Tag Archives: Expert Witness

What Is the Difference Between a Retained and Non-Retained Expert Witness?

Courts and rule-makers have categorized expert witnesses in ways that can be confusing. Placing an expert witness into the correct category can make the difference between a lawyer’s ability to use an expert at trial and a judge’s decision to exclude the expert’s testimony.

Differing terminology used by state and federal courts contributes to the confusion. Federal courts draw a distinction between retained and non-retained experts. State courts sometimes refer to a non-retained expert as a hybrid witness. In both state and federal courts, the distinction between a fact witness and an expert witness is not always clear. The procedural rules that govern disclosure and expert reports depend on classifying the witness correctly.

Fact Witnesses

Courts generally agree that a fact witness is someone who bases testimony on observation and personal knowledge. Fact witnesses testify about things they perceived. “I saw the blue car cross the centerline and collide with the red car” is fact testimony.

Fact testimony is usually given by lay witnesses, but witnesses who have expertise that does not inform their testimony can also give fact testimony. Whether the witness has specialized knowledge does not affect his or her status as a fact witness. A chemist or an economist who testifies about a car crossing a centerline and causing a collision does not become an expert witness simply because she has an advanced degree.

A jury needs no specialized knowledge to understand the testimony of a fact witness. Since fact witnesses are typically testifying about things that they perceived, fact witnesses do not usually give opinions. An exception to that rule allows lay witnesses to give rational opinions based on common experience if the opinion would help the jury understand the evidence. “He seemed angry,” an opinion based on attitude and tone of voice, is an example of a lay opinion that some courts regard as admissible if the person’s anger is relevant to the case.

Expert Witnesses

An expert witness offers opinions based on the expert’s specialized knowledge, training, or experience rather than the expert’s own perception of facts. An accident reconstruction expert who did not see the blue car cross the centerline and crash into the red car can use the location of debris, gouges in pavement, vehicle damage, and the final resting places of the two vehicles to form the opinion that the blue car crossed the centerline.

Unlike lay witnesses, experts can express opinions if the opinions would help the jury decide an issue that is relevant to the case. Every jurisdiction requires the expert to be qualified to render an opinion. Whether a qualified expert’s relevant testimony is admissible depends upon whether it satisfies the controlling standard in state or federal court. The Daubert standard applies in federal court, while states typically rely on their own version of the Daubert standard, the Frye standard, or a hybrid standard.

The line between an expert and a fact witness can be muddied when an expert discusses facts that are not within the common knowledge of lay jurors. For example, a treating physician will often explain the injuries for which an accident victim was treated. A physician who discusses the significance of a ruptured spleen will probably explain the function of an organ that most people don’t understand.

Courts typically classify treating physicians as fact witnesses, even when their explanation of the facts depends on their specialized knowledge. When a treating physician offers a prognosis, however, the physician is offering an opinion, not stating facts. How to classify a treating physician who offers opinions about the need for future healthcare is a tricky question.

Retained vs. Non-Retained Experts

In federal court, a treating physician who will offer opinions is usually classified as a non-retained expert. A non-retained expert is not hired for the specific purpose of giving expert testimony. A treating physician is hired to treat a patient. Asking that physician to testify about opinions that the physician formed in the course of treating the patient does not make the physician a retained expert because the physician was not retained for that purpose.

As one court explained, a physician is only “retained” if the physician’s testimony is not based on opinions that the physician formed while treating the patient. Thus, a treating physician who expresses an opinion about causation that is based on the physician’s observations has not been retained for the purpose of litigation. On the other hand, a physician who is retained to review medical reports and other evidence regarding a patient the physician did not treat is classified as a retained expert.

While the distinction between retained and non-retained experts usually arises when a treating physician offers an opinion, it can apply to other experts, as well. In the case linked above, the court concluded that the defendant’s former CFO, although hired and paid to offer expert opinions, was a non-retained expert because his testimony was limited to opinions that were based on observations he made while employed by the defendant.

Whether a witness is retained or non-retained is not always clear. For example, when a physician saw a patient only once, three years after an accident, assessed his injuries, and prepared a treatment plan, the absence of any ongoing treatment convinced a court that the physician was retained for the purpose of litigation. The physician offered an opinion as to whether the plaintiff’s injuries were caused in the car accident that was the subject of the litigation or in an earlier car accident. Since the physician formed his opinion by reviewing x-rays taken after the first accident, at a time when the physician was not treating the patient, the physician did not base his causation opinion on observations made in the course of treatment. He was therefore a retained expert.

Why Does the Designation Matter?

In federal court, the Rules of Civil Procedure require disclosure of all testifying experts, whether they are retained or non-retained. The rules governing disclosure of expert opinions, however, are quite different.

Rule 26 requires a retained expert to prepare a written report that includes all opinions the witness will express at trial, the reasons that underlie those opinions, and the facts or data that the witness considered in forming them. Federal courts often bar the testimony of retained experts who write insufficient reports.

Rule 26 does not require a non-retained expert to prepare a report. Instead, the lawyer who plans to call the expert as a witness must disclose the expert’s identity as well as the subject matter of the witness’ testimony and a summary of the facts and opinions to which the expert is expected to testify.

State courts that do not pattern their disclosure requirements on Rule 26 may impose different obligations. State courts sometimes refer to a non-retained expert as a hybrid witness. Whether retained and non-retained (hybrid) witnesses and their opinions must be disclosed, and whether the disclosure requirements differ, is a question lawyers can only answer by reviewing the state’s rules of civil procedure, relevant caselaw, and the court’s scheduling order.

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Ohio Supreme Court Rejects Hospital Executive as Expert Witness

The Ohio Supreme Court has ruled that a hospital executive who does not directly oversee treating physicians does not meet the requirements to testify as an expert witness in a medical malpractice suit.

Trial Court

Mark Johnson, Glenda Johnson, and Gary Johnson filed a medical malpractice suit on behalf of their brother, David Johnson. The lawsuit claimed that Dr. Anthony Abdullah was negligent in his treatment of David in 2011.

At trial, Dr. Abdullah called Dr. Ron Walls to testify as an expert witness regarding the standard of care. The Johnsons objected to Dr. Walls’ testimony, arguing that he was not involved in the active clinical practice of medicine. The trial court determined that Dr. Walls was competent to testify and he testified on Dr. Abdullah’s behalf. A jury found that Dr. Abdullah was not negligent in treating David.

Court of Appeals

The Johnsons appealed to the First District Court of Appeals. Upon review, the court addressed only the trial court’s decision to admit the testimony of Dr. Walls. The court noted that Dr. Walls was the chief operating officer of a hospital system, but that his job was “almost entirely administrative.” The court rejected Dr. Abdullah’s argument that Walls was engaged in the active clinical practice of medicine and determined that the trial court should have prevented Dr. Walls from testifying. The court reversed the trial court’s judgment and ordered a new trial.

The Supreme Court of Ohio

Dr. Abdullah appealed to the Supreme Court of Ohio. On appeal, Dr. Abdullah argued that the First District improperly reweighed Dr. Walls’ credibility. The Supreme Court disagreed. It determined that the First District did not find that Dr. Walls’ testimony was untruthful; instead, it had concluded, based on Dr. Walls’ testimony, that Dr. Abdullah had failed to establish that Dr. Walls devoted at least one-half of his professional time to the active clinical practice of medicine.

Evid.R. 601(B) provides in relevant part that a person is disqualified to testify as a witness when the court determines that the person is

(5) …giving expert testimony on the issue of liability in any medical claim, as defined in R.C. 2305.113, asserted in any civil action against a physician, podiatrist, or hospital arising out of the diagnosis, care, or treatment of any person by a physician or podiatrist, unless: . . .

(b) The person devotes at least one-half of his or her professional time to the active clinical practice in his or her field of licensure, or to its instruction in an accredited school.

In Celmer v. Rodgers, 114 Ohio St.3d 221, 2007-Ohio3697, 871 N.E.2d 557 (plurality opinion), the court explained that the purpose of the active clinical practice requirement was to prevent testimony from physicians who spend most of their time testifying as professional witnesses and lack experiential background in the area at issue in the case. The key issue in Celmer was not whether the expert’s professional activities constituted the active clinical practice of medicine; the key issue was whether a trial court may permit an expert to testify when they did not meet the requirements of Evid.R. 601 at the time the trial took place, but did meet those requirements when the trial was originally supposed to start, but then the trial was delayed by the request of the opposing party. Dr. Abdullah argued that this Celmer exception should apply here to consider the expert’s duties at the time of the alleged malpractice.

The Supreme Court declined to expand the Celmer exception. The court noted that the facts of this case are significantly different from those in Celmer. There, the court carved out a limited exception to consider the expert’s activities at the time the trial was originally scheduled to begin. Here, Dr. Abdullah asked to extend that limited exception to consider an expert’s activities long before this case was even filed.

The court noted that Dr. Walls testified that about 90 percent of his work would be considered purely executive or administrative. It determined that Dr. Abduallah failed to show that Dr. Walls was involved in the active clinical practice of medicine at the time of the trial and affirmed the ruling of the First District Court of Appeals.


Screening Experts for Conflicts of Interest and Bias

Lawyers must consider several factors when they choose an expert witness. The expert’s qualifications, reputation, and ability to communicate effectively are key considerations. The expert’s location and the lawyer’s budget are practical issues.

The potential for a conflict of interest is a factor that lawyers tend to forget. Fortunately, actual conflicts are rare. Experts are also challenged when they allegedly show a clear bias for the party that hired them. While those challenges are not usually successful, lawyers need to think about the issue of bias before retaining an expert witness.

Courts are reluctant to disqualify experts based on perceived conflicts or claims of bias. Courts tend to view those issues as going to credibility rather than admissibility. 

Even if a potential conflict does not bar an expert from testifying, lawyers want to hire credible experts. Lawyers need to consider possible challenges to an expert’s credibility based on perceived conflicts or allegations of bias. Screening experts for conflicts and bias should therefore be part of the lawyer’s assessment of potential experts.

Prior Work for an Adverse Party

Courts have the power to exclude an expert’s testimony when the expert has provided services to the opposing party. Courts exercise their power to bar the testimony of an expert who has “switched sides” when they deem it necessary “to protect the integrity of the adversary process, protect privileges that otherwise may be breached, and promote public confidence in the legal system.” 

Whether the expert will be disqualified generally depends on whether the expert received confidential information from the party that is relevant to the current lawsuit. A lawyer’s mental impression of the strengths and weaknesses of relevant claims against that lawyer’s client is an example of confidential information.

When there is a dispute about the expert’s receipt of confidential information, courts ask whether it was reasonable for the adverse party to believe that it had entered into a confidential relationship with the expert. If so, they examine the evidence to decide whether confidential information was actually shared with the expert.

Lawyers need to balance the risk of conflict against the reality that hiring an expert who was once retained by the opposing party may be advantageous. An expert’s willingness to work for both sides might be seen as evidence of the expert’s impartiality. Of course, it might also be seen as evidence that the expert is a “hired gun,” but that is a challenge facing every retained expert in every case.

When an expert has worked for the adverse party, lawyers nevertheless need to be wary. There is always a risk that the opposing party will claim that it shared confidential information with the expert. A lawyer will need to explore the expert’s relationship with the opposing party in detail and will need to assess the risk that the expert might be disqualified. If that risk is significant, the lawyer should consider whether conflict-free experts with similar qualifications are available.

The screening process should start by asking the expert whether she has any past experience with the adverse party or its lawyers. Conducting an online search for cases in which the expert testified will provide at least partial confirmation that the expert has no conflict. Still, since experts do not always testify and since it is difficult to learn of past employment as consulting experts, it is important to have a candid conversation with a potential expert witness about any contact the expert has had with an opposing party, even if the expert did not testify for that party.


Bias is often alleged by an opposing party. An expert’s consistent employment by a particular industry or group of litigants might give rise to claims of bias, but those claims are attacks on credibility that juries should resolve.

Bias may also be reflected in unreliable methodologies or a selective application of facts. Courts might disqualify experts for bias indirectly by applying the Daubert standard more strictly when there is evidence that bias may have affected the reliability of an expert’s conclusions.

Some courts have suggested that experts who base opinions on experiments or research done outside the context of litigation are more likely to produce reliable results than experts who are hired by a particular industry or group to form opinions that are specific to a lawsuit. After Daubert was remanded to the Ninth Circuit, Judge Kozinski wrote that “experts whose findings flow from existing research are less likely to have been biased toward a particular conclusion by the promise of remuneration; when an expert prepares reports and findings before being hired as a witness, that record will limit the degree to which he can tailor his testimony to serve a party’s interests.” 

That line of thought suggests that courts might be more inclined to exclude experts when they have not conducted research or expressed opinions about a particular subject before they are hired to present expert testimony. Selecting an expert who has researched a scientific question outside the context of litigation might therefore avoid claims of bias.

Still, the fact that an expert has not conducted research prior to being retained does not mean that the expert’s methodology will be tainted by bias. Courts are more likely to be troubled when, for example, an expert prepares peer-reviewed writings and fails to disclose “her potential bias because of her direct involvement in litigation in the . . . cases on which she reported.” 

Experts may also demonstrate bias when they prepare reports that contradict prior writings or testimony given in other cases if the contradictions cannot be explained by the differing facts that the expert considered. To screen against potential claims of bias, lawyers should always review an expert’s past writings and testimony to determine whether it might conflict with opinions the expert will be asked to express.

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Treating Physician Not Required to Prepare Expert Report in New Jersey

The rules of evidence in most jurisdictions require a party who wants to call an expert witness to notify the other party of the expert’s name. The rules may also require advance disclosure of the expert’s qualifications, opinions, prior testimony, and publications. In many jurisdictions, the expert must state his or her opinions in a written report that is disclosed to adverse parties prior to trial.

Jurisdictions that require an expert to prepare a report often make an exception for treating physicians who will only be asked to testify about their diagnosis and the treatment they rendered to a patient. In those cases, medical records serve as an adequate substitute for a report. In addition, treating physicians are different from retained experts, who usually expect to write a report. Treating physicians are busy with their patients and often balk at being asked to prepare a report that merely reiterates information contained in medical records.

New Jersey’s discovery rules permit a party to ask an opposing party to produce a report prepared by that party’s expert. The report must include a complete statement of the expert’s opinions and the basis for those opinions, including the facts and data upon which the expert relied. The rules make no explicit exception for treating physicians.

The New Jersey Supreme Court was recently asked whether a plaintiff who sued for disability discrimination was required to produce an expert report when she relied on the testimony of her treating physician to establish that she had a disability. The trial court excluded the treating physician’s testimony because no report had been prepared for pretrial disclosure. The supreme court concluded that the treating physician’s proposed testimony about his patient’s disability did not trigger the obligation to write a report.

Facts of the Case

Patricia Delvecchio was employed by the Township of Bridgewater as a police dispatcher. Dispatchers generally work three shifts on a rotating basis.

Delvecchio suffered from inflammatory bowel syndrome (IBS), a condition that worsened when she worked the midnight shift. Delvecchio notified the Township that she suffered from IBS and asked for an accommodation of her condition by assigning her to morning or afternoon shifts. She supported that request with notes from her gastroenterologist. The notes stated that Delvecchio’s IBS symptoms were under control when she worked regular daytime hours, but were exacerbated by assignments to the midnight shift.

After one year of assigning Delvecchio to the afternoon shift, the Township decided it was too burdensome to other dispatchers to relieve Delvecchio of all midnight shift assignments. The other dispatchers, however, cooperated in allowing Delvecchio to work daytime shifts. After additional intervention by Delvecchio’s gastroenterologist, the Township told Delvecchio that it would assign her to afternoon shifts when they were available, but insisted that she work occasional midnight shifts. It did so despite the gastroenterologist’s insistence that it was medically necessary for Delvecchio to avoid the midnight shift.

After Delvecchio repeatedly declined assignments to the midnight shift, the Township asked her to resign. When she refused, the Township made her a records clerk and reduced her pay. It later terminated her employment, citing excessive absenteeism.

Delvecchio’s Lawsuit

Delvecchio sued the Township, alleging that it violated New Jersey’s Law Against Discrimination by repeatedly assigning her to the midnight shift. Delveccio contended that IBS constitutes a disability under New Jersey law and that the Township had a duty to accommodate that condition by changing her work schedule.

Pursuant to New Jersey’s discovery rules, Delvecchio disclosed that her treating gastroenterologist would testify that Delvecchio had been diagnosed with IBS and that he wrote notes to the Township explaining that condition and the need for a work schedule change. However, Delvecchio produced no report from the gastroenterologist.

The judge ruled that New Jersey law does not allow a treating physician to testify about a plaintiff’s diagnosis or the impact of a plaintiff’s work schedule on her condition unless the physician has been designated as an expert witness. The judge allowed the gastroenterologist to testify that he was treating Delvecchio for IBS, but would not allow the doctor to explain IBS to the jury.

The court admitted the gastroenterologist’s notes into evidence but instructed the jury that they were received as evidence that Delvecchio requested an accommodation, not as evidence that she suffered from a disability. Having heard no physician’s testimony in support of the claim that Delvecchio was disabled, the jury found in favor of the Township. Delvecchio appealed.

Supreme Court’s Decision

New Jersey’s law against disability discrimination prohibits employers from discriminating against an employee with a disability “unless the nature and extent of the disability reasonably precludes the performance of the particular employment.” A disability under New Jersey law includes an infirmity that prevents “the normal exercise of any bodily function.”

A threshold question in a disability discrimination case is whether the employee is disabled. On appeal, the Township argued that evidence of a disability must be based on “a retained expert witness,” not on testimony from a treating physician.

The Township relied upon an earlier case in which the New Jersey Supreme Court held that “expert medical evidence” is required to prove the existence of a disability unless the disability is apparent. Seizing on the word “expert,” the Township argued that Delvecchio failed to designate her treating physician as an expert and failed to produce the report that New Jersey law requires experts to prepare. The Township claimed that a treating physician who is not retained as an expert cannot testify that a patient is disabled.

The supreme court disagreed. The court relied on a line of New Jersey cases that allow treating physicians “to offer medical testimony regarding the diagnosis and treatment of their patients” as a lay witness. Those cases regard treating physicians as giving testimony about medical facts, not medical opinions.

Recognizing that the attempt to distinguish a medical fact from a medical opinion creates “an artificial distinction,” the court ruled that treating physicians may always give relevant testimony about a patient’s diagnosis and treatment, even if that testimony might be characterized as an expert opinion. If the doctor’s opinion testimony extends beyond diagnosis and treatment, however, the doctor must be designated as an expert and must furnish a report before the testimony will be admissible.

The supreme court ruled that the trial court should have allowed the gastroenterologist to testify about Delvecchio’s “IBS diagnosis, the impact of IBS on [her] everyday life, and the steps that [he] recommended to alleviate [her] symptoms.” Since there was no suggestion that Delvecchio’s attorney intended to ask the doctor “to opine on global questions beyond the scope of his role as plaintiff’s treating physician,” Delvecchio was not required to designate the gastroenterologist as an expert. The court accordingly granted Delvecchio a new trial.

11th Circuit Rules Expert Testimony Based on Theory is Inadmissible

Last month, the federal 11th Circuit Court of Appeals confirmed that the lower federal trial court correctly excluded expert witness testimony due to insufficient factual support.  In a lawsuit against Fixodent denture adhesive, defendants were granted summary judgment due to the failure of plaintiff’s expert witness to link the allegedly defective product to the harm suffered.

Expert Witness Standards in Toxic Torts

In personal injury lawsuits alleging a defective product created a toxic risk, the plaintiff must be able to establish a causal link between the product and the harm suffered.  In modern litigation, this is done exclusively with expert testimony by use of scientists who either connect conclusions established by existing studies to the facts of the case or argue that a new study or method of analysis creates the necessary causal link for the plaintiff to be successful.

Regardless of whether the expert applies established scientific literature to the case or supports the application of new science to the litigation, federal judges will determine if the expert testimony is reliable and relevant by applying the test created by the Supreme Court in Daubert v Merrell Dow Pharmaceuticals.  Under Daubert, expert testimony is considered reliable if the scientific methodology is based on sound theory, was well researched, and was accurately applied the facts of the case.  Typically, judges look to established literature from peer reviewed journals to assist the determination if a particular expert is supporting his testimony with reliable science, but when the science is relatively new, judges are forced to take a close look at the methods and procedures applied by the expert witness.

In Chapman v Procter & Gamble Distributing, LLC, plaintiff’s expert witness testified to recent scientific studies that, in theory, supported the allegations that defendant’s products caused medical harm.  The 11th Circuit determined that the testifying expert had failed to connect his scientific theory to the cause of the plaintiff’s injury.

Plaintiff Expert Witness Fails Reliability Test

At issue in Chapman is whether or not Fixodent denture adhesive from P & G caused the plaintiff’s neurological disorder.  To demonstrate the necessary causal link between Fixodent and the plaintiff’s injuries, plaintiffs called an expert to argue that the excessive levels of zinc found in Fixodent created a risk for copper deficiency that would lead to neurological complications.  During his Daubert hearing, the plaintiff’s expert cited existing research, but only research that showed the connection between zinc and copper deficiency.  In terms of forming the causal link between Fixodent’s zinc levels and neurological disorders, the expert could only hypothesize based on his inference from the more general research.

The 11th Circuit was not convinced that the expert’s proposed testimony was reliable, and found that his testimony was properly excluded during trial.  Without established research to connect the specific product to the harm suffered, the plaintiff’s expert needed more than just a theory or untested hypothesis.  In regards to the particular theory advanced by the plaintiff’s expert, the Court wrote, “Taking everything together, there is enough data in the scientific literature to hypothesize causation, but not to infer it. Hypotheses are verified by testing, not by submitting them to lay juries for a vote.”

11 Circuit Disallows Expert Testimony

Affirming the trial court’s decision to exclude the expert testimony, the 11th Circuit supported its decision by writing, “Because these experts have failed to demonstrate the primary methods for proving [that] the zinc in Fixodent causes [neurological injury], their secondary methodologies, including plausible explanations, generalized case reports, hypotheses, and animal studies are insufficient proof of general causation. This latter evidence could mislead the jury by causing it to consider testimony that was insufficient by recognized primary methodologies to prove [that] using Fixodent causes [neurological injury].”

Even though the expert witness theory was based on generally accepted science the particular factual inference was not, and, as such, the plaintiff’s expert could not present his opinion during trial.  Although the exclusion of the expert witness effectively dismantled the plaintiff’s lawsuit, the 11th Circuit could not justify allowing opinion that was not based on scientific study.  The Chapman case serves as an important example of why expert witnesses must be able to support their testimony with reliable and relevant scientific study.


Florida’s Third Circuit Issues First In-Depth Treatment of Daubert

A recent decision from Florida’s Third District Court of Appeal provided an in-depth discussion on the differences between the old Frye standard of expert witness admissibility and the currently used Daubert test. In Perez v Bell South, the Court considered expert witness testimony in a personal injury claim, and clarified for future litigants how the Daubert requirements differed from the state’s previous Frye test. Although the decision applies only to Florida, analyzing the case is useful to attorneys who need to be aware how Daubert expert witness admissibility rules compare to the older standard.

Perez v Bell South Emphasizes Use of Daubert

Maria Perez filed a personal injury claim on behalf of her developmentally disabled son, Osmany, against her former employer for negligently creating a stressful work environment that resulted Osmany being born 20 weeks early. Ms. Perez alleged that Bell South caused her such significant difficulty that she suffered a placental abruption, which led to Osmany’s premature birth and subsequent developmental deficits. As part of her case, Maria called upon the medical expert testimony of Dr. Isidro Cardella, a board-certified obstetrician and gynecologist. Dr. Cardella testified that, in his opinion, Bell South’s refusal to allow Ms. Perez frequent bathroom breaks or limit her working hours to 40 created such stress on her body that she suffered the placental abruption.

The trial court dismissed Dr. Cardella’s expert testimony and Ms. Perez’s case because it was based solely on his opinion as a medical expert. Applying the Frye test, the trial judge determined that an opinion not supported by medical evidence or research is inadmissible.  Ms. Perez appealed, arguing that “pure opinion” testimony does not fall within the guidelines of Frye. On appeal, Florida’s Third District Court correctly made the dispute over Dr. Cardella’s testimony moot by analyzing under the state’s newly adopted Daubert standard – clarifying for attorneys, and judges, how expert witness testimony, including opinion, is to be evaluated in the future.

Daubert Test v Frye Test

Created by the 1993 Supreme Court decision in Daubert v Merrell Dow Pharmaceuticals, the Daubert standard sets forth an evidentiary rule that determines whether or not expert witnesses are permitted to testify at trial. Over the last two decades, all federal jurisdictions and over half of the states have implemented the Daubert test, however, a number of states, including California and Illinois, have yet to make the switch. Relevant to the Perez case, Florida’s legislature enacted a law that made the Daubert standard the official state rule as of July 2013.

Prior to Daubert, courts analyzed expert witness testimony under a test established in the 1923 case, Frye v United States. The Frye test simply required courts to determine if an expert witnesses testimony was based on scientific methods that are “sufficiently established” in, and generally accepted by, the scientific community to which the expert belongs. As the Perez Court pointed out, the Daubert standard, as adopted by Florida’s legislature in 2013, requires additional analysis. Ensuring that an expert’s methods are accepted and established by the greater scientific community is one of many factors that a court must consider under Daubert, as now codified in Florida’s rules of evidence.

Florida courts must consider a number of factors to ensure expert witness testimony is scientifically reliable – most notably determined by analyzing an expert’s methodology and scientific knowledge. In addition to an expert’s approach being generally accepted, courts must also consider the level of peer review it has been subjected to, the error rate that can influence his results, and the existence of professional standards that govern the operation of an expert’s investigation. The Daubert standard requires courts to look at a variety of factors, and the Perez case noted that a simple Frye evaluation of expert witness testimony is no longer sufficient in Florida.

Understanding the Daubert Standard

Reviewing Dr. Cardella’s testimony through a Daubert lens, Florida’s Third District Court of Appeal arrived at the same conclusion – his testimony was inadmissible. The pathway to the correct decision is important, however, because, as Ms. Perez’s attorneys pointed out, a Frye analysis is not sufficient to evaluate a pure opinion testimony. Using the Daubert test, which applies to any expert witness testimony, Florida courts can determine the admissibility of an expert’s analysis of facts and his opinion of the case. Under Daubert, Dr. Cardella’s testimony still fell short because he did not back his conclusions with scientifically reliable support.

Attorneys who intend to use expert witnesses must understand the proper application of the Daubert standard and be prepared to use an expert who can provide reliable, scientific knowledge to support testimony. With limited exception, the Daubert standard controls expert witness admissibility, and, as Florida’s Perez v Bell South demonstrates, Daubert is more comprehensive and thorough than the once widely-used Frye test.