothelioma cases. Most assuredly, however, the Betz decision makes plaintiff counsel’s job more difficult.

The Supreme Court dodged the question that many had hoped it would address- the question of whether there is any scientific support for the assertion by plaintiffs’ experts that chrysotile asbestos fibers are capable of causing mesothelioma. Friction defendants, most of whom have solid evidence that their products contained only chrysotile, assert that their product is incapable of causing or contributing to lung disease- an assertion that is well-supported in peer-reviewed scientific studies. Unfortunately, the Court declined to address this issue. Betz, 2012 WL 1860853 at *1.

Rather, the Supreme Court focused on the limitations of the report of a pathologist, Dr. Maddox and the shortcomings of his methodology, and even his logic, in offering a “general” causation opinion.  As the plaintiffs adapt to the Supreme Court’s decision, it is anticipated that instead of using experts who offer “general” causation opinions from a pathologist, such as Dr Maddox, as they did in the Betz case, they will solicit expert reports in which an epidemiologist offers the opinion that the plaintiff’s exposure, however slight, constitutes exposure above the “background” exposure.  It cannot only be expected that plaintiffs will then try to rely on the Pennsylvania Suggested Standard Civil Jury causation instruction regarding “increased risk of harm.”  Plaintiffs’ experts will opine that the exposure was a substantial factor in causing disease in the plaintiff because the exposure beyond background increased the risk of harm; i.e., increases the incidence of disease. This approach of course, once again, begs the question- how much exposure is the necessary exposure, beyond background, that is sufficient to create/contribute to disease.

In the end, while extremely helpful, the Betz decision simply may represent the first of several battles at the courtroom door over the “science” of exposure, and hence causation. Rarely are the plaintiffs able to locate a coworker who has any reliable knowledge of the deceased’s exposure to a low-dose defendant’s product(s). Under Betz, an epidemiologist should not be able to “assume” exposure based solely on lay-testimony so as to express an opinion of exposure beyond background and therefore provide causation.

Can friction material exposed to high temperatures create exposure? The defense says, “No.” The plaintiff’s epidemiologists and industrial hygienists will say, “Yes.”

The next battle may be just around the corner. But, we are heartened that the Betz decision increases the awareness of all trial courts to “science” about which they rightly should express significant skepticism.

Betz’s Potential Effect on Product Liability and Medical Device Litigation

For quite some time, asbestosis and product liability cases have been inextricably intertwined.  It should come as no surprise that the Court’s analysis in Betz will impact both product liability and medical device cases alike.  As we are all aware, the courts in Pennsylvania generally require expert testimony in both product liability and medical device cases given that the science in both are almost always outside the general knowledge of a lay person.  And like other cases, the methodologies behind expert testimony given in product liability cases are often challenged.

For example, in Grady, the Supreme Court considered whether the trial court properly applied the Frye test in a product liability case in which the plaintiff’s expert opined that Doritos remained too hard and sharp – and, therefore, dangerous – as they are chewed and swallowed.  Applying the Frye test, the trial court found that the expert’s “methodology smacked of a high school science fair project and did not bear any relationship to the reality of mastication and consumption of foodstuffs.”  Grady, 576 Pa. at 553.  Not surprisingly, the trial court did not conduct a Frye hearing but, rather, decided the issue on briefs and oral argument.  The Superior Court reversed, finding that the tests performed by the expert utilized the scientific methodology.  The Supreme Court ultimately reversed the appellate court and found that the trial judge had appropriately applied Frye and determined that “while the expert’s calculations may in fact represent a standard method that scientists use to reach a conclusion about the downward force needed to break Doritos, they are not also necessarily a generally accepted method that scientists use for reaching a conclusion as to whether Doritos remain too hard and too sharp as they are chewed and swallowed to be eaten safely.”  Grady, 576 Pa. at 551.

So how is Betz likely to affect product liability and medical device cases when many trial courts are already applying Frye to expert testimony in product liability and medical device cases?

The Court’s decision in Betz adds support for trial court judges faced with expert opinions proffered on questionable scientific methodology.  Like Grady, many trial courts question the reliability of scientific opinions and methodologies in product liability cases.  Many, however, do not and prefer to let jurors decide whether the methodologies and science are credible.  The Supreme Court recognized as much when it stated, “[f]or better or for worse, however, in the context of more conventional realms of science, the Pennsylvania decisions tend to downplay the courts’ screening functions.”  Betz, 2012 WL 1860853 at *20.  The Betz Court has clearly signaled to the trial courts that they are free to conduct Frye hearings if there are “articulable” grounds to believe that the expert has not applied accepted scientific methodology in a conventional fashion in reaching his or her conclusions.  Id.

The easing of the preference to limit the courts’ involvement in determining the admissibility of scientific evidence will likely lead to more Frye challenges and hearings in both the general product liability realm and in medical device cases.  While this change may not occur overnight, we expect that the trial courts will slowly catch on and become more willing to scrutinize the opinions and underlying methodologies of product liability experts and experts in general.  Put simply, Betz appears to create a safe harbor for trial court judges that are willing to scrutinize an expert’s opinions and methodologies, as long as there is an articulable reason to do so.  In summary, the Court’s decision in Betz may herald a return of the trial courts to their gate keeping role when addressing expert testimony.


While it is still too early to state the affect that this landmark decision will have on the qualification and admissibility of expert witness testimony, it is not too early to conclude that the far-reaching implications will change the legal landscape for years to come.


[1] Betz v. Pneumo Abex, 38 WAP 2010, 2012 WL 1860853 (Pa. May 23, 2012)

[2] Frye v. U.S., 293 F. 1013 (D.C. Cir 1923)

[3] Grady v. Frito-Lay, Inc., 576 Pa. 546, 839 A.2d 1038 (2003) (rejecting the Daubert standard applicable in federal courts and reaffirming adherence to the Frye rule: clarifying that the rule applies to an expert’s methods, not the expert’s conclusions, emphasizing that the proponent of the expert scientific evidence bears the burden of proof and the standard of appellate review on the Frye issue is the abuse of discretion standard).

[4] As an aside, in addressing the expert’s methodology Betz further directs practitioners’ to challenge expert testimony through analyzing the expert’s background and particular field of science.  Through this application the Supreme Court affirmed that methodologies (Plaintiffs/Appellees’ any-exposure opinion) not specifically related solely through the practice of a particular profession – pathology could also be addressed by interdisciplinary professional testimony (of risk assessors, toxicologists and epidemiologists).

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