The materials in this chapter concern two procedural hurdles that defendants may confront at trial. We will first discuss presumptions, which are far less prevalent in criminal practice now than several decades ago. Our attention for the remainder of the chapter, and indeed of the book, will be almost exclusively on the place of “defenses” in the criminal law. These are unsettled areas of the law. The notion that defenses can be categorized as either excuse or justification, which is the primary topic in this chapter, is new to Anglo-Saxon jurisprudence. The distinction, however, is hardly academic; it has many practical, as well as theoretical, implications.
This chapter investigates what we mean when we say that D has a “defense.” Does a defense relate to an element of the crime? If so, how? May the state require the defendant to carry the burden of proof on a “defense”? And by what procedural mechanisms or labels may it do that? Chapters 16 and 17 investigate specific kinds of defensive claims. Chapter 16 looks at many claims that may be classified as “justifications,” while Chapter 17 considers claims of “excuse.” Throughout those two chapters, however, we will refer back to the issues raised in this chapter. They are all of the same cloth.
One procedural device by which the state may attempt to shift the burden of proof (or production) to the defendant is a presumption. Civil law employs many kinds of presumptions. Some are “conclusive”—no matter what proof the opposing party wishes to present, the law will “presume” the fact against her. For example, the common law presumed that a child born to a married woman was the child of the husband. No contrary facts, such as that the husband was infertile or that he had been absent for one year (or even ten), were admissible to rebut the presumption. This was a policy decision. The courts did not wish to inquire into the private lives of married couples, nor did they wish unnecessarily to label children as “illegitimate.”
Other presumptions are established for different reasons. Some are based on common sense and experience. For example, the law presumes that a letter dropped in a government mailbox was delivered because, in the vast majority of cases, when a letter is sent, it actually arrives. By applying this “presumption,” we move the litigation forward. Since, in our common experience, most letters are delivered, once the plaintiff has shown that he put the letter in a mailbox, the defendant must show that our common experience should not be applied to the specific facts of this specific case. It would be needlessly time-consuming to require the plaintiff to show that the letter was delivered. On the other hand, if the defendant wishes to demonstrate that the letter did not arrive, he may be allowed to rebut the presumption. He might, for example, show that the mailbox into which the letter was placed was thereafter robbed, or that, as a normal business matter, the defendant records every incoming piece of mail and that there is no such recording of the plaintiff’s letter.