Expert Testimony (Litigator Series)

THIS CASEBOOK contains a selection of 115 U. S. Court of Appeals decisions that analyze and discuss issues surrounding expert testimony. The selection of decisions spans from 2010 to the date of publication.

Federal Rule of Evidence 702 governs the admissibility of expert evidence. Expert testimony under Rule 702 is admissible if it "rests on a reliable foundation and is relevant." Westberry v. Gislaved Gummi AB, 178 F.3d 257, 260 (4th Cir. 1999) (quoting Kumho Tire Co. v. Carmichael, 526 U.S. 137, 141 (1999)). In determining reliability, a district court exercises a special gatekeeping obligation. See Kumho, 526 U.S. at 147. It possesses "broad latitude" to take into account any "factors bearing on validity that the court finds to be useful." Westberry, 178 F.3d at 261. The scope of the court's gatekeeping inquiry will depend upon the particular expert testimony and facts of the case. See Kumho, 526 U.S. at 150. Equal Employment Opportunity Commission v. Freeman, (4th Cir. 2015).

The opinion of a qualified expert witness is admissible if (1) it is based on sufficient facts or data, (2) it is the product of reliable principles and methods, and (3) the expert has reliably applied the principles and methods to the facts of the case. Fed. R. Evid. 702. The expert's scientific, technical, or other specialized knowledge must also "help the trier of fact to understand the evidence or determine a fact in issue." Id. The district court is thus vested with a gatekeeping function, ensuring that "any and all scientific testimony or evidence admitted is not only relevant, but reliable." Daubert, 509 U.S. at 589. The Supreme Court identified in Daubert a number of factors that might assist the district court in determining the admissibility of expert evidence. Id. at 593-94. The Court instructed district courts to focus on "principles and methodology, not on the conclusions that they generate." Id. at 595. Expert evidence may be excluded if "there is simply too great an analytical gap between the data and the opinion proffered." Gen. Elec. Co. v. Joiner, 522 U.S. 136, 146 (1997). Union Pacific Railroad Company v. Progress Rail Services Corporation, (8th Cir. 2015).

[Th]e Supreme Court made clear in Daubert v. Merrell Dow Pharmaceuticals, Inc., 509 U.S. 579, 113 S. Ct. 2786 (1993), Rule 702 requires district courts to serve an important gatekeeping function concerning the admissibility of expert scientific evidence and technical expert evidence. Frazier, 387 F.3d at 1260. Thus, district courts must engage in a three-part inquiry in determining the admissibility of expert testimony under Rule 702, considering whether:

(1) the expert is qualified to testify competently regarding the matters he intends to address; (2) the methodology by which the expert reaches his conclusions is sufficiently reliable as determined by the sort of inquiry mandated in Daubert; and (3) the testimony assists the trier of fact, through the application of scientific, technical, or specialized expertise, to understand the evidence or to determine a fact in issue.

Id. (quoting City of Tuscaloosa v. Harcros Chems., Inc., 158 F.3d 548, 562 (11th Cir. 1998)). US v. Holt, (11th Cir. 2015)

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