Defending the Accuracy of Expert Testimony

Defending the Accuracy of Expert Testimony

Your Expert Testimony May Sound Impressive, But Can You Prove It?

When much of your case rests on your expert's testimony, the ever-looming threat of a Daubert motion is unnerving, to say the least. Overcoming a Daubert challenge will require intensive strategizing beforehand, including an extensive review of earlier cases wherein a Daubert motion was raised. Fed. R. Evid. 702 boils down to a three-pronged test when it comes to a Daubert analysis:

  • Qualifications: The proffered witness must be an expert qualified “by knowledge, skill, experience, training, or education…”

  • Relevance: The expert’s scientific, technical, or specialized knowledge must help the trier of fact.

  • Reliability: The testimony must be based on facts and sound “methods and principles.”

The following strategies are vital for passing this test.

Highlight Credentials

The first step, arguably the easiest, to validating your expert witness is attaching a detailed and current curriculum vitae (CV) that outlines his/her educational background, training, experience, certification, and publications. Include all published, peer-reviewed literature that specifically addresses the subject(s) on which your expert will testify. Be prepared to emphasize that "the level of the expert's expertise goes to credibility and weight, not admissibility" (Kannankeril v. Terminix Intern., Inc., 128 F.3d 802 at 809).

Keep the Testimony Focused on the Case

Rule 702 (a) stipulates that “The expert’s scientific, technical, or other specialized knowledge will help the trier of fact to understand the evidence or to determine a fact in issue.” [italics added] Many expert witnesses are relatively new to the legal process, and they may out of habit want to offer wide-ranging insights on their topic of expertise. If the expert is your witness, you may need to coach him or her to “color within the lines” to avoid allowing the testimony to drift into irrelevant subject areas. Conversely, if an opposing counsel’s expert goes too far afield, be vigilant and insist that he or she stays on topic.Emphasize Reliability

Arguing that your expert is reliable is probably the toughest challenge. Beyond credentials, Daubert outlines five non-exclusive factors that can be used to demonstrate that your expert's opinion is reliable. These factors include reproducibility through independent testing. For example, in Lock Realty Corp v. U.S. Health, the court excluded the plaintiff's expert testimony in a breach of contract claim because her opinion was based on just two emails between the parties and a Medicaid valuation of fair market value. The court indicated that the lack of relevant source data made it difficult for another expert to replicate the analysis; thus, her method could not be properly tested.

Peer-reviewed literature is another important factor in helping to bolster your expert's credibility on the subject. The lack thereof won't necessarily disqualify your expert's testimony—as seen in the case of Primiano v. Cook, 598 F.3d 558 (9th Cir. 2010). Some circumstances, as this case illustrates, are so extraordinary that peer-reviewed literature addressing them can be difficult to come by. However, expert peer review on the specific case in question can easily compensate for a lack of previously existing peer-reviewed literature. 

The Daubert standard ensures a holistic evaluation of expert testimony. The trial court has great latitude in inquiring about the reliability of an expert opinion. Use of peer reviewed literature is an effective indicator, but not a necessary one. JuriLytics, for example, could validate an expert’s opinions by coordinating a peer review process to determine an expert’s reliability regardless of whether the expert in question has previously-published work on the subject or not.

Comments (1)

  • Mary Beth Hauptle

    The kink in the wheel is the use of unvalidated, unreliable, unscientific testimony in prior cases setting precedent by self-proclaimed experts in the field; sheltered by a dubious "self-certifying" board. The ABFO, for example. Being "board-certified" confers no assurance of consistency of opinion on what is, or is not, a bite mark. I'm thinking about 24 cases decided upon by erroneous bite mark evidence, which resulted in wrongful conviction, and imprisonment; convictions overturned by DNA testing.

    3/5/2016, 1:21:45 AM

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