Section 607 Of Article 1. General From California Evidence Code >> Division 5. >> Chapter 3. >> Article 1.

. When a presumption affecting the burden of proof operates in a criminal action to establish presumptively any fact that is essential to the defendant's guilt, the presumption operates only if the facts that give rise to the presumption have been found or otherwise established beyond a reasonable doubt and, in such case, the defendant need only raise a reasonable doubt as to the existence of the presumed fact.