What is the test for reasonable doubt in a criminal case?

12 As stated in Malloy v. Hogan (1964) 378 U.S. 1, 13, footnote 9, 84 S.Ct. 1489, 1496, 12 L.Ed.2d 653, quoting from an earlier case, " 'in determining whether the witness really apprehends danger in answering a question, the judge cannot permit himself to be skeptical; rather must he be acutely aware that in the deviousness of crime and its detection incrimination may be approached and achieved by obscure and unlikely lines of inquiry.' "