Expert witness testimony: a trial judge’s perspective


This article discusses the use of expert, scientific testimony in Judge Weinstein’s courtroom cases that involved Agent Orange, silicone breast implants, repetitive stress injuries, diethylstilbestrol (DES), and asbestos. The author summarizes the evidentiary standards for admitting expert, scientific testimony, and discusses some of the unique ethical and logistical issues presented by such evidence. Advice is offered for prospective expert witnesses. Possible solutions to the problems the legal and scientific communities face in balancing society’s need for expert evidence and its limitations are addressed.


Expert witness testimony: A trial judge’s perspective, NCBI PubMed PMID: 10196416,

Neurologic Clinics, Volume 17, Issue 2, 1, Pages 355–362, May 1999.

Expert witnesses are critical to the court’s work.

Typical cases on my own docket—silicone breast implants, repetitive stress injuries, diethylstilbestrol (DES), tobacco, and asbestos—are but a few of the litigations rich in scientific and abstruse medical issues.

Although modern jurors are perceptive, devoted, and thoughtful,  they, like the judges, are laypersons and have only the most general notion of science as it relates to particular cases. Expert witnesses are needed to analyze complex scientific issues in the light of the evidence and to present their scientifically based opinions in an understandable way.

Among many kinds of experts that have appeared before me, I have a particular fondness for neurologists. Their testimony is understandable, generally reliable, and usually crisp and to the point. Their opinions are also usually backed by objective tests. In a series of the repetitive stress injury trials alleging injury to the upper extremities and spinal column caused by use of computer keyboards, the neurologists for both sides were impressive and forthright. Though they disagreed on some matters, they were credible, well informed, and articulate. They had, of course, been chosen for their outstanding credentials and were, therefore, perhaps, not a fair sampling of the profession.

Jack B. Weinstein

Click to purchase the full paper.

More DES DiEthylStilbestrol Resources

Have your say! Share your views