"Five researchers from Columbia University, the Baylor College of Medicine, the Albert Einstein College of Medicine, and other prominent institutions had submitted reports arguing that acetaminophen’s links to autism and ADHD are real. They’d been paid by lawyers for the plaintiffs, who included parents alleging their children had been harmed by the painkiller. But, “These scientists are not professional witnesses,” plaintiffs’ attorney Ashley Keller told the court as he displayed their faces on a screen. “They care deeply about public health.”
The opposing side had its own scientists—an additional half-dozen of them, with equally illustrious academic credentials, paid by companies that make or sell acetaminophen.
U.S. District Judge Denise Cote played the role of all-powerful peer reviewer. She had to decide whether the plaintiffs’ expert opinions were based on “reliable principles and methods,” and thus admissible in court. It was a pivotal issue; if Cote ruled against admitting the experts for the plaintiffs, their case could collapse. As the hearing closed, Cote promised a prompt decision.
The academic firepower brandished in that 7 December 2023 federal court hearing was unusually impressive. But science is a regular guest in U.S. courtrooms. Hydrologists and toxicologists testify routinely about the sources and consequences of groundwater contamination. Structural engineers assign blame for collapsed buildings. In criminal cases, scientists explain DNA evidence, or the limitations of prosecutorial tools such as fingerprints or eyewitness identification.
Lawyers often hire technical specialists from consulting firms who have made a career out of serving as an expert witness. But when the stakes are high, and the science is crucial—as in the acetaminophen case—they often prefer to bring in university professors. It’s an unusual, and often taxing, role for most academics, and Science set out to learn what it is like, interviewing both scientists and the lawyers who hire and question them.
Academics who have served as expert witnesses say the experience comes with a complicated mix of rewards and risks. The work sometimes involves depositions and trials that can last days, weeks, or months. Cross-examinations can be hostile and challenging."
