Self-Incrimination and the Epistemology of Testimony

Abstract

The United States Supreme Court's limitation of the privilege against self-incrimination to evidence of a testimonial nature has been controversial. The doctrinal reliance on a distinction between physical and testimonial evidence has proven difficult to apply in practice, and it has been criticized as being descriptively inaccurate, analytically incoherent, and normatively indefensible. This article offers a defense of the distinction on epistemological grounds. The philosophical focus on testimony as a source of knowledge provides some insight into what makes testimony distinct as an epistemic source. These considerations are used to provide a coherent and principled way to distinguish what evidence to treat as testimonial for Fifth Amendment purposes: any evidence that requires a fact-finder to rely on the epistemic authority of the defendant. This principle is then used to justify a testimonial privilege in light of the presumption of innocence and to clarify doctrine.