In law, we never prove anything to 100% certainty. For factual propositions, the proponent has the burden of proving them to the satisfaction of a standard: a preponderance of the evidence at the low end; clear and convincing evidence in the middle; proof beyond a reasonable doubt at the high end. The standards are often explicit. Yet, for legal propositions, standards are often implicit or lacking altogether. This Article argues that, to decide legal issues, courts may look to similar burdens of proof that they use to decide factual issues. They should do so informally, using burdens of proof just as rules of thumb to guide their interpretation and application of law. Whereas the standard for statutory law should be at least a preponderance of the evidence, the standard for constitutional law ought to be higher—clear and convincing evidence—because judicial decisions on the meaning and applicability of constitutional (as opposed to statutory) law are harder to change by normal democratic means. But the standard should not be so high that courts cannot say what constitutional law means or how it applies in the face of any reasonable doubt, even if the evidence weighs heavily in one direction. The evidence may include textual, historical, and logical clues. To illustrate how this theory may work, this Article looks at an example related to the Sixth Amendment Confrontation Clause, which constitutionally guarantees the right of criminal defendants to be confronted with the “witnesses” against them. The Article concludes that the Clause’s application to forensic experts, as “witnesses,” simply is not warranted by clear and convincing evidence. Courts should not have accepted that application in

Enrique Schaerer*

* J.D., 2008, Yale Law School; B.A., B.B.A., 2005, University of Notre Dame. Partner and Shareholder, Maupin, Cox & LeGoy. Former Fellow in Law, U.C.L.A. School of Law. Former Law Clerk to Hon. Carlos T. Bea, U.S. Court of Appeals for the Ninth Circuit, and Hon. James V. Selna, U.S. District Court for the Central District of California. For helpful input, I thank Andrew Blair-Stanek, Anthony Deardurff, Kristine Kalanges, Brian Lee, Lee Otis, Joseph Plater, Richard Re, Eugene Volokh, and Lincoln Wolfe.