By Patrick Malone 

 

The adage “No expert, no case” has new meaning for Maryland trial lawyers since the Maryland Supreme Court’s adoption of the Daubert standard in 2020. Here is an exclusive pre-release of an article by MAJ member Patrick Malone that comprehensively reviews the Maryland case law on expert witness admissibility and provides useful tips for how to navigate these perilous waters. This article will be published in the 8^th Edition of Maryland Tort Damages, scheduled to be released in 2024. Maryland Tort Damages is published by the MSBA. According to the publisher, “[s]ince the First Edition was published in 1979, Maryland Tort Damages has provided a comprehensive and detailed analysis of the most important legal issues and practical considerations surrounding Maryland tort damages, plus a thorough overview of related Maryland statutory and case law.” 

The gatekeeping rules for when Maryland courts will allow an expert to give opinions at trial about the nature and extent of a plaintiff’s damages in a tort case have undergone a sea change. In August 2020, the Maryland Supreme Court ended years of what it called “jurisprudential drift” away from its old Frye/Reed standard for expert witness admissibility by explicitly dropping Frye/Reed and adopting the federal Daubert standard. In Rochkind v. Stevenson, 471 Md. 1, 236 A.3d 630 (2020) (Rochkind II) ⁱ, the high Court said that from now on, Maryland state courts would follow the more flexible, yet often more exacting, Daubert test. Where the Frye/Reed test looked to whether an expert’s methodology was “generally accepted” in the expert’s field, the new test looks to the reliability of the expert’s methods and their factual underpinnings. In many cases, this requires lengthy written submissions and oral hearings. But the new test resists neat summary and in many respects awaits further case law for clarity. 

 

The New Daubert Standard for Expert Witness Admissibility in Maryland State Courts 

The black-letter rule of expert admissibility in the Maryland Rules of Evidence remains the same text as when adopted in 1994: 

Expert testimony may be admitted, in the form of an opinion or otherwise, if the court determines that the testimony will assist the trier of fact to understand the evidence or to determine a fact in issue. In making that determination, the court shall determine 

(1) whether the witness is qualified as an expert by knowledge, skill, experience, training, or education, 

(2) the appropriateness of the expert testimony on the particular subject, and 

 (3) whether a sufficient factual basis exists to support the expert testimony. 

Md. Rule 5-702 (2021 ed.).  

After its Rochkind II decision in 2020, the Maryland Supreme Court rejected a proposed amendment to Md. Rule 5-702 that would have codified Rochkind II’s criteria for admissibility with language from that decision and from Fed. R. Evid. 702 focusing on the reliability of the expert’s methods and conclusions.ⁱⁱ The Court elected instead to keep the existing text of Md. Rule 5-702 and amended it only by (1) striking the old Rule’s committee note that had stated the Rule didn't represent an overruling of Reed or an adoption of the federal Daubert standard, and (2) replacing that committee note with this: “Cross reference: See Rochkind v. Stevenson, 471 Md. 1 (2020).”  

Most of the focus in Maryland state courts following Rochkind II and the amended Md. Rule 5-702 concerns the “sufficient factual basis” prong of the Rule. In Rochkind I, the Court had already said that “sufficient factual basis” has two elements: “(1) an adequate supply of data; and (2) a reliable methodology,” a holding it re-emphasized in Rochkind II. Yet, the Maryland Supreme Court has made it clear that a trial court’s gatekeeping function requires a more elaborate inquiry as to whether an expert’s opinion has a “sufficient factual basis” than the plain language of Md. Rule 5-702 suggests. Not only did the Maryland Supreme Court in Rochkind II adopt Daubert and its federal caselaw progeny, but in its August 2023 Parkway decision, the Court praised amendments to Fed. R. Evid. 702 that admonish trial courts not to skip or go lightly with their gatekeeping requirement. Katz, Abosch, Windesheim, Gershman & Freedman, P.A., v. Parkway Neuroscience and Spine Institute, LLC, 485 Md. 335, 301 A.3d 42 (2023).iii Thus Maryland courts and trial practitioners now have a vast body of federal and state law to draw on in litigating expert admissibility issues in state courts. Moreover, cases that used the Frye/Reed analytical framework remain relevant because a methodology’s “general acceptance” is one of the listed factors (No. 5) in the Daubert analysis, although it is no longer the sole touchstone. 

 

Lead Poisoning and Beyond: Rochkind and its Progeny, 2020-2024 

The Maryland Supreme Court ’s Daubert jurisprudence started with pediatricians testifying in lead poisoning cases and soon expanded to forensic experts in criminal trials, oral surgeons in a medical malpractice case, and an accountant estimating lost business profits. Its decisions have been notable for an intense focus on the details of an expert’s opinions, with slip opinions often clocking in at 50 to 60 pages or more. And, in all five of the reported decisions since Rochkind II, the Maryland Supreme Court reversed the trial court, the Appellate Court of Maryland, or both. 

The Rochkind decisions, and a case decided between them, Sugarman v. Liles, 460 Md. 396, 190 A.3d 344 (2018), plus another decided in 2023 (Oglesby v. Baltimore School Associates, discussed below), concerned small children who suffered lead poisoning from exposure to lead-based paint on interior surfaces of places they resided. Could these children, many now in their teens and 20s, claim damages from the building owners or managers for issues including attentional deficits and hyperactive and impulsive behaviors? The specific expert admissibility issues in those cases centered on: (1) whether the plaintiff had enough evidence of exposure to lead in the defendant’s building to enable an expert to connect the plaintiff’s elevated blood lead levels to the defendant (sometimes called exposure causation); (2) how national studies of lead poisoning in children could be used, if at all, to causally link the plaintiff’s specific learning and behavioral disorders to their lead exposure; (3) whether national studies of loss of IQ in children correlated with their blood lead levels could reliably be used to estimate IQ loss in the plaintiffs, and (4) the reliability of expert testimony on loss of earning capacity by vocational rehabilitation counselors basing their opinions on pediatrician opinions about learning and behavioral disorders in the same plaintiffs. 

In the Rochkind decisions, the Court twice held that the plaintiff’s evidence, mainly from a lengthy published analysis by the Environmental Protection Agency (known as the EPA-ISA document), that lead exposure was associated with cognitive and behavioral problems in general did not support extrapolating a causal link to the plaintiff’s Attention Deficit Hyperactivity Disorder (ADHD). After the first Rochkind decision, the trial court held a new trial on damages in which the expert was allowed to testify that the plaintiff had a brain injury from lead exposure that showed itself in symptoms of attention deficits, hyperactivity and impulsivity, but the expert did not opine, as she had in the previous trial, that the plaintiff had actual ADHD.  In Rochkind II, after the adoption of the Daubert standard, the Maryland Supreme Court remanded the case for a pretrial hearing to give the plaintiff’s expert a chance to explain her reasoning linking the general evidence of causation to the plaintiff’s symptoms. The Supreme Court also criticized the trial court for refusing the defendant’s request to hold such a hearing outside the jury’s presence, holding that the trial court’s refusal constituted an “abuse of discretion.” 471 Md. at 26-27, 236 A.3d at 645.  

In Sugarman, by contrast, the Maryland Supreme Court said the plaintiff’s expert had successfully bridged the “analytical gap” between general and specific causation evidence. The plaintiff in Sugarman had undergone neuropsychological testing that revealed significantly low scores on “auditory encoding” and “processing speed,” two components of attention. The defendant’s contended that the plaintiff’s analysis was fatally flawed because the EPA-ISA document didn't break down the components of attention that it found were impacted by lead poisoning, and thus, one couldn't be sure that “auditory encoding” and “processing speed” were part of the EPA’s attention-deficit analysis of general causation. In rejecting the defendants’ argument, the Court held both the challenged pediatrician expert and plaintiff’s neuropsychology expert both “testified that deficits in auditory encoding and processing speed are ‘factors of attention.’ They also described how those deficits were related to attention. Although the literature does not mention these particular deficits, both experts testified that they were within the realm of general attention deficits, and the literature does state that general attention deficits can result from lead exposure.” Sugarman, 460 Md. at 428, 190 A.3d at 362.iv The Court also allowed the testimony of plaintiff’s vocational rehabilitation expert on lost earning capacity, rejecting the defendant’s criticism that the expert had failed to take account of the plaintiff’s parents’ lack of college education in opining that the plaintiff would have earned a college associate degree but for the lead poisoning. 

The appellate courts show a preference for leaving disputed issues to the jury, as long as the expert is shown to be qualified and has crossed a (somewhat ill-defined) threshold of reliability. As the court stressed in separate passages in Sugarman: “Sugarman presented contradictory experts and extensively cross-examined Liles's experts about their conclusions. That is what we contemplated in Levitas and Roy” Id. at 437, 190 A.3d at 368; and: “Legitimate scientific disputes go not to the admissibility of testimony, but to the weight of the evidence.” Id. at 434, 190 A.3d at 366.  

In both the Roy and Levitas cases, the Maryland Supreme Court approved as admissible the opinions of experts who testified that the plaintiff had lost specific numbers of IQ points based on their blood lead levels. “Levitas and Roy demonstrate that a properly qualified expert witness can rely on the Lanphear Study methodology, as well as other accepted scientific research, as a factual basis for an opinion that a plaintiff's elevated BLLs caused the loss of a specific number of IQ points.” Id. at 434, 190 A.3d at 366.v  

More recently, the Maryland Supreme Court took up the same lead poisoning literature in reversing a trial court’s exclusion of a plaintiff’s expert and summary judgment in Oglesby v. Baltimore School Associates, 484 Md. 296, 298 A.3d 859 (2023). The Court held the trial court erred in excluding plaintiff’s pediatrician expert for not doing his own examination of the plaintiff and instead relying on reports of other doctors. As to the use of the study that formed the basis of the expert’s opinion about the plaintiff’s loss of IQ, the Court noted:  

with respect to the Lanphear study, Respondents identify a statement in the study that “[t]he observational design of this study limits our ability to draw causal inferences” and argue that this language renders Dr. Caplan’s opinion concerning Ms. Oglesby’s IQ loss inadmissible….Our case law contradicts the notion that expert testimony as to specific causation in reliance on the Lanphear study is precluded based solely on the language in the study that Respondents point out and suggests that the significance of the language the Respondents point out is a matter for cross-examination. 

Id. at 355, 298 A.3d at 895. 

The Oglesby Court addressed several other criticisms of the plaintiff’s expert by remanding for a Rochkind hearing on the reliability of the expert’s methodology for calculating IQ loss in the plaintiff. Id. at 358, 298 A.3d at 897.  

 

Other Expert Admissibility Decisions since Rochkind II  

As of this writing (June 2024), the Maryland Supreme Court has revisited expert witness admissibility in the following cases since its Rochkind II decision:  

• Oglesby, discussed above, reversing a trial court’s exclusion of an expert (and reversing as well the Appellate Court’s affirmance) and remanding for a Rochkind hearing. As in Frankel v. Deane, discussed below, the Maryland Supreme Court found that the trial court had impermissibly resolved disputed issues of fact when it ruled that the plaintiff’s expert must be excluded because his facts about the child’s exposure to lead were arguably “incorrect” according to the defense.  

• State v. Matthews, 479 Md. 278, 277 A.3d 991 (2022). In this murder case, the trial court allowed an FBI scientist to testify about the height of a person seen on a surveillance video footage at the scene, using a technique called “reverse projection photogrammetry.” Maryland’s intermediate appellate court had reversed the conviction, holding that the inability of the expert to give a range of height estimates based on the technique’s variables was fatal to the reliability of the measurement. The Maryland Supreme Court reversed the intermediate appellate court and reinstated the conviction, holding that the expert’s inability to quantify all the variables did not render her testimony unreliable.vi  

• Abruquah v. State, 483 Md. 637, 296 A.3d 961 (2023). The Maryland Supreme Court found the trial court’s admission of a firearms examiner’s opinion to be an abuse of discretion. The high court reversed the defendant’s murder conviction on the ground that the firearms examiner overstated the certainty of his conclusion when he testified without qualification that a bullet found at the crime scene had come from the defendant’s gun, as opposed to saying that the markings on the bullet were consistent with having come from the gun. 

• Frankel v. Deane, 480 Md. 682, 281 A.3d 692 (2022). The Maryland Supreme Court, as did the Maryland Appellate Court before it, reversed the trial court’s exclusion of an expert witness in a dental malpractice case and also reversed the grant of summary judgment. The trial court said the expert had made a fatal misstep by accepting the plaintiff’s testimony that her tongue numbness never improved after a wisdom tooth extraction when the expert had not reviewed what the defendant dentists had written in their records, that she told them the numbness was improving. The two appellate courts said the trial court abused its discretion by choosing sides in a credibility battle between the defendants and the plaintiff over disputed facts, and that this impermissibly gave the defendants “the benefit of favorable inferences drawn from evidence susceptible to more than one interpretation.” 480 Md. at 700, 281 A.3d at 705. 

• Katz, Abosch, Windesheim, Gershman & Freedman, P.A., v. Parkway Neuroscience and Spine Institute, LLC, 485 Md. 335, 301 A.3d 42 (2023) (referred to herein as Parkway). This accounting malpractice case concerned a multi-specialty medical practice that sued its former accounting firm alleging that the accountants’ mismanagement caused a mass exodus of physicians from the practice. The practice sued the accountants for lost profits. The trial court excluded the plaintiff’s CPA expert from opining on the medical practice’s lost profits, for, among other reasons, making an arbitrary choice of base years to use for a before-and-after comparison. The Maryland Appellate Court reversed and held that the expert’s choice of base year wasn't arbitrary and didn't make her opinion unreliable. The Maryland Supreme Court reversed the Appellate Court and held that trial court had been mostly correct in its analysis of the expert’s proposed testimony. But the Supreme Court remanded the case on the limited issue of whether the trial court’s decision had given too much weight to one factor in which the Supreme Court said the trial judge had erred: criticizing the expert for amending her report after finding errors in the earlier version. The Court said an expert’s willingness to admit and fix errors did not cast doubt on the reliability. 

Readers will notice that in EVERY case in the four years after Rochkind II – as well as in the two Rochkind decisions themselves – the Maryland Supreme Court held that either the trial court, the intermediate appellate court, or both had gotten the expert witness analysis wrong. To put it mildly, the era of routine affirmances of trial court decisions on expert admissibility has not yet arrived in Maryland. 

 

Facts versus Methodology: A Safe Harbor for Experts?  

One point that is especially elusive under the current state of the law is whether there are any “safe harbors” of categories of data or types of methodology that will give reassurance that an expert is not vulnerable to a Rochkind-type exclusion. The short answer is “no.”  

In Parkway, for example, the Appellate Court of Maryland and the Maryland Supreme Court differed on the key issue of what counts as facts versus methodology – factual disputes being for juries to decide whereas methodology being in the court’s domain. The intermediate court said that the accounting expert’s choice of base year for her before-and-after profits analysis was a factual underpinning that could be subject to cross-examination at trial but was not part of her methodology and thus was outside the gatekeeping purview of the trial court. The Maryland Supreme Court disagreed. It characterized the approach of the intermediate appellate court as “rigid” in demarcating the fact/method border, whereas its own approach and that of the trial court was “flexible.” In adopting a more fluid approach, the Maryland Supreme Court observed: “In short, whether an expert’s methodology is sufficiently reliable to admit the expert’s testimony at trial will sometimes require a trial court to consider data and assumptions that the expert has employed in deciding threshold points relating to the methodology.” 485 Md. at 376, 301 A.3d at 66.  

Turning to the specifics of the Parkway case, the Supreme Court found that the heart of the trial court’s decision to exclude the expert was that the expert’s choice of which years to use for her benchmark in the lost profits analysis rested on “speculative, insufficiently substantiated judgment calls” whose validity was “impossible to test.” Id. at 377, 301 A.3d at 67. The high court concluded: “We rely on trial courts that conduct Daubert-Rochkind hearings to determine where the line between data and methodology is in the specific cases before them, and whether the proffered expert’s choices relating to data, assumptions, and other inputs implicate the reliability of the expert’s methodology.” Id. at 378, 301 A.3d at 67. 

By contrast, in the lead paint cases such as Oglesby, the Maryland Supreme Court more readily embraced the idea that it was not for the trial court to examine the factual basis for the expert’s conclusion about a child’s lead exposure, when there were facts in dispute. That is especially so when the resolution of those factual disputes depends on fact witnesses’ credibility, a classic domain for the jury. A similar approach was taken by the Maryland Supreme Court in Frankel v. Deane, 480 Md. 682, 281 A.3d 692 (2022), when it reversed a trial court for abusing its discretion in the context of an expert admissibility dispute, by deciding that the expert’s methodology was unreliable in what boiled down to a disputed fact issue about whether to credit the defendant dentist’s records or the testimony of the patient.  

The lesson for practitioners from comparing Parkway to Oglesby and Frankel is that disputes over whether an expert relied on the wrong facts usually are left to a jury to resolve when the underlying facts are capable of traditional jury considerations of credibility and weight of evidence. But choices by an expert about what facts to rely on will enter the expert admissibility analysis when, as in Parkway, the jury has no way to resolve the factual dispute on its own.  

 

Pre-Rochkind Cases that are Still Relevant for Analysis of “Reliable Methodology” and “General Acceptance”  

While the “general acceptance” of a particular scientific technique is no longer the sole deciding factor in Maryland expert witness admissibility decisions, the factor remains one of the ten flexible markers (No. 5) approved by the Maryland Supreme Court in Rochkind and later expert cases. In addition, Maryland courts in the 20 years before Rochkind had increasingly adopted a Frye/Reed-plus standard that looked to “reliable methodology” as part of the evidence rule’s test for an expert’s “sufficient factual basis.” For those two reasons, appellate decisions in Maryland predating Rochkind II remain relevant to the extent they elucidate what “general acceptance” means and what “reliable methodology” should include when analyzing whether an expert has a “sufficient factual basis” to support their opinions. 

In Carter v. Shoppers Food Warehouse, 126 Md. App. 147, 727 A.2d 958 (1999), the Court of Special Appeals affirmed a trial court’s rejection of a safety expert’s proposed testimony for a plaintiff who slipped and fell in a grocery produce section allegedly due to a sub-standard floor mat. The intermediate appellate court held that the expert’s opinions were inadmissible because the expert had inspected the store for only 15 minutes, four years after the accident, and based his opinion on floor mats that were supplied by a different company than the ones in place when the plaintiff had fallen. The expert also could point to no written standards in the industry for the required sturdiness of produce section floor mats. All these factors were fatal to the sufficiency of the factual basis for the expert’s opinion. 

In Wood v. Toyota Motor Corp., 134 Md. App. 512, 760 A.2d 315, cert. denied, 362 Md. 189, 763 A.2d 735 (2000), the intermediate appellate court affirmed a trial court’s rejection of a mechanical engineer’s opinion that an air bag was defectively designed because it caused chemical burns to the plaintiff’s face when it deployed. The expert was not sufficiently qualified, because all his knowledge about air bags derived from litigation, not experience in the automobile industry. This “expert” was excoriated because he “had not (1) interviewed nor spoken to the plaintiff, (2) read the plaintiff’s deposition, (3) talked to any of the other witnesses or any other parties, or (4) reviewed the police report. In fact, [the expert’s] total inspection of the air bag in this case . . . was one half hour or maybe even less.” Id. at 524, 760 A.2d at 322. The expert also had “provided no rational explanation” for his conclusion that the size and location of the air bag’s vent holes caused the plaintiff’s injuries. He did not even know which way the vent holes were pointed. Id. at 523–24, 760 A.2d at 322. The court concluded the expert’s testimony “was properly excluded for lack of an adequate methodology.” Id. at 527, 760 A.2d at 323. Wood was the first appellate decision in Maryland announcing methodology as part of the “sufficient factual basis” element of Md. R. Evid. 5-702. Indeed, the decision went so far as to proclaim that Maryland case law is “consistent with” the amendment to Fed. R. Evid. 702 that codified the Daubert standard for federal courts. Id. at 523 n.13, 760 A.2d at 322 n. 13. The Wood case foreshadowed the shift by Maryland state courts toward the Daubert-style scrutiny of experts that would be adopted by the Supreme Court in Rochkind II. 

In Giant Food, Inc. v. Booker, 152 Md. App. 166, 831 A.2d 481, cert. denied, 378 Md. 614, 837 A.2d 926 (2003), the Court of Special Appeals reversed a trial court for refusing to set aside a verdict based upon an expert’s unsubstantiated opinion. The expert was a pulmonologist who testified that his patient’s asthma was caused by his exposure 14 months previously to a release of Freon gas at a Giant Food ice plant. Cross-examination brought out that the doctor had no knowledge of the specifics of the exposure, had seen no medical literature that Freon could cause asthma, and could not explain why the patient had no wheezing or other lung-related symptoms in the emergency room immediately after the accident or when examined a month later. The Court of Special Appeals concluded that the expert’s testimony “amounts to a ‘because I think so,’ or ‘because I say so,’ situation.” Id. at 188, 831 A.2d at 493. 

The court also said the expert’s approach was “woefully inadequate” in that he failed to do any kind of systematic, much less exhaustive, review of the medical literature to find any basis to support his opinion. Id. at 189, 831 A.2d at 494. The court ultimately concluded that his testimony “lacked a sufficient factual basis and reliable methodology.” Id. at 190, 831 A.2d at 495. 

In two cases in 2002, the Court of Special Appeals rejected expert opinions that it found lacked sufficient factual support. Smith v. Dodge Plaza Ltd. P’ship, 148 Md. App. 335, 811 A.2d 881 (2002), concerned the landlord of a nightclub that was sued for failing to prevent one patron from being stabbed by another. Summary judgment for the landlord was affirmed, mostly on the basis of a “no legal duty” analysis, but the court also considered and rejected the testimony of the plaintiff’s security expert. The expert had opined that it was an industry custom for commercial landlords to make sure their tenants provided adequate security. The court held: “[t]he statement is entirely conclusory. Brill [the expert] furnishes no facts or specific examples to support the asserted custom.” Id. at 354, 811 A.2d at 892. 

In Days Cove Reclamation Co. v. Queen Anne’s County, 146 Md. App. 469, 807 A.2d 156 (2002), the court reversed a county board decision denying a landfill permit on the basis of an environmental expert’s conclusion that the landfill could pose pollution hazards. The court reviewed the expert’s opinion in detail, pointed out that his conclusion rested on a series of factual assumptions about the presumed future failure of protective liners, and rejected the opinion as “speculation.” Id. at 490, 807 A.2d at 169. 

In both Days Cove and Smith v. Dodge Plaza, the court cited a series of its own cases, including Wood v. Toyota, in which expert opinions had been rejected for lack of an adequate factual basis.  

In Blackwell v. Wyeth, 408 Md. 575, 584, 971 A.2d 235, 240 (2009), the Maryland Supreme Court held that the testimony of plaintiff’s expert Dr. Mark Geier—that vaccines with thimerosal were linked to autism in certain genetically susceptible individuals—was inadmissible in a product liability suit brought against a vaccine manufacturer by the parents of a child with autism, due to an “analytical gap” in Dr. Geier’s studies. The Court affirmed the trial court’s entry of summary judgment after precluding Dr. Geier’s testimony on the grounds that the causal connection between thimerosal and autism is not generally accepted in the relevant scientific community. The Supreme Court noted that several leading medical organizations rejected the plaintiffs’ theoretical link between thimerosal-containing vaccines and autism, including the Global Advisory Committee on Vaccine Safety, the Centers for Disease Control and Prevention, and the American Academy of Pediatrics. The only published epidemiological studies purporting to show a causal link between thimerosal-containing vaccines and autism were studies undertaken by Dr. Geier, which the trial court concluded did not pass scrutiny under Frye-Reed because the studies “have been rejected by the relevant scientific community due to severe methodological flaws that render them unreliable.” 

The Court stated that generally accepted methodology “must be coupled with generally accepted analysis in order to avoid the pitfalls of an ‘analytical gap.’” Here, the Maryland Court of Appeals concluded that the bases of Dr. Geier’s opinion, including the theory of causation, and the methodologies, were not generally accepted as reliable within the expert’s particular scientific field, and the data he relied upon were neither tested nor gathered for the purpose of testing the hypothesis that thimerosal in vaccines causes autism. None of Dr. Geier’s research aimed at establishing a link between thimerosal and autism, moreover, was based upon sound methodology, the Court held. Id. at 608–09, 971 A.2d at 255. 

In Chesson v. Montgomery Mut. Ins. Co., 434 Md. 346, 360, 75 A.3d 932, 939 (2013), the Maryland Supreme Court ruled that, under Maryland’s Frye-Reed standard, continued controversy in the relevant scientific community regarding a scientific theory rendered an expert’s testimony based on that controversial theory inadmissible. The plaintiffs, former employees of the Baltimore-Washington Conference of the United Methodist Church, alleged that they had sustained an injury or occupational disease known as “sick building syndrome” as a result of mold exposure in the defendant’s water-damaged building. Plaintiffs offered the testimony of Dr. Ritchie Shoemaker, a family physician and self-professed expert on mold, on the issue of causation. 

The defendant moved to exclude Dr. Shoemaker’s testimony on the basis that it was not generally accepted by the medical and scientific community and, therefore, was inadmissible under Frye-Reed. The trial court denied the motion, without holding a Frye-Reed hearing, and judgment was entered against the defendant after a trial on the merits. On the first appeal, the Court of Appeals remanded to the trial court for a Frye-Reed hearing, because “Dr. Shoemaker employs medical tests to reach a conclusion that is not so widely accepted as to be subject to judicial notice of reliability.” Montgomery Mut. Ins. Co. v. Chesson, 399 Md. 314, 332, 923 A.2d 939, 949 (2007) (Chesson I). 

In the trial court’s subsequent Frye-Reed hearing, Dr. Shoemaker testified about his medical opinions, citing support from his own articles regarding his methodologies and theories, which were collectively referred to as the “Repetitive Exposure Protocol” (REP). Defendant presented controverting evidence from Dr. Hung Cheung, who testified that the REP was not generally accepted as a valid protocol in the relevant scientific community, mainly due to its failure to measure the actual levels of mold exposure by individuals in the water-damaged building. 

Dr. Cheung further testified that the medical literature showed that Dr. Shoemaker’s process and theory were never generally accepted, and that the process contained critical analytical gaps. The trial court held that “Dr. Shoemaker’s ‘Repetitive Exposure Protocol’ was a differential diagnosis, which itself was ‘reliable’ and ‘properly performed,’ bringing it within general acceptance of the relevant scientific community.” On appeal, the Court of Special Appeals overturned the ruling, and the Court of Appeals granted certiorari for its second review of the case. 

In Chesson II, the Supreme Court concluded that “Dr. Shoemaker’s technique, which reflects a dearth of scientific methodology, as well as his causal theory, therefore, are not shown to be generally accepted in the relevant scientific community.” Chesson v. Montgomery Mut. Ins. Co. 434 Md. 346, 380, 75 A.3d 932, 951 (2013). The Court explained that “[g]eneral acceptance does not equate to unanimity of opinion within a scientific community, nor universality, and is not subject to a quantum analysis” but noted that “in testing the general acceptance in the relevant scientific community, methodology is a key component.” Id. at 373, 75 A.3d at 947. The court looked to published scientific literature, which revealed that Dr. Shoemaker’s theory, and the methodology behind it, was not generally accepted in the scientific community, and further noted that other jurisdictions that adhered to the more flexible Daubert standard had determined that Dr. Shoemaker’s theory was neither generally accepted nor reliable. See Young v. Buron, 567 F. Supp. 2d 121, 130–31 (D.D.C. 2008) (also listing Virginia, Florida, and Alabama as jurisdictions rejecting Dr. Shoemaker’s theory and excluding his testimony). 

In short, the pre-Rochkind cases show the careful and thorough work necessary for an expert to be allowed to testify at trial. Expert witnesses who do “quick and dirty” investigations (Carter), who fail to consider all the important facts (Booker), who proffer fringe theories criticized by leading scientific organizations (Blackwell and Chesson), who fail to look up relevant medical literature (Booker), who lack key data on toxin exposure (Chesson), and who fail to explain the detailed basis of their opinions (Wood and Smith) put themselves in jeopardy of being excluded from court. The post-Rochkind decisions only underscore those stakes.  

 

Practitioner Tips:  

Here are some resources and ideas for negotiating the treacherous waters of expert witness admissibility in Maryland in the Rochkind/Daubert era. 

 

Technical Resources:  

Some familiarity with how scientists, doctors, engineers and other experts do their work is essential to any attorney attacking -- or defending -- an expert’s admissibility in court. In its most recent decision on this topic, here is how the Maryland Supreme Court introduced the subject:  

When this Court adopted the Daubert expert testimony admissibility standard in Rochkind v. Stevenson, 471 Md. 1 (2020), we embraced a regime that prizes the reliability of an expert’s methodology over its general acceptance. We empowered trial judges to protect juries from junk science while also broadening the range of possibly admissible opinions beyond just those dominant among practitioners. We asked judges to engage with the science without playing amateur scientist, and we promised the deference appropriate to courts administering a flexible approach to analyzing the admissibility of expert testimony. 

Parkway, 485 Md. at 342, 301 A.3d at 46. 

Here are some resources for “engaging with the science,” particularly with respect to “toxic tort” causation of injury, which is one of the most prominent areas of appellate focus on expert witnesses. 

• The Federal Judicial Center’s Reference Manual on Scientific Evidence (3d ed. 2011). This is a critical resource on the desk of every federal judge and many state judges. It has chapters on medical evidence, toxicology, statistics, and other frequent topics of expert testimony. The entire manual can be downloaded at no charge from: https://www.fjc.gov/sites/default/files/2015/SciMan3D01.pdf (A fourth edition was in the works as of this writing in2024.) 

• Hill, Austin Bradford, The Environment and Disease: Association or Causation?, 58 Proc. of the Royal Soc. Med. 5, 7-12 (1965). (The classic, and short, paper on sorting out causation in toxic exposure cases.) 

• Restatement (Third) of Torts: Toxic Substances and Disease § 28 cmt. c (Am. Law Inst. 2010).  

 

Legal Research:  

The practitioner who wants to bring a Daubert challenge to an opposing expert, or who wants to help her own expert survive such a challenge, faces a daunting task that at first blush can seem overwhelming. There are literally thousands of published decisions in American courts on expert witness admissibility, all purporting to use the same Daubert criteria now blessed by the Maryland Supreme Court. So where does one start? A few suggestions:  

• Start with Md. Rule 5-702 and the ten Daubert criteria vii endorsed by the Maryland Supreme Court in Rochkind II and its later decisions discussed above.  

• Then the practitioner seeking to tame the vast body of Daubert cases would do well to read the Advisory Committee Note to the 2000 Amendment to Fed. R. Evid. 702, and the note accompanying the 2023 Amendment. 

• Once one has in hand the basic language, a good next step is to seek out caselaw with factual similarities: same expert, same expert specialty, same subject matter, same published literature. That, of course, is easier for repeating fact patterns such as the lead paint poisoning cases.  

• Look for decisions where the trial court was reversed for abusing its discretion. Nobody likes to be called out for being wrong, and trial judges are no exception. If the practitioner can legitimately argue to the trial court that the adversary’s position would invite the court to commit the same reversible error that happened in another case, that can be a powerful argument.  

• The flip side of the reversal coin is that judges like to look consistent with their past precedents. So, arguing that you are asking the court to do the same that it did in one of its previous published decisions can be persuasive. That appeared to help the winning side in Sugarman, for example. 

 

Tactical Concerns with Expert Reports and Expert Disclosures:  

Expert witness disclosures in Maryland civil courts are typically vague and conclusory. Two exceptions are the Certificate of Merit and Report that must be filed in medical malpractice cases under Md. Code Cts. & Jud. Proc. 3-2A-04(b)(1) and physical examination reports under Md. Rule 2-423. While attorneys typically and reflexively avoid disclosing more than they absolutely have to, the changing expert admissibility landscape suggests a potential change of strategy. Knowing that unprepared experts are most vulnerable to challenge, the sponsoring attorney may want to have her experts write detailed reports that eventually will be disclosed. In the interim between first draft and final draft, the “analytic gaps” which are a favorite Achilles heel for the other side to attack can instead be found and fixed. Attorneys can also help their experts find supporting literature, industry standards, and other criteria that are grist for the Daubert mill. 

Similarly, practitioners might want to reconsider the reflexive strategy many use when defending depositions: laying low and waiting for trial to clear up any confusion or misstatements in one’s expert’s testimony. Trial can be too late. Since the Maryland Supreme Court has held that a trial court can abuse its discretion merely by refusing to hold a Rochkind hearing,viii such hearings can be expected to proliferate. And the rule about “sham affidavits” can make fixing a misstatement at a deposition difficult or impossible. See Md. Rule 2-501(e). 

This applies to more than mere misstatements. For example, if an expert has been pinned down at deposition as having formed all their opinions without consulting any relevant literature, that can make it hard to supplement the record later with such literature. And an expert without objective published peer-reviewed support for their opinions is a ripe target for Daubert attack. 

In short, in the Rochkind/Daubert era, any trial lawyer trying to develop a challenge to an opposing expert, or defend against one, has to be aware at all times of the state of the factual record being developed in the discovery process. Lawyers need to monitor their experts carefully to make sure they have done their job thoroughly. It is ultimately up to the lawyer to make sure the record shows a complete and thorough discussion of the basis of the expert’s opinions. 

 

Biography: 

MAJ member Patrick Malone is the co-author of the well-known “Rules of the Road” series and the author of “The Fearless Cross-Examiner” as well as other books for trial lawyers. A former newspaper journalist, he has used his formidable writing skills to write about Maryland’s changing standards for expert witnesses in the last three editions of Maryland Tort Damages and the new edition now in press, from which this article is adapted. He is a frequent lecturer for AAJ and other national organizations on various trial-related topics.  He is a member of, among other organizations, the Inner Circle of Advocates and the International Association of Trial Lawyers.