Mistakes of Criminal Law Research Paper

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The criminal law exists to prevent various kinds of harm, and those who violate its prohibitions are usually culpable because conduct that risks or causes harm is generally culpable conduct. For various reasons, however, a wedge can be driven between culpability and the causing or risking of harm. One can cause or risk harm without being culpable, and one can be culpable without causing or risking harm.

Mistakes illustrate the gap between culpability and harm. One can cause harm because one mistakenly believes her conduct is harmless. Conversely, she can mistakenly believe her conduct is harmful and thereby act culpably but not harmfully. Put succinctly, mistakes can exculpate one who causes or risks harm and can inculpate one who acts harmlessly or even beneficially. This research paper will deal exclusively with exculpatory mistakes. Inculpatory mistakes are usually dealt with under the topic of Attempted Crimes, specifically under the doctrines of Factual Impossibility and Legal Impossibility.

The Traditional Approach

Traditionally, exculpatory mistakes have been treated in Anglo-American law as follows. If one engages in the prohibited conduct by mistake (as to what conduct one is engaging in), or causes the harm the law seeks to avoid by mistake (as to the riskiness of one’s conduct), then, unless the crime requires the specific intent to engage in the particular conduct or cause the harm—in which case a mistake entails the absence of such an intent and therefore the absence of the crime—one is excused from criminal liability if, and only if, one’s mistake is ‘‘reasonable.’’ On the other hand, if one makes no mistake about what one is doing, or one’s mistake is ‘‘unreasonable’’ (and no specific intent is required), then one is guilty of a criminal violation even if one does not realize the conduct is illegal, and even if that mistake is a reasonable one. In other words, although reasonable mistakes of fact will exculpate, mistakes over the existence or meaning of the criminal law itself, no matter how reasonable, will not. This last point is reflected in the aphorism ‘‘Ignorance of the law is no excuse.’’

The traditional approach is quite confusing and misleading in several respects. First, it treats a claim of mistake as an excuse for having committed a crime rather than as a denial that any crime has occurred. Secondly, and relatedly, it places the burden of proving the mistake on the defendant when it is the prosecution that must prove the crime. Third, and contrary to the popular aphorism, mistakes of law frequently exculpate and cannot be neatly distinguished from mistakes of fact.

To illustrate the first and second confusions in the traditional approach, consider Jane, who fires a fatal bullet at Joe and is charged with criminal homicide. Jane claims that she was hunting and believed Joe was a deer. On the traditional approach, Jane is guilty of homicide unless she proves that she made a reasonable mistake.

But suppose the criminal homicide she is charged with is ‘‘intentional homicide,’’ which requires that she kill a human being knowingly or purposefully. Theoretically, the prosecution must prove that she knew or intended to kill a human being. This requirement is completely at odds with the requirement that Jane prove that she made a reasonable mistake regarding what she was shooting. If she made the mistake she claims, then whether or not her mistake was ‘‘reasonable,’’ she did not commit the crime of intentional homicide in the first place and should not need to offer a defense to such a crime. Rather, the prosecution should have to prove— beyond a reasonable doubt—that Jane was not mistaken. For it is the prosecution’s burden to prove the elements of the crime, one of which is an intent to kill. And Jane’s claim of mistake is nothing more than a denial of that intent.

With respect to the third criticism of the traditional approach, which criticism is directed at the maxim that ignorance of the law is no excuse, consider the case of Regina v. Smith (David), 2 Q.B. 354 (1974). The defendant there was charged with intentionally destroying the property of another. He had torn off some paneling that he himself had earlier affixed to the walls of his apartment. When he tore it off the walls, he believed he had a legal right to do so because he had installed it. He was unaware that the law of property makes items affixed by a tenant to a landlord’s property the legal property of the landlord rather than the tenant. Assuming, however, that the criminal statute required knowledge that the property the defendant was destroying belonged to another, the defendant’s ignorance of the law would render him not guilty of the crime, even under the traditional approach, and the court so held.

Moreover, the traditional approach to ignorance of law is tempered in the United States by various constitutional doctrines prohibiting ex post facto punishment and punishment under vague laws. And in one instance, Lambert v. California, 355 U.S. 225 (1957), involving a law requiring a specific action that almost no one would anticipate, the Supreme Court held punishment of one who was unaware of the requirement to be unconstitutional.

The Elements Approach

Due to the influence of the Model Penal Code (MPC), the traditional approach to exculpatory mistakes has been largely replaced by the ‘‘elements approach’’: a mistake exculpates if and only if it negates the mens rea (criminal mental state) that the legislature has required for the particular element of the crime. For example, if the legislature requires knowledge of X in its definition of the crime, any belief that X does not exist—any mistake, legal or factual, reasonable or not—will negate the crime, since belief in ~ X is legally inconsistent with ‘‘knowledge of’’ X. Similarly, if recklessness with respect to the existence of X is what the legislature has required, then the defendant’s belief in ~ X will exculpate her unless she was reckless in believing ~ X (she was aware of a substantial and unjustifiable risk of X). (See MPC § 2.02(2)(c), definition of recklessness). If the legislature requires only negligence with respect to X, the defendant’s belief in ~ X will exculpate only if the belief is not negligent. Finally, if the legislature makes the existence of X a matter of strict liability—no mens rea is required with respect to X—then the defendant’s mistake regarding the existence of X is immaterial to her guilt under the statute. (The application of this approach to mistakes when the crime requires acting with the ‘‘purpose’’ of producing X or engaging in X is not as straightforward. Although some commentators have suggested that the defendant’s belief in ~ X negates any purpose to produce or engage in X, the better analysis is that one can have a purpose to X in the criminal law sense even if one does not believe X will result. For example, if the Jackal takes what he knows is a one in one thousand shot at DeGaulle, hoping he will succeed in hitting him but believing he will not, he acts with criminal purpose. For if he hits DeGaulle and kills him, the homicide is surely purposeful. The Jackal will hardly be heard to claim that he lacked the required purpose merely because he believed his chances of success were poor.)

The reform here is really nothing more than the recognition that mens rea requirements logically entail certain treatment of mistakes, and that therefore there is no sense in treating exculpatory mistakes under a rubric separate from mens rea. The old approach is confusing and results in punishment for negligent, i.e., unreasonable, mistakes even though arguably a mens rea more culpable than negligence is statutorily required.

The new approach to exculpatory mistakes has also been extended beyond mistakes regarding elements of crimes to mistakes that bear on defense. Under the traditional approach, for example, a defendant who makes an unreasonable mistake regarding whether he is being attacked and thus may employ force in self-defense is deprived of the privilege of employing such defensive force. Under the new approach, exemplified by the Model Penal Code, the defendant retains the privilege except against a charge that reflects his actual culpability. Thus, if his mistake is only negligent, he may be convicted only of the negligent use of force. If it is a reckless mistake, he may be charged with reckless use of force. But if he has been genuinely mistaken, and he would have been entitled to use force had things been as he believed, he may not be charged with any degree of use of force higher than recklessness.

The Model Penal Code has also extended its elements approach to cover cases where the defendant’s mistake exculpates him of the offense he otherwise committed but inculpates him in a different crime, one he mistakenly believed he was committing. Thus, if the defendant kills Polly, honestly mistaking her for a swan, and killing swans is itself prohibited, then the defendant may be held liable under the Model Penal Code § 2.04(2) for that degree of homicide that carries the same penalty as the crime (swanicide) he believed he was committing. In essence, the Model Penal Code constructs an artificial crime out of an attempt to commit one crime and commission of the actus reus (prohibited conduct) of another.

If the reforms above are basically analytic, the reformers were also prescriptive when it came to exculpatory mistakes about the existence or meaning of the criminal statutes themselves as opposed to mistakes about matters of fact or law that are elements of particular criminal statutes. They urged retention of the traditional position that ignorance of the criminal law did not in most cases excuse one from criminal liability. The Model Penal Code is illustrative. Section 2.02(9) prescribes that in interpreting a criminal statute, knowledge or belief regarding the existence or meaning of the criminal statute is not to be read into the statute as a required mental state. And section 2.04(3) lays down conditions for a quite narrow excuse of mistake of criminal law. (Basically, under MPC § 2.04(3), mistakes regarding the existence or meaning of a criminal statute excuse only when the statute has not been published or when the defendant has relied on an official but erroneous interpretation of the statute.)

Problems with Mistakes of Law

However, a problem surfaces at this point. Under the Model Penal Code and the approaches of most commentators, mistakes as to the meaning or existence of the criminal statute under which one is punished do not exculpate, whereas other mistakes of both law and fact may. But how is the line between these types of mistakes to be drawn? A legal positivist will regard law and its meaning as a species of fact. Whether there is a law against rape will depend upon facts about the legislature (whose existence and powers are themselves the product of other facts)— what it enacted, and so on—and the meaning of that law will depend upon facts about complex linguistic and judicial practices.

Moreover, at least for purposes of the criminal law, the proper jurisprudential stance arguably must be positivism: the principle of legality (i.e., that criminal laws must be enacted prior to the conduct they criminalize) and its corollary principle against vagueness can be viewed as demanding that the existence and meaning of criminal statutes be accessible to those subject to them in the manner that only facts, not values, can be.

Now what facts constitute the existence or meaning of the criminal law, mistakes as to which do not excuse, as opposed to those other facts, mistakes as to which do excuse? Let us consider some variations on the well-known hypothetical case of Lady Eldon, who returns to England from a visit to France with some French lace that she has purchased in her luggage. When asked at customs if she has any dutiable items to declare, she replies ‘‘no.’’ French lace is a dutiable item. Has Lady Eldon committed a crime? (Wharton, p. 304). See F. Wharton, Criminal Law (1932): 304 n.9. (In the actual hypothetical, Lady Eldon’s mistake is inculpatory, not exculpatory.)

Consider two variants of this hypothetical case. In the first variant, there is a law against failing to declare dutiable items. Those items are listed in regulations that are changed from time to time. Lady Eldon mistakenly believes French lace has been taken off the list. In the second variant, the criminal law itself states ‘‘it is a crime to fail to declare . . . French lace.’’ Lady Eldon mistakenly believes that there is no such crime. In the latter case it seems clear that she has made a mistake about the existence and meaning of the criminal law. But how is this case different in any material way from the former? Moreover, suppose she had read the regulations in the former case and misperceived the word ‘‘French’’ as ‘‘Flemish.’’ How would that mistake be any different from, say, her perceiving the lace she is carrying as Flemish lace rather than as French lace, a mistake that would exculpate her if the statute requires a mental state of purpose, knowledge, or recklessness with respect to whether the lace one is failing to declare is French lace? Both mistakes are ‘‘factual.’’

Several approaches are taken to defining the boundary between those mistakes of law that do not excuse (except under rarefied conditions) and those mistakes of both law and fact that can excuse. The problem is usually formulated as distinguishing those mistakes of law that relate to the existence or meaning of the criminal statute and those mistakes of law that do not, with mistakes of fact being a third and nonproblematic kind of mistake. Because all mistakes of law are particular kinds of mistakes of fact, all three kinds of mistake are capable of collapsing into one another. But even if we accept that ordinary mistakes of fact are nonproblematic—they clearly can negate criminal liability by negating a required mental state—drawing the boundary between those mistakes of law that can negate criminal liability and those that rarely do is surely difficult conceptually.

Some identify the distinction as one between mistakes regarding the law under which one is prosecuted (‘‘same law’’ mistakes) and mistakes regarding other laws (‘‘different law’’ mistakes). Examples to illustrate the distinction include prosecution under a bigamy statute of one who knew about the proscription of bigamy but mistakenly believed his divorce from his first wife was legally valid; and prosecution under a theft statute of one who drives her car away from a garage after refusing to pay the mechanic what she regards as an excessive bill without realizing that under the law, the mechanic has a possessory lien on the car until the bill is paid; and the case in which defendant, unaware that under the law of property, the paneling he had put in his apartment had become the property of his landlord, tore up the paneling and was prosecuted for destroying the property of another.

The same law/different law approach requires that we have a theory about how to individuate laws. But no one has offered such a theory. Moreover, the prospects of coming up with one are bleak. How one individuates laws— for example, whether one considers the law of property, including the law regarding mechanics’ liens or emblements, as separate from or as part of the law of theft or the law of destruction of others’ property—looks to be quite arbitrary in the abstract without identifying the principles and policies that motivate the individuation. For example, different degrees of culpability might attach to different legal mistakes, though it is doubtful that differences in culpability will be consistent enough to make clear seams of individuation within the otherwise seamless web of the law.

The same criticism applies to other attempts to differentiate those mistakes of law that almost never negate criminal liability from those that frequently do. Some identify the distinction as one between mistakes of criminal law and mistakes of civil law. But mistakes of criminal law can be exculpatory when one criminal law refers to another. For example, conviction under a law criminalizing knowingly receiving stolen property can be defeated by the defendant’s mistake, not as to the existence of that law, but as to whether the property he received is stolen. That mistake is one of criminal law.

Another proposed solution is to distinguish mistakes of law that relate to elements of a criminal offense and mistakes of law that relate to the existence and meaning of the criminal law governing the transaction. But this elements/ governing-law distinction between mistakes of law requires that we be able to distinguish between the meaning of a criminal law and the meaning of its elements.

The Analytic Solution

Despite these problems in distinguishing mistakes of law that can exculpate from the mistakes of law that do not, the modern approach possesses the key to their solution. For the modern approach says that: (1) mistakes exculpate when they negate the mens rea required by the legislature; and (2) the legislature will be presumed not to require knowledge of the existence or meaning of the criminal law. If we put aside (2) and look at (1), we can avoid the problems of classification by asking what mental states with regard to what things did the legislature require. If, for example, the legislature requires knowledge of an element, then regardless how the defendant’s mistake regarding that element is classified (reasonable or unreasonable), the mistake entails that she is not criminally liable.

This solution—the analytic solution—works so long as the legislature has been relatively clear about what mental states are required for various elements. But if the legislature has not been clear, and its intent must be interpreted through recourse to more basic policies and principles, matters become difficult. For example, ignorance of different aspects of the law will reveal varying degrees of culpability. The fact that one does not know it is illegal to take what belongs to another may not diminish one’s culpability one whit, whereas the fact that one does not know that the paneling he installs in his apartment is the property of one’s landlord does reduce or eliminate one’s culpability for later destroying it. But the degree to which culpability is reduced by legal mistakes does not provide a fine enough instrument for separating those mistakes into two categories. There are countless criminal statutes, ignorance of which is widespread, and violation of which as a result of such ignorance is surely nonculpable. And there are many mistakes regarding civil law matters that, if they result in criminal violations, would not lead us to deem those violations nonculpable. (Consider someone who, in being prosecuted for fraud, claims he did not know that lying about the existence of the item promised was lying about a material term of the contract, the materiality of the lie being a component of criminal fraud.)

The only other consideration that might conceivably assist the individuation of law required when the legislature has been silent about mens rea is the claim, frequently voiced, that the criminal law cannot as a conceptual matter require mens rea as to its own existence. However, this argument is unsound. There is nothing in the least bit paradoxical about the law’s being selfreferential, especially if we separate the conduct that is proscribed from the mental state accompanying it. Indeed, as proof that requiring one to be aware of a criminal statute is an entirely possible condition for holding him liable under the statute, there are actual cases, such as Ratzlaf v. United States, 510 U.S. 135 (1994), interpreting criminal statutes to make awareness of their existence a necessary condition for violation.

A third policy that might aid in the individuation of mistakes of law required under the Model Penal Code and like approaches when the legislature is silent about mental state is that of not encouraging ignorance of law, which some believe allowing mistakes of law to exculpate would do. Now while it is true in some sense that we do not wish to encourage ignorance of law, it is also true that we do not realistically expect, nor do we wish to encourage, encyclopedic knowledge of law, even criminal law (to the extent it can be separated from law generally). It would be crazily obsessive even to want judges and lawyers to possess such encyclopedic knowledge, much less the general population. Indeed, one who attains such knowledge is more likely culpable for having done so at the expense of more pressing concerns than is one who in ignorance runs afoul of some recondite legal requirement.

To summarize, the law of exculpatory mistakes distinguishes between mistakes regarding the existence and meaning of the criminal laws themselves and other mistakes of both law and fact. Although the treatment of all mistakes in either category is controlled by the legislature’s specification of mens rea, when the legislature has been silent or ambiguous regarding mens rea, the distinction between these categories of mistakes becomes important in interpreting the required mens rea. However, any line that can be drawn to separate these categories appears quite arbitrary: laws are constituted by facts, and the line between the criminal law and the rest of the law can be drawn at an indefinite number of places. Moreover, the principles and policies that might rescue us from arbitrariness in drawing such lines—for example, culpability concerns and concerns with not encouraging ignorance— fail to track any consistent boundary line that might be drawn.


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