Taking A Science Expert Deposition To Set Up A Daubert Motion

In any deposition, counsel wants to get the jury-friendly admission from a plaintiff's medical expert that will be the key to a defense verdict—whether it is a causation admission that something other than your client's product could have caused the injury or a credibility admission that casts doubt on the expert's testimony. In some cases, however, there may be an opportunity to get something more than the admissions that will sway a jury. There may be an opportunity to exclude the expert from testifying at all or to substantially limit the scope of the expert's testimony. Here, we discuss strategies and techniques for deposing an expert to set up a Daubert motion aimed at excluding plaintiff's expert from testifying at trial.

Federal Rule of Evidence 702, which sets forth the requirements for the admissibility of expert testimony, provides:

If scientific, technical, or other specialized knowledge will assist the trier of fact to understand the evidence or to determine a fact in issue, a witness qualified as an expert by knowledge, skill, experience, training, or education, may testify thereto in the form of an opinion or otherwise, if (1) the testimony is based upon sufficient facts or data, (2) the testimony is the product of reliable principles and methods, and (3) the witness has applied the principles and methods reliably to the facts of the case.

Thus, the primary requirements for an expert to offer opinion testimony at trial are: (1) the expert possesses knowledge beyond that of a lay person that will assist the jury; (2) the expert must be qualified; and (3) the methodology must be reliable and must fit the case. An expert deposition should probe each of these requirements, particularly the reliability of the experts' methodology.

In many ways, a Daubert challenge is like a high-school math test. You may get the right answer to the question, but if you don't show that you got the answer the right way, you won't pass the test. The same applies here. A Daubert challenge does not go to the expert's conclusion, but rather the methodology. It bears repeating that a Daubert motion is not fundamentally about whether the plaintiffs' expert is right or wrong because that is a jury question. Thus, a common rebuttal to any Daubert motion is that defendants are merely challenging the conclusions of the expert, not the expert's actual methodology. The proponent of the expert will portray the issue as a legitimate scientific debate where reasonable experts merely disagree. In order to prevail on a Daubert motion, the aim is not to show that the expert reached a conclusion that is wrong, but that the experts used flawed methods to reach it.

Is the Expert Qualified?

Although it is rare that a party will put forth an expert that is simply unqualified to bring some special knowledge or skill beyond that of a layperson, setting up an appropriate attack on qualifications as an initial matter can ultimately alert the court to any limitations or biases that may raise skepticism about the expert's methods. Further, even if the attack on an expert's qualifications does not play directly into the Daubert challenge, it may provide useful material for cross-examination at trial. Therefore, when preparing for any expert deposition, counsel should start by...