Federal Rule of Evidence 702

Robert Joiner began work as an electrician in the Water & Light Department of Thomasville, Georgia, in 1973. This job required him to work with and around the City’s electrical transformers, which used a mineral-oil-based dielectric fluid as a coolant. Joiner often had to stick his hands and arms into the fluid to make repairs. The fluid would sometimes splash onto him, occasionally getting into his eyes and mouth. In 1983 the City discovered that the fluid in some of the transformers was contaminated with polychlorinated biphenyls. Joiner was diagnosed with small-cell lung cancer in 1991. He sued petitioners in Georgia state court the following year. Petitioner Monsanto manufactured PCB’s from 1935 to 1977. Petitioners General Electric and Westinghouse Electric manufactured transformers and dielectric fluid. In his complaint Joiner linked his development of cancer to his exposure to PCB’s and their derivatives, polychlorinated dibenzofurans and polychlorinated dibenzodioxins. Joiner had been a smoker for approximately eight years. His parents had both been smokers, and there was a history of lung cancer in his family. Petitioners removed the case to federal court. Once there, they moved for summary judgment. Joiner responded that there were numerous disputed factual issues that required resolution by a jury. He relied largely on the testimony of expert witnesses. In depositions, his experts had testified that PCB’s alone can promote cancer and that furans and dioxins can also promote cancer. They opined that since Joiner had been exposed to PCB’s, furans, and dioxins, such exposure was likely responsible for Joiner’s cancer. The District Court ruled that there was a genuine issue of material fact as to whether Joiner had been exposed to PCB’s. But it nevertheless granted summary judgment for petitioners because there was no genuine issue as to whether Joiner had been exposed to furans and dioxins. The testimony of Joiner’s experts had failed to show that there was a link between exposure to PCB’s and small-cell lung cancer. The court believed that the testimony of respondent’s experts to the contrary did not rise above subjective belief or unsupported speculation. The Court of Appeals for the Eleventh Circuit reversed. It held that because the Federal Rules of Evidence governing expert testimony display a preference for admissibility, it applied a particularly stringent standard of review to the trial judge’s exclusion of expert testimony. The Supreme Court granted petitioners’ petition for a writ of certiorari.