Abstract
Rules 405(a) and 608(a) of the Federal Rules of Evidence allow the use of testimony about a witness’s reputation to support or undermine his or her credibility in trial. This paper analyzes the evidential weight of such testimony from the point of view of social epistemology and the theory of social networks. Together they provide the necessary elements to analyze how reputation is understood in this case, and to assess the epistemic foundation of a reputational attribution. The result of the analysis will be that reputational testimony is extremely weak from an epistemological point of view, and that in many cases there are more reliable substitutes that achieve a similar purpose. The obvious fix, in my view, is to eliminate the use of reputation testimony to support or undermine the credibility, honesty, chastity or peacefulness of a witness.