Daubert analysis

In 2001, three current or former female employees of Wal-Mart Stores, Inc.—Betty Dukes, Christine Kwapnoski, and Edith Arana—filed a lawsuit in the Northern District of California alleging that the company had discriminated against them and other women in pay and promotions. Wal-Mart, the nation’s largest private employer with approximately 3,400 stores across the country and more than one million employees, delegated pay and promotion decisions to local store managers who exercised broad discretion in a largely subjective manner. The plaintiffs claimed that this discretion was exercised disproportionately in favor of men, resulting in lower pay and fewer promotions for female employees. They sought to represent a class of approximately 1.5 million current and former female employees who had worked at any Wal-Mart domestic retail store since December 26, 1998. To support their motion for class certification, the plaintiffs presented statistical evidence from experts Dr. Richard Drogin and Dr. Marc Bendick showing pay and promotion disparities between men and women, anecdotal evidence consisting of about 120 affidavits from female employees describing discriminatory experiences at only 235 of the company's 3,400 stores, and the testimony of sociologist Dr. William Bielby who analyzed Wal-Mart’s corporate culture. Betty Dukes began working at a Pittsburg, California store in 1994 as a cashier and was later promoted to customer service manager before being demoted; she alleged retaliation and that male greeters were paid more. Christine Kwapnoski worked at Sam’s Club stores and claimed a male manager yelled at female employees and told her to “doll up.” Edith Arana worked at a Duarte, California store from 1995 to 2001. She was denied opportunities for management training despite repeated requests. The District Court certified the class under Federal Rule of Civil Procedure 23(b)(2), finding that the plaintiffs had presented significant evidence of a company-wide pattern of discrimination. The Court of Appeals for the Ninth Circuit, sitting en banc, substantially affirmed the certification order. The Supreme Court granted certiorari to review whether the class certification was consistent with Rule 23(a) and (b)(2).

In March 1992, Edward G. Scheffer, an airman stationed at March Air Force Base in California, volunteered to work as an informant on drug investigations for the Air Force Office of Special Investigations. His OSI supervisors advised him that they would ask him to submit to drug testing and polygraph examinations from time to time during his undercover work. In early April, one of the OSI agents supervising Scheffer requested that he submit to a urine test. Shortly after providing the urine sample, but before the results were known, Scheffer agreed to take a polygraph test administered by an OSI examiner, who concluded that the test indicated no deception when Scheffer denied using drugs since joining the Air Force. On April 30, Scheffer unaccountably failed to appear for work and could not be found on the base. He remained absent without leave until May 13, when an Iowa state patrolman arrested him following a routine traffic stop and held him for return to the base. OSI agents later learned that Scheffer's urinalysis revealed the presence of methamphetamine. Scheffer was tried by general court-martial on charges of using methamphetamine, failing to go to his appointed place of duty, wrongfully absenting himself from the base for 13 days, and, with respect to an unrelated matter, uttering 17 insufficient funds checks. At trial Scheffer testified on his own behalf, relying upon an innocent ingestion theory and denying that he had knowingly used drugs while working for OSI. On cross-examination the prosecution attempted to impeach him with inconsistencies between his trial testimony and earlier statements he had made to OSI. Scheffer sought to introduce the polygraph evidence in support of his testimony that he did not knowingly use drugs, but the military judge denied the motion and excluded the evidence pursuant to Military Rule of Evidence 707. Scheffer was convicted on all counts and sentenced to a bad-conduct discharge, confinement for 30 months, total forfeiture of all pay and allowances, and reduction to the lowest enlisted grade. The Air Force Court of Criminal Appeals affirmed in all material respects. By a 3-to-2 vote the United States Court of Appeals for the Armed Forces reversed. The Supreme Court granted certiorari.

A deputy sheriff stopped Reginald Harris's rental car for weaving on the highway. Harris consented to a search that uncovered 19 kilograms of cocaine in two suitcases in the trunk, leading to his immediate arrest. Shortly after the arrest, DEA Special Agent Donald Walton interviewed Harris by telephone. Harris stated that he obtained the cocaine from an unidentified Cuban in Fort Lauderdale, that the cocaine belonged to petitioner Fredel Williamson, and that it was to be delivered to a particular dumpster that night. Physical evidence also connected Williamson to the car: the luggage bore the initials of Williamson's sister, Williamson was listed as an additional driver on the rental agreement, and an envelope addressed to Williamson along with a receipt bearing his girlfriend's address were found in the glove compartment. Several hours later, Agent Walton spoke with Harris in person. Harris explained that he had rented the car a few days earlier, driven it to Fort Lauderdale to meet Williamson, and received the cocaine from a Cuban acquaintance of Williamson along with a note instructing him on the delivery. Harris repeated that he was to leave the drugs in a dumpster, return to his car, and depart without waiting. When Agent Walton prepared to arrange a controlled delivery, Harris admitted he had lied about the Cuban, the note, and the dumpster. He stated instead that he was transporting the cocaine to Atlanta for Williamson, who was traveling ahead in another rental car, and that Williamson had driven past the stop and seen the police searching the trunk. Harris explained he had lied out of fear of Williamson and refused to have his statement recorded or to sign a written version, though Walton promised to report any cooperation to the prosecutor. At Williamson's trial on charges of possessing cocaine with intent to distribute, conspiring to possess cocaine with intent to distribute, and traveling interstate to promote the distribution of cocaine, Harris refused to testify despite receiving use immunity and being held in contempt. The District Court admitted Agent Walton's testimony about Harris's statements under Federal Rule of Evidence 804(b)(3), finding them against Harris's penal interest, Harris unavailable, and sufficient corroboration present. The Court of Appeals for the Eleventh Circuit affirmed the conviction without opinion, and the Supreme Court granted certiorari.