Use of social scientific and empirical assessment as a crucial element in constitutional decision-making makes criminal procedure decisions more transparent. More transparent describes adjudication that expressly and openly discusses the normative judgments at the core of constitutional criminal procedure. Such judgments are more transparent in that they expressly articulate the grounds for factual assertions and, as a result, more clearly reflect the interpretive choices involved in criminal procedure decision-making. Increased attention to empirical evidence may not guarantee right answers in criminal procedure cases, but use of empirical evidence will produce a clearer picture of the existing constitutional landscape and spotlight the normative judgments at the heart of criminal procedure cases. The article concludes with the hope that more infusion of social science will highlight potential biases, will inspire judges to make more narrow, limited, and provisional decisions and, at a minimum, hold judges more accountable. Notes, tables