A sociologist and criminologist opposed to the death penalty, the author had to present data obtained in research on the relationship between race and sentence in States where rape was a capital offense. Not only did the restrictions of court-directed language affect the kinds of precise, valid statements a researcher could make, but the author had to confront a fundamental, ethical question. Does a social scientist have an obligation to publish or refrain from publishing material that might damage the political-social position he feels as a citizen? Other problems facing the social scientist-expert witness explored include style of testimony, interpretation of findings, and vulnerability of scientific inquiry. The author also describes his experiences as an expert witness on black versus white arrest rates in an employment discrimination case. 2 footnotes.