Disagreements regarding proper application of section 2113(d) of the Bank Robbery Act focus on two questions: whether an unarmed accomplice who plans or participates in a bank robbery can be presumed to have known that the principals would endanger lives during the robbery and whether a jury may presume from evidence that a potentially dangerous weapon or device displayed during a robbery is capable of inflicting serious injury and whether such a presumption is rebuttable by evidence that the weapon was inoperable. The Supreme Court has struggled for decades to define due process requirements imposed on the use of presumptions through the cases of Winship, Mullaney v. Wilbur, Patterson v. New York, and Sandstorm v. Montana, pronouncing and reaffirming the principle that the prosecution must bear the heavy burden of proving beyond a reasonable doubt every essential element of a crime. The obvious tension between this principle and the holding of Ulster County Court v. Allen that permissive inferences need only meet the standard that a presumed fact flows more-likely-than-not from a proven fact is manifested in various cases arising under the Federal Bank Robbery Act. Courts have allowed that the use of a gun suggests the gun is loaded and that aiding the robbery suggests knowledge that a dangerous weapon would be used. These decisions denigrate a fundamental principle of statutory construction and contradict the reasonable doubt standard. The article includes 169 footnotes.