DIXON v. UNITED STATES

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CASES ADJUDGED
IN THE
SUPREME COURT OF THE UNITED STATES
AT
OCTOBER TERM, 2005
DIXON v. UNITED STATES
certiorari to the united states court of appeals for
the fifth circuit
No. 05–7053. Argued April 25, 2006—Decided June 22, 2006
Petitioner was charged with receiving a firearm while under indictment
in violation of 18 U. S. C. § 922(n) and with making false statements in
connection with the acquisition of a firearm in violation of § 922(a)(6).
She admitted at trial that she knew she was under indictment when she
purchased the firearms and knew that doing so was a crime, but claimed
that she was acting under duress because her boyfriend had threatened
to harm her and her daughters if she did not buy the guns for him.
Bound by Fifth Circuit precedent, the District Court declined her re
quest for a jury instruction placing upon the Government the burden to
disprove, beyond a reasonable doubt, her duress defense. Instead, the
jury was instructed that petitioner had the burden to establish her de
fense by a preponderance of the evidence. She was convicted, and the
Fifth Circuit affirmed.
Held:
1. The jury instructions did not run afoul of the Due Process Clause.
The crimes of conviction require that petitioner have acted “knowingly,”
§ 922(a)(6)—which “merely requires proof of knowledge of the facts that
constitute the offense,” Bryan v. United States, 524 U. S. 184, 193—or
“willfully,” § 924(a)(1)(D)—which requires acting “with knowledge that
[the] conduct was unlawful,” ibid. Thus, the Government bore the bur
den of proving beyond a reasonable doubt that petitioner knew that she
was making false statements and knew that she was breaking the law
when she acquired a firearm while under indictment. It clearly met its
1

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2 DIXON v. UNITED STATES
Syllabus
burden when petitioner testified to that effect. Petitioner contends
that she cannot have formed the necessary mens rea because she did
not freely choose to commit the crimes. However, while the duress
defense may excuse conduct that would otherwise be punishable, see
United States v. Bailey, 444 U. S. 394, 409–410, the existence of duress
normally does not controvert any of the elements of the offense itself.
The fact that petitioner’s crimes are statutory offenses with no counter
part in the common law supports this conclusion. The jury instructions
were consistent with the requirement that the Government prove the
mental states specified in §§ 922(a)(6) and 924(a)(1)(D) and did not run
afoul of due process by placing the burden on petitioner to establish
duress by a preponderance of the evidence. Pp. 5–8.
2. Modern common law does not require the Government to bear the
burden of disproving petitioner’s duress defense beyond a reasonable
doubt. The long-established common-law rule, which places the burden
of proving that defense on the defendant, was not upset by Davis v.
United States, 160 U. S. 469. There, the Court interpreted a defend
ant’s insanity to controvert the necessary mens rea for a murder com
mitted “feloniously, wilfully, and of his malice aforethought,” id., at 474,
and required the Government to prove the defendant’s sanity beyond a
reasonable doubt because the evidence tending to prove insanity also
tended to disprove an essential element of the offense. The duress evi
dence that petitioner adduced at trial does not contradict or tend to
disprove any element of her statutory offenses. She is also not helped
by the resulting “Davis rule,” which was not constitutionally mandated,
and which Congress overruled by statute, requiring a defendant to
prove insanity by clear and convincing evidence.
Petitioner’s reliance on Davis also ignores the fact that federal crimes
are “solely creatures of statute,” Liparota v. United States, 471 U. S.
419, 424, and thus the Court must effectuate the duress defense as
Congress “may have contemplated” it in the context of these specific
offenses, United States v. Oakland Cannabis Buyers’ Cooperative,
532 U. S. 483, 490, n. 3. The Court can assume that, when passing the
relevant 1968 Act, Congress was familiar with the long-established
common-law rule and the rule of McKelvey v. United States, 260 U. S.
353, 357—that the one relying on an affirmative defense must set it up
and establish it—and would have expected federal courts to apply a
similar approach to any affirmative defense or excuse for violating the
new law. To accept petitioner’s contrary hypothesis that Davis dra
matically upset well-settled law would require an overwhelming consen
sus among federal courts placing the burden on the Government, but
conflict among the Circuits demonstrates that such consensus has never
existed. For a similar reason, no weight is due the 1962 Model Penal

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Opinion of the Court
Code. There is no evidence that Congress endorsed the Code’s views
or incorporated them into the 1968 Act. In fact, when Congress
amended the Act to add a mens rea requirement, it punished “willful”
violations, a mental state not embraced by the Code. Effectuating the
affirmative defense as Congress may have contemplated it, the Court
presumes that, in the context of the firearms offenses here and the long
established common-law rule, Congress intended petitioner to bear the
burden of proving the duress defense by a preponderance of the evi
dence. Pp. 8–17.
413 F. 3d 520, affirmed.
Stevens, J., delivered the opinion of the Court, in which Roberts, C. J.,
and Scalia, Kennedy, Thomas, Ginsburg, and Alito, JJ., joined. Ken
nedy, J., filed a concurring opinion, post, p. 17. Alito, J., filed a concur
ring opinion, in which Scalia, J., joined, post, p. 19. Breyer, J., filed a
dissenting opinion, in which Souter, J., joined, post, p. 20.
J. Craig Jett, by appointment of the Court, 547 U. S. 1002,
argued the cause for petitioner. With him on the briefs was
Jeffrey T. Green.
Irving L. Gornstein argued the cause for the United
States. On the brief were Solicitor General Clement, As
sistant Attorney General Fisher, Deputy Solicitor General
Dreeben, Deanne E. Maynard, and Deborah Watson.*
Justice Stevens delivered the opinion of the Court.
In January 2003, petitioner Keshia Dixon purchased multi
ple firearms at two gun shows, during the course of which
she provided an incorrect address and falsely stated that she
was not under indictment for a felony. As a result of these
illegal acts, petitioner was indicted and convicted on one
count of receiving a firearm while under indictment in viola
tion of 18 U. S. C. § 922(n) and eight counts of making false
statements in connection with the acquisition of a firearm in
violation of § 922(a)(6). At trial, petitioner admitted that
*Elliot H. Scherker, Julissa Rodriguez, Karen M. Gottlieb, Peter Gold
berger, and Pamela Harris filed a brief for the National Association of
Criminal Defense Lawyers et al. as amici curiae urging reversal.

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4 DIXON v. UNITED STATES
Opinion of the Court
she knew she was under indictment when she made the pur
chases and that she knew doing so was a crime; her defense
was that she acted under duress because her boyfriend
threatened to kill her or hurt her daughters if she did not
buy the guns for him.
Petitioner contends that the trial judge’s instructions to
the jury erroneously required her to prove duress by a pre
ponderance of the evidence instead of requiring the Govern
ment to prove beyond a reasonable doubt that she did not act
under duress. The Court of Appeals rejected petitioner’s
contention, 413 F. 3d 520 (CA5 2005); given contrary treat
ment of the issue by other federal courts,1 we granted certio
rari, 546 U. S. 1135 (2006).
I
At trial, in her request for jury instructions on her defense
of duress, petitioner contended that she “should have the
burden of production, and then that the Government should
be required to disprove beyond a reasonable doubt the du
ress.” App. 300. Petitioner admitted that this request was
contrary to Fifth Circuit precedent, and the trial court, cor
rectly finding itself bound by Circuit precedent, denied peti
tioner’s request. Ibid. Instead, the judge’s instructions to
the jury defined the elements of the duress defense 2 and
1 Cf., e. g., United States v. Talbott, 78 F. 3d 1183, 1186 (CA7 1996) (per
curiam); United States v. Riffe, 28 F. 3d 565, 568, n. 2 (CA6 1994); United
States v. Simpson, 979 F. 2d 1282, 1287 (CA8 1992).
2 There is no federal statute defining the elements of the duress defense.
We have not specified the elements of the defense, see, e. g., United States
v. Bailey, 444 U. S. 394, 409–410 (1980), and need not do so today. Instead,
we presume the accuracy of the District Court’s description of these ele
ments: (1) The defendant was under an unlawful and imminent threat of
such a nature as to induce a well-grounded apprehension of death or seri
ous bodily injury; (2) the defendant had not recklessly or negligently
placed herself in a situation in which it was probable that she would be
forced to perform the criminal conduct; (3) the defendant had no reason
able, legal alternative to violating the law, that is, a chance both to refuse
to perform the criminal act and also to avoid the threatened harm; and,

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Opinion of the Court
stated that petitioner has “the burden of proof to establish
the defense of duress by a preponderance of the evidence.”
Id., at 312.
Petitioner argues here, as she did in the District Court
and the Court of Appeals, that federal law requires the Gov
ernment to bear the burden of disproving her defense be
yond a reasonable doubt and that the trial court’s erroneous
instruction on this point entitles her to a new trial. There
are two aspects to petitioner’s argument in support of her
proposed instruction that merit separate discussion. First,
petitioner contends that her defense “controverted the mens
rea required for conviction” and therefore that the Due Proc
ess Clause requires the Government to retain the burden of
persuasion on that element. Brief for Petitioner 41. Sec
ond, petitioner argues that the Fifth Circuit’s rule is “con
trary to modern common law.” Id., at 14.
II
The crimes for which petitioner was convicted require that
she have acted “knowingly, ” § 922(a)(6), or “willfully, ”
§ 924(a)(1)(D).3 As we have explained, “unless the text of
the statute dictates a different result, the term ‘knowingly’
merely requires proof of knowledge of the facts that con
stitute the offense.” Bryan v. United States, 524 U. S. 184,
193 (1998) (footnote omitted). And the term “willfully” in
§ 924(a)(1)(D) requires a defendant to have “acted with
knowledge that his conduct was unlawful.” Ibid. In this
case, then, the Government bore the burden of proving be
yond a reasonable doubt that petitioner knew she was mak
(4) that a direct causal relationship may be reasonably anticipated between
the criminal act and the avoidance of the threatened harm. See App.
312–313; see generally United States v. Harper, 802 F. 2d 115, 118 (CA5
1986).
3 Although § 922(n) does not contain a mens rea requirement, the rele
vant sentencing provision, § 924(a)(1)(D), requires that a violation be com
mitted willfully.

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6 DIXON v. UNITED STATES
Opinion of the Court
ing false statements in connection with the acquisition of
firearms and that she knew she was breaking the law when
she acquired a firearm while under indictment. See In re
Winship, 397 U. S. 358, 364 (1970). Although the Govern
ment may have proved these elements in other ways, it
clearly met its burden when petitioner testified that she
knowingly committed certain acts—she put a false address
on the forms she completed to purchase the firearms, falsely
claimed that she was the actual buyer of the firearms, and
falsely stated that she was not under indictment at the time
of the purchase—and when she testified that she knew she
was breaking the law when, as an individual under indict
ment at the time, she purchased a firearm. App. 221–222.
Petitioner contends, however, that she cannot have formed
the necessary mens rea for these crimes because she did not
freely choose to commit the acts in question. But even if
we assume that petitioner’s will was overborne by the
threats made against her and her daughters, she still knew
that she was making false statements and knew that she was
breaking the law by buying a firearm. The duress defense,
like the defense of necessity that we considered in United
States v. Bailey, 444 U. S. 394, 409–410 (1980), may excuse
conduct that would otherwise be punishable, but the exist
ence of duress normally does not controvert any of the ele
ments of the offense itself.4 As we explained in Bailey,
“[c]riminal liability is normally based upon the concurrence
of two factors, ‘an evil-meaning mind [and] and evil-doing
hand . . . .’ ” Id., at 402 (quoting Morissette v. United States,
4 As the Government recognized at oral argument, there may be crimes
where the nature of the mens rea would require the Government to dis
prove the existence of duress beyond a reasonable doubt. See Tr. of Oral
Arg. 26–27; see also, e. g., 1 W. LaFave, Substantive Criminal Law § 5.1,
p. 333 (2d ed. 2003) (hereinafter LaFave) (explaining that some common
law crimes require that the crime be done “ ‘maliciously’ ”); Black’s Law
Dictionary 968 (7th ed. 1999) (defining malice as “[t]he intent, without jus
tification or excuse, to commit a wrongful act”).

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342 U. S. 246, 251 (1952)). Like the defense of necessity, the
defense of duress does not negate a defendant’s criminal
state of mind when the applicable offense requires a defend
ant to have acted knowingly or willfully; instead, it allows
the defendant to “avoid liability . . . because coercive condi
tions or necessity negates a conclusion of guilt even though
the necessary mens rea was present.” Bailey, 444 U. S., at
402.5
The fact that petitioner’s crimes are statutory offenses
that have no counterpart in the common law also supports
our conclusion that her duress defense in no way disproves
an element of those crimes. We have observed that “[t]he
definition of the elements of a criminal offense is entrusted
to the legislature, particularly in the case of federal crimes,
which are solely creatures of statute.” Liparota v. United
States, 471 U. S. 419, 424 (1985). Here, consistent with the
movement away from the traditional dichotomy of general
versus specific intent and toward a more specifically defined
hierarchy of culpable mental states, see Bailey, 444 U. S.,
at 403–404, Congress defined the crimes at issue to punish
defendants who act “knowingly,” § 922(a)(6), or “willfully,”
§ 924(a)(1)(D). It is these specific mental states, rather than
some vague “evil mind,” Brief for Petitioner 42, or “ ‘crimi
nal’ intent,” Martin v. Ohio, 480 U. S. 228, 235 (1987), that
the Government is required to prove beyond a reasonable
doubt, see Patterson v. New York, 432 U. S. 197, 211, n. 12
(1977) (“The applicability of the reasonable-doubt standard,
5 Professor LaFave has explained the duress defense as follows:
“The rationale of the defense is not that the defendant, faced with the
unnerving threat of harm unless he does an act which violates the literal
language of the criminal law, somehow loses his mental capacity to commit
the crime in question. Nor is it that the defendant has not engaged in
a voluntary act. Rather it is that, even though he has done the act
the crime requires and has the mental state which the crime requires,
his conduct which violates the literal language of the criminal law is
excused . . . .” 2 LaFave § 9.7(a), at 73 (footnotes omitted).

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8 DIXON v. UNITED STATES
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however, has always been dependent on how a State defines
the offense that is charged in any given case”). The jury
instructions in this case were consistent with this require
ment and, as such, did not run afoul of the Due Process
Clause when they placed the burden on petitioner to estab
lish the existence of duress by a preponderance of the
evidence.
III
Having found no constitutional basis for placing upon the
Government the burden of disproving petitioner’s duress de
fense beyond a reasonable doubt, we next address petition
er’s argument that the modern common law requires the
Government to bear that burden. In making this argument,
petitioner recognizes that, until the end of the 19th century,
common-law courts generally adhered to the rule that “the
proponent of an issue bears the burden of persuasion on the
factual premises for applying the rule.” Fletcher, Two
Kinds of Legal Rules: A Comparative Study of Burden-of-
Persuasion Practices in Criminal Cases, 77 Yale L. J. 880, 898
(1967–1968). In petitioner’s view, however, two important
developments have established a contrary common-law rule
that now prevails in federal courts: this Court’s decision in
Davis v. United States, 160 U. S. 469 (1895), which placed the
burden on the Government to prove a defendant’s sanity, and
the publication of the Model Penal Code in 1962.
Although undisputed in this case, it bears repeating that,
at common law, the burden of proving “affirmative de
fenses—indeed, ‘all . . . circumstances of justification, excuse
or alleviation’—rested on the defendant.” Patterson, 432
U. S., at 202 (quoting 4 W. Blackstone, Commentaries *201);
see also Martin v. Ohio, 480 U. S., at 235; Mullaney v. Wil
bur, 421 U. S. 684, 693 (1975). This common-law rule ac
cords with the general evidentiary rule that “the burdens of
producing evidence and of persuasion with regard to any
given issue are both generally allocated to the same party.”
2 J. Strong, McCormick on Evidence § 337, p. 415 (5th ed.

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1999). And, in the context of the defense of duress, it ac
cords with the doctrine that “where the facts with regard to
an issue lie peculiarly in the knowledge of a party, that party
has the burden of proving the issue.” Id., at 413. Although
she claims that the common-law rule placing the burden on
a defendant to prove the existence of duress “was the prod
uct of flawed reasoning,” petitioner accepts that this was the
general rule, at least until this Court’s decision in Davis.
Brief for Petitioner 18. According to petitioner, however,
Davis initiated a revolution that overthrew the old common
law rule and established her proposed rule in its place.
Davis itself, however, does not support petitioner’s posi
tion. In that case, we reviewed a defendant’s conviction for
having committed murder “feloniously, wilfully, and of his
malice aforethought.” 160 U. S., at 474. It was undisputed
that the prosecution’s evidence, “if alone considered, made it
the duty of the jury to return a verdict of guilty of the crime
charged”; the defendant, however, adduced evidence at trial
tending to show that he did not have the mental capacity to
form the requisite intent. Id., at 475. At issue before the
Court was the correctness of the trial judge’s instruction to
the jury that the law “ ‘presumes every man is sane, and the
burden of showing it is not true is upon the party who as
serts it.’ ” Id., at 476. Under this instruction, “if the evi
dence was in equilibrio as to the accused being sane, that is,
capable of comprehending the nature and effect of his acts,
he was to be treated just as he would be if there were no
defence of insanity or if there were an entire absence of proof
that he was insane.” Id., at 479.
In reversing the defendant’s conviction, we found our
selves “unable to assent to the doctrine that in a prosecution
for murder . . . it is the duty of the jury to convict where the
evidence is equally balanced on the issue as to the sanity of
the accused at the time of the killing.” Id., at 484 (emphasis
added). Instead, we concluded that this defendant was
“entitled to an acquittal of the specific crime charged if upon

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10 DIXON v. UNITED STATES
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all the evidence there is reasonable doubt whether he was
capable in law of committing [the] crime.” Ibid. (emphasis
added). Our opinion focused on the “definition of murder,”
explaining that “it is of the very essence of that heinous
crime that it be committed by a person of ‘sound memory
and discretion,’ and with ‘malice aforethought.’ ” Ibid.
Reviewing “the adjudged cases” and “elementary treatises
upon criminal law,” we found that “[a]ll admit that the crime
of murder necessarily involves the possession by the accused
of such mental capacity as will render him criminally respon
sible for his acts.” Id., at 485. Thus, when we ultimately
found that the burden of proving the accused’s sanity rested
on the Government, our holding rested on the conclusion that
“[Davis’] guilt cannot be said to have been proved be
yond a reasonable doubt—his will and his acts cannot
be held to have joined in perpetrating the murder
charged—if the jury, upon all the evidence, have a rea
sonable doubt whether he was legally capable of commit
ting crime, or (which is the same thing) whether he wil
fully, deliberately, unlawfully, and of malice aforethought
took the life of the deceased. As the crime of murder
involves sufficient capacity to distinguish between right
and wrong, the legal interpretation of every verdict of
guilty as charged is that the jury believed from all the
evidence beyond a reasonable doubt that the accused
was guilty, and was therefore responsible, criminally, for
his acts. How then upon principle or consistently with
humanity can a verdict of guilty be properly returned,
if the jury entertain a reasonable doubt as to the exist
ence of a fact which is essential to guilt, namely, the
capacity in law of the accused to commit that crime?”
Id., at 488.
Our opinion in Davis, then, interpreted a defendant’s san
ity to controvert the necessary mens rea for the crime of

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murder committed “feloniously, wilfully, and of his malice
aforethought,” id., at 474, as “[o]ne who takes human life can
not be said to be actuated by malice aforethought, or to have
deliberately intended to take life, or to have ‘a wicked, de
praved, and malignant heart,’ . . . unless at the time he had
sufficient mind to comprehend the criminality or the right
and wrong of such an act,” id., at 485. We required the Gov
ernment to prove the defendant’s sanity beyond a reasonable
doubt because the evidence that tended to prove insanity
also tended to disprove an essential element of the offense
charged. See Davis v. United States, 165 U. S. 373, 378
(1897) (“[T]he fact of sanity, as any other essential fact in
the case, must be established to the satisfaction of the jury
beyond a reasonable doubt” (emphasis added)). Whether or
not this reasoning correctly treated insanity as negating the
mens rea for murder as defined in the statute at issue,
cf. n. 4, supra, it does not help petitioner: The evidence of
duress she adduced at trial does not contradict or tend to
disprove any element of the statutory offenses that she
committed.
Nor does the proposition for which Davis has come to
stand help petitioner’s cause. Although written more nar
rowly in the context of a prosecution for the crime of murder,
Davis was later interpreted to establish a general “rule for
federal prosecutions . . . that an accused is ‘entitled to an
acquittal of the specific crime charged if upon all the evi
dence there is reasonable doubt whether he was capable in
law of committing crime.’ ” Leland v. Oregon, 343 U. S. 790,
797 (1952) (quoting Davis, 160 U. S., at 484); see also Lynch
v. Overholser, 369 U. S. 705, 713 (1962) (explaining that the
Davis rule applied in all federal courts). After Davis, if a
federal defendant introduced sufficient evidence to raise a
reasonable doubt as to his sanity, it was sufficient to create
a question for the jury on which the Government bore the
ultimate burden of persuasion beyond a reasonable doubt.

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12 DIXON v. UNITED STATES
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See, e. g., Hall v. United States, 295 F. 2d 26, 28 (CA4 1961);
Holloway v. United States, 148 F. 2d 665, 666 (CADC 1945);
Post v. United States, 135 F. 1, 10 (CA5 1905).
In apparent recognition of the fact that Davis relied on
the heightened mens rea applicable to the particular statute
at issue, we held in Leland that this rule was not constitu
tionally mandated, 343 U. S., at 797, and Congress overruled
it by statute in 1984, requiring a defendant to prove his in
sanity by clear and convincing evidence, 98 Stat. 2057, codi
fied at 18 U. S. C. § 17(b). Moreover, Congress has treated
the defense of insanity differently from that of duress not
only by codifying it but by requiring defendants who intend
to rely on an insanity defense to provide advance notice to
the Government. See Fed. Rule Crim. Proc. 12.2(a). Thus,
even if the rule arising from Davis may have once been rele
vant to an evaluation of other affirmative defenses, Congress’
differential treatment of the insanity defense and its rejec
tion of the Davis rule are inconsistent with petitioner’s invi
tation to follow Davis’ lead in this case.
Indeed, petitioner’s reliance on Davis ignores the fact that
federal crimes “are solely creatures of statute,” Liparota,
471 U. S., at 424, and therefore that we are required to effec
tuate the duress defense as Congress “may have contem
plated” it in the context of these specific offenses, United
States v. Oakland Cannabis Buyers’ Cooperative, 532 U. S.
483, 491, n. 3 (2001) (internal quotation marks omitted); see
also id., at 499 (Stevens, J., concurring in judgment) (ex
plaining that Court was addressing whether the statute
at issue foreclosed a necessity defense to specific charges
brought under the statute); Bailey, 444 U. S., at 410 (“We
need not speculate now, however, on the precise contours
of whatever defenses of duress or necessity are available
against charges brought under [18 U. S. C.] § 751(a)”). The
offenses at issue in this case were created by statute in 1968,
when Congress enacted the Omnibus Crime Control and Safe
Streets Act (hereinafter Safe Streets Act or Act). See 82

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Stat. 197. There is no evidence in the Act’s structure or
history that Congress actually considered the question of
how the duress defense should work in this context, and
there is no suggestion that the offenses at issue are incom
patible with a defense of duress.6 Cf. Oakland Cannabis
Buyers’ Cooperative, 532 U. S., at 491. Assuming that a de
fense of duress is available to the statutory crimes at issue,7
then, we must determine what that defense would look like
as Congress “may have contemplated” it.
As discussed above, the common law long required the
defendant to bear the burden of proving the existence of
duress. Similarly, even where Congress has enacted an
affirmative defense in the proviso of a statute, the “settled
rule in this jurisdiction [is] that an indictment or other
pleading . . . need not negative the matter of an exception
made by a proviso or other distinct clause . . . and that it is
incumbent on one who relies on such an exception to set it
up and establish it.” McKelvey v. United States, 260 U. S.
353, 357 (1922); see also United States v. Dickson, 15 Pet.
141, 165 (1841) (calling this “the general rule of law which
has always prevailed, and become consecrated almost as a
maxim in the interpretation of statutes”). Even though the
Safe Streets Act does not mention the defense of duress, we
can safely assume that the 1968 Congress was familiar with
6 While Congress’ findings in support of the Safe Streets Act show that
Congress was concerned because “the ease with which any person can
acquire firearms . . . is a significant factor in the prevalence of lawlessness
and violent crime in the United States,” § 901(a)(2), 82 Stat. 225, it would
be unrealistic to read this concern with the proliferation of firearm-based
violent crime as implicitly doing away with a defense as strongly rooted
in history as the duress defense, see, e. g., 4 W. Blackstone, Commentaries
on the Laws of England 30 (1769).
7 We have previously made this assumption when addressing common
law affirmative defenses, see United States v. Oakland Cannabis Buyers’
Cooperative, 532 U. S. 483, 491 (2001); Bailey, 444 U. S., at 410, and the
parties give us no reason to question it here.

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14 DIXON v. UNITED STATES
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both the long-established common-law rule 8 and the rule ap
plied in McKelvey and that it would have expected federal
courts to apply a similar approach to any affirmative defense
that might be asserted as a justification or excuse for violat
ing the new law.9
This conclusion is surely more reasonable than petitioner’s
hypothesis that Davis dramatically upset a well-settled rule
of law. Petitioner cites only one federal case decided before
1968 for the proposition that it has been well established in
federal law that the Government bears the burden of dis
proving duress beyond a reasonable doubt. But that case
involved a defendant’s claim that he “lacked the specific
intent to defraud required by the statute for the reason
that he committed the offense under duress and coercion.”
Johnson v. United States, 291 F. 2d 150, 152 (CA8 1961).
Thus, when the Court of Appeals explained that “there is no
burden upon the defendant to prove his defense of coercion,”
id., at 155, that statement is best understood in context as a
corollary to the by-then-unremarkable proposition that “the
burden of proof rests upon the Government to prove the de
fendant’s guilt beyond a reasonable doubt,” ibid. Properly
understood, Johnson provides petitioner little help in her up
hill struggle to prove that a dramatic shift in the federal
common-law rule occurred between Davis and the enactment
of the Safe Streets Act in 1968.
Indeed, for us to be able to accept petitioner’s proposition,
we would need to find an overwhelming consensus among
8 Indeed, when a congressional committee did consider codifying the du
ress defense, it would have had the courts determine the defense “accord
ing to the principles of the common law as they may be interpreted in the
light of reason and experience.” S. 1437, 95th Cong., 2d Sess., § 501
(1978).
9 Duress, like the defense at issue in McKelvey, is an excuse that allows
an exception from liability. See, e. g., 2 LaFave § 9.7, at 72 (“The rationale
of the defense of duress is that the defendant ought to be excused when
he ‘is the victim of a threat that a person of reasonable moral strength
could not fairly be expected to resist’ ”).

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15 Cite as: 548 U. S. 1 (2006)
Opinion of the Court
federal courts that it is the Government’s burden to disprove
the existence of duress beyond a reasonable doubt. The ex
istence today of disagreement among the Federal Courts of
Appeals on this issue, however—the very disagreement that
caused us to grant certiorari in this case, see n. 1, supra—
demonstrates that no such consensus has ever existed. See
also post, at 25–27 (Breyer, J., dissenting) (discussing differ
ences in treatment of the duress defense by the various
Courts of Appeals). Also undermining petitioner’s argu
ment is the fact that, in 1970, the National Commission on
Reform of Federal Criminal Laws proposed that a defendant
prove the existence of duress by a preponderance of the
evidence. See 1 Working Papers 278. Moreover, while
there seem to be few, if any, post-Davis, pre-1968 cases plac
ing the burden on a defendant to prove the existence of
duress,10 or even discussing the issue in any way, this lack
of evidence does not help petitioner. The long-established
common-law rule is that the burden of proving duress rests
on the defendant. Petitioner hypothesizes that Davis fo
mented a revolution upsetting this rule. If this were true,
one would expect to find cases discussing the matter. But
no such cases exist.
It is for a similar reason that we give no weight to the
publication of the Model Penal Code in 1962. As petitioner
notes, the Code would place the burden on the government
to disprove the existence of duress beyond a reasonable
doubt. See ALI, Model Penal Code § 1.12, p. 88 (2001) (here
inafter Model Penal Code or Code) (stating that each element
10 In D’Aquino v. United States, 192 F. 2d 338, 358, n. 11 (CA9 1951), the
trial court instructed the jury that it would be warranted in acquitting
the defendant on the basis that she acted under duress “ ‘[i]f you believe
from the evidence that the defendant committed these acts that the Gov
ernment alleges . . . under a well grounded apprehension of immediate
death or serious bodily injury . . . .’ ” This instruction did not require the
Government to disprove duress beyond a reasonable doubt, and it seem
ingly placed the burden on the defendant to prove the existence of duress.

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16 DIXON v. UNITED STATES
Opinion of the Court
of an offense must be proved beyond a reasonable doubt);
§ 1.13(9)(c), at 91 (defining as an element anything that nega
tives an excuse for the conduct at issue); § 2.09, at 131–132
(establishing affirmative defense of duress). Petitioner ar
gues that the Code reflects “well established” federal law
as it existed at the time. Brief for Petitioner 25. But, as
discussed above, no such consensus existed when Congress
passed the Safe Streets Act in 1968. And even if we assume
Congress’ familiarity with the Code and the rule it would
establish, there is no evidence that Congress endorsed the
Code’s views or incorporated them into the Safe Streets Act.
In fact, the Act itself provides evidence to the contrary.
Despite the Code’s careful delineation of mental states, see
Model Penal Code § 2.02, at 94–95, the Safe Streets Act
attached no explicit mens rea requirement to the crime of
receiving a firearm while under indictment, § 924(a), 82 Stat.
233 (“Whoever violates any provision of this chapter . . . shall
be fined not more than $5,000 or imprisoned not more than
five years, or both”). And when Congress amended the Act
to impose a mens rea requirement, it punished people who
“willfully” violate the statute, see §104(a), 100 Stat. 456, a
mental state that has not been embraced by the Code, see
Model Penal Code § 2.02(2), at 94–95 (defining “purposely,”
“knowingly,” “recklessly,” and “negligently”); id., Explana
tory Note, at 97 (“Though the term ‘wilfully’ is not used in
the definitions of crimes contained in the Code, its currency
and its existence in offenses outside the criminal code sug
gest the desirability of clarification”). Had Congress in
tended to adopt the Code’s structure when it enacted or
amended the Safe Streets Act, one would expect the Act’s
form and language to adhere much more closely to that used
by the Code. It does not, and, for that reason, we cannot
rely on the Model Penal Code to provide evidence as to how
Congress would have wanted us to effectuate the duress de
fense in this context.

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17 Cite as: 548 U. S. 1 (2006)
Kennedy, J., concurring
IV
Congress can, if it chooses, enact a duress defense that
places the burden on the Government to disprove duress be
yond a reasonable doubt. In light of Congress’ silence on
the issue, however, it is up to the federal courts to effectuate
the affirmative defense of duress as Congress “may have con
templated” it in an offense-specific context. Oakland Can
nabis Buyers’ Cooperative, 532 U. S., at 491, n. 3 (internal
quotation marks omitted). In the context of the firearms
offenses at issue—as will usually be the case, given the long
established common-law rule—we presume that Congress
intended the petitioner to bear the burden of proving the
defense of duress by a preponderance of the evidence.
Accordingly, the judgment of the Court of Appeals is
affirmed.
It is so ordered.
Justice Kennedy, concurring.
No one disputes that, subject to constitutional constraints,
Congress has the authority to determine the content of a
duress defense with respect to federal crimes and to direct
whether the burden of proof rests with the defense or the
prosecution. The question here is how to proceed when
Congress has enacted a criminal statute, the Omnibus Crime
Control and Safe Streets Act of 1968, 82 Stat. 197 et seq.
(hereinafter Safe Streets Act), without explicit instructions
regarding the duress defense or its burden of proof. See
ante, at 12–13.
When issues of congressional intent with respect to the
nature, extent, and definition of federal crimes arise, we
assume Congress acted against certain background un
derstandings set forth in judicial decisions in the Anglo-
American legal tradition. See United States v. Bailey, 444
U. S. 394, 415, n. 11 (1980). Those decisions, in turn, consult
sources such as legal treatises and the American Legal Insti

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18 DIXON v. UNITED STATES
Kennedy, J., concurring
tute’s Model Penal Code. See, e. g., United States v. Jime
nez Recio, 537 U. S. 270, 275–276 (2003); Salinas v. United
States, 522 U. S. 52, 64–65 (1997). All of these sources rely
upon the insight gained over time as the legal process contin
ues. Absent some contrary indication in the statute, we can
assume that Congress would not want to foreclose the courts
from consulting these newer sources and considering innova
tive arguments in resolving issues not confronted in the stat
ute and not within the likely purview of Congress when it
enacted the criminal prohibition applicable in the particular
case.
While the Court looks to the state of the law at the time
the statute was enacted, see ante, at 14, the better reading
of the Court’s opinion is that isolated authorities or writings
do not control unless they were indicative of guiding princi
ples upon which Congress likely would have relied. Other
wise, it seems altogether a fiction to attribute to Congress
any intent one way or the other in assigning the burden of
proof. It seems unlikely, moreover, that Congress would
have wanted the burden of proof for duress to vary from
statute to statute depending upon the date of enactment.
Consistent with these propositions, the Court looks not only
to our precedents and common-law traditions, but also to the
treatment of the insanity defense in a 1984 statute and a
proposal of the National Commission on Reform of Federal
Criminal Laws, even though they both postdated the passage
of the Safe Streets Act. See ante, at 12, 15.
As there is no reason to suppose that Congress wanted to
depart from the traditional principles for allocating the bur
den of proof, the proper approach is simply to apply these
principles to the context of duress. See, e. g., Schaffer v.
Weast, 546 U. S. 49, 56 (2005) (where the plain text of the
statute is “silent on the allocation of the burden of persua
sion,” we proceed to consider the “ordinary default rule” and
its exceptions). The facts needed to prove or disprove the
defense “lie peculiarly in the knowledge of ” the defendant.

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19 Cite as: 548 U. S. 1 (2006)
Alito, J., concurring
2 K. Broun, McCormick on Evidence § 337, p. 475 (6th ed.
2006); see ante, at 8–9. The claim of duress in most in
stances depends upon conduct that takes place before the
criminal act; and, as the person who allegedly coerced the
defendant is often unwilling to come forward and testify,
the prosecution may be without any practical means of dis
proving the defendant’s allegations. There is good reason,
then, to maintain the usual rule of placing the burden of pro
duction and persuasion together on the party raising the
issue. See 2 Broun, supra, § 337; ante, at 8. The analysis
may come to a different result, of course, for other defenses.
With these observations, I join the Court’s opinion.
Justice Alito, with whom Justice Scalia joins,
concurring.
I join the opinion of the Court with the understanding that
it does not hold that the allocation of the burden of persua
sion on the defense of duress may vary from one federal
criminal statute to another.
Duress was an established defense at common law. See 4
W. Blackstone, Commentaries on the Laws of England 30
(1769). When Congress began to enact federal criminal
statutes, it presumptively intended for those offenses to be
subject to this defense. Moreover, Congress presumptively
intended for the burdens of production and persuasion to be
placed, as they were at common law, on the defendant. Al
though Congress is certainly free to alter this pattern and
place one or both burdens on the prosecution, either for all
or selected federal crimes, Congress has not done so but in
stead has continued to revise the federal criminal laws and
to create new federal crimes without addressing the issue of
duress. Under these circumstances, I believe that the bur
dens remain where they were when Congress began enacting
federal criminal statutes.
I do not assume that Congress makes a new, implicit judg
ment about the allocation of these burdens whenever it cre

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20 DIXON v. UNITED STATES
Breyer, J., dissenting
ates a new federal crime or, for that matter, whenever it
substantially revises an existing criminal statute. It is un
realistic to assume that on every such occasion Congress sur
veys the allocation of the burdens of proof on duress under
the existing federal case law and under the law of the States
and tacitly adopts whatever the predominant position hap
pens to be at the time. Such a methodology would create
serious problems for the district courts and the courts of
appeals when they are required to decide where the burden
of persuasion should be allocated for federal crimes enacted
on different dates. If the allocation differed for different
offenses, there might be federal criminal cases in which the
trial judge would be forced to instruct the jury that the de
fendant bears the burden of persuasion on this defense for
some of the offenses charged in the indictment and that the
prosecution bears the burden on others.
I would also not assume, as Justice Breyer does, see
post, at 22 (dissenting opinion), that Congress has implicitly
delegated to the federal courts the task of deciding in the
manner of a common-law court where the burden of persua
sion should be allocated. The allocation of this burden is a
debatable policy question with an important empirical com
ponent. In the absence of specific direction from Congress,
cf. Fed. Rule Evid. 501, I would not assume that Congress
has conferred this authority on the Judiciary.
Justice Breyer, with whom Justice Souter joins,
dissenting.
Courts have long recognized that “duress” constitutes a
defense to a criminal charge. Historically, that defense “ex
cuse[d] criminal conduct” if (1) a “threat of imminent death
or serious bodily injury” led the defendant to commit the
crime, (2) the defendant had no reasonable, legal alternative
to breaking the law, and (3) the defendant was not responsi
ble for creating the threat. United States v. Bailey, 444
U. S. 394, 409–410 (1980); see also 2 W. LaFave, Substantive

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21 Cite as: 548 U. S. 1 (2006)
Breyer, J., dissenting
Criminal Law § 9.7(b), pp. 74–82 (2003) (hereinafter LaFave);
ante, at 4, n. 1 (opinion of the Court). The Court decides
today in respect to federal crimes that the defense must bear
the burden of both producing evidence of duress and per
suading the jury. I agree with the majority that the burden
of production lies on the defendant, that here the burden of
persuasion issue is not constitutional, and that Congress may
allocate that burden as it sees fit. But I also believe that,
in the absence of any indication of a different congressional
intent, the burden of persuading the jury beyond a reason
able doubt should lie where such burdens normally lie in
criminal cases, upon the prosecution.
I
My disagreement with the majority in part reflects my
different view about how we should determine the relevant
congressional intent. Where Congress speaks about bur
dens of proof, we must, of course, follow what it says. But
suppose, as is normally the case, that the relevant federal
statute is silent. The majority proceeds on the assumption
that Congress wished courts to fill the gap by examining
judicial practice at the time that Congress enacted the partic
ular criminal statute in question. Ante, at 12–16. I would
not follow that approach.
To believe Congress intended the placement of such bur
dens to vary from statute to statute and time to time is both
unrealistic and risks unnecessary complexity, jury confusion,
and unfairness. It is unrealistic because the silence could
well mean only that Congress did not specifically consider
the “burden of persuasion” in respect to a duress defense.
It simply did not think about that secondary matter. Had
it done so, would Congress have wanted courts to freeze cur
rent practice statute by statute? Would it have wanted to
impose different burden-of-proof requirements where claims
of duress are identical, where statutes are similar, where the
only relevant difference is the time of enactment? Why?

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22 DIXON v. UNITED STATES
Breyer, J., dissenting
Indeed, individual instances of criminal conduct often violate
several statutes. In a trial for those violations, is the judge
to instruct the jury to apply different standards of proof to
a duress defense depending upon when Congress enacted the
particular statute in question? What if in this very case the
defendant’s boyfriend had given her drug money and insisted
(under threat of death) not only that she use some of the
money to buy him a gun, but that she launder the rest? See
18 U. S. C. § 1956 (2000 ed. and Supp. II); see infra, at 25–27.
I would assume instead that Congress’ silence typically
means that Congress expected the courts to develop burden
rules governing affirmative defenses as they have done
in the past, by beginning with the common law and taking
full account of the subsequent need for that law to evolve
through judicial practice informed by reason and experience.
See Davis v. United States, 160 U. S. 469 (1895); McNabb v.
United States, 318 U. S. 332, 341 (1943); ante, at 14, n. 8 (opin
ion of the Court) (proposed general revision of the federal
criminal code would have instructed courts to determine the
contours of affirmative defenses “ ‘according to the principles
of the common law as they may be interpreted in the light
of reason and experience’ ”); 9 J. Wigmore, Evidence § 2486,
p. 291 (J. Chadbourn rev. ed. 1981) (allocation of the burdens
of proof present courts with questions “of policy and fairness
based on experience in the different situations”). That ap
proach would produce uniform federal practice across differ
ent affirmative defenses, as well as across statutes passed at
different points in time.
II
My approach leads me to conclude that in federal criminal
cases, the prosecution should bear the duress defense burden
of persuasion. The issue is a close one. In Blackstone’s
time the accused bore the burden of proof for all affirmative
defenses. See 4 W. Blackstone, Commentaries *201; Patter
son v. New York, 432 U. S. 197, 201–202 (1977). And 20th
century experts have taken different positions on the matter.

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Cite as: 548 U. S. 1 (2006) 23
Breyer, J., dissenting
The Model Penal Code, for example, recommends placing the
burden of persuasion on the prosecution. ALI, Model Penal
Code § 1.12, p. 16, § 1.13(9)(c), p. 18, § 2.09, pp. 37–38 (1985).
The Brown Commission recommends placing it upon the de
fendant. 1 National Commission on Reform of Federal
Criminal Laws, Working Papers 278 (1970). And the pro
posed revision of the federal criminal code, agnostically,
would have turned the matter over to the courts for decision.
S. 1722, 96th Cong., 1st Sess., § 501 (1979). Moreover, there
is a practical argument that favors the Government’s posi
tion here, namely, that defendants should bear the burden of
persuasion because defendants often have superior access to
the relevant proof.
Nonetheless, several factors favor placing the burden on
the prosecution. For one thing, in certain respects the
question of duress resembles that of mens rea, an issue that
is always for the prosecution to prove beyond a reasonable
doubt. See In re Winship, 397 U. S. 358, 364 (1970); Martin
v. Ohio, 480 U. S. 228, 234 (1987). The questions are not the
same. The defendant’s criminal activity here was voluntary;
no external principle, such as the wind, propelled her when
she acted. The Nicomachean Ethics of Aristotle, p. 54
(R. Browne transl. 1865). Moreover, her actions were inten
tional. Whether she wanted to buy the guns or not, and
whether she wanted to lie while doing so or not, she decided
to do these things and knew that she was doing them. In
deed, her action was willful in the sense that she knew that
to do them was to break the law. Ante, at 5–7 (opinion of
the Court); see also Ratzlaf v. United States, 510 U. S. 135,
136–137 (1994).
Nonetheless, where a defendant acts under duress, she
lacks any semblance of a meaningful choice. In that sense
her choice is not free. As Blackstone wrote, the criminal
law punishes “abuse[s] of th[e] free will”; hence “it is highly
just and equitable that a man should be excused for those
acts, which are done through unavoidable force and compul

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24 DIXON v. UNITED STATES
Breyer, J., dissenting
sion.” 4 Commentaries *27. And it is in this “force and
compulsion,” acting upon the will, that the resemblance to
lack of mens rea lies. Cf. Austin, Ifs and Cans, in Proceed
ings of the British Academy 123–124 (1956) (noting difference
between choosing to do something where one has the oppor
tunity and ability to do otherwise and choosing to do some
thing where one lacks any such opportunity or ability).
Davis v. United States, supra, allocated the federal insanity
defense burden to the Government partly for these reasons.
That case, read in light of Leland v. Oregon, 343 U. S. 790,
797 (1952), suggests that, even if insanity does not always
show the absence of mens rea, it does show the absence of
a “ ‘vicious will.’ ” Davis, supra, at 484 (citing Blackstone;
emphasis added).
For another thing, federal courts (as a matter of statu
tory construction or supervisory power) have imposed the
federal-crime burden of persuasion upon the prosecution
in respect to self-defense, insanity, and entrapment, which
resemble the duress defense in certain relevant ways. In
respect to both duress and self-defense, for example, the
defendant’s illegal act is voluntary, indeed, intentional; but
the circumstances deprive the defendant of any meaningful
ability or opportunity to act otherwise, depriving the defend
ant of a choice that is free. Insanity, as I said, may involve
circumstances that resemble, but are not identical to, a lack
of mens rea. And entrapment requires the prosecution to
prove that the defendant was “predisposed” to commit the
crime—a matter sometimes best known to the defendant.
As to self-defense, see First Circuit Pattern Criminal Jury
Instructions § 5.04 (1998); United States v. Thomas, 34 F. 3d
44, 47 (CA2 1994); Government of Virgin Islands v. Smith,
949 F. 2d 677, 680 (CA3 1991); United States v. Harris,
Nos. 95–5637, 95–5638, 1996 U. S. App. LEXIS 22040, *4–*5
(CA4, Aug. 27, 1996); United States v. Branch, 91 F. 3d 699,
714, n. 1 (CA5 1996); Sixth Circuit Pattern Criminal Jury
Instructions § 6.06 (2005); United States v. Jackson, 569 F. 2d

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25 Cite as: 548 U. S. 1 (2006)
Breyer, J., dissenting
1003, 1008, n. 12 (CA7 1978); United States v. Pierre, 254
F. 3d 872, 876 (CA9 2001); United States v. Corrigan, 548
F. 2d 879, 883 (CA10 1977); United States v. Alvarez, 755
F. 2d 830, 842 (CA11 1985); Bynum v. United States, 408 F. 2d
1207 (CADC 1968); see also Mullaney v. Wilbur, 421 U. S.
684, 702, n. 30 (1975) (noting this as the “ ‘majority rule’ ”).
As to insanity, see Davis, 160 U. S., at 486; Leland, supra,
at 797 (making clear that Davis determined burden alloca
tions as a matter of federal, but not constitutional, law); but
see 18 U. S. C. § 17(b) (overruling this default rule to place
the burden on the defendant by clear and convincing evi
dence). As to entrapment, see Jacobson v. United States,
503 U. S. 540, 554 (1992) (reversing the judgment affirming
the conviction because “the prosecution failed, as a matter
of law, to adduce evidence to support the jury verdict that
petitioner was predisposed, independent of the Government’s
acts and beyond a reasonable doubt,” to commit the crime).
See also Patterson, 432 U. S., at 202 (noting that Davis “had
wide impact on the practice in the federal courts with re
spect to the burden of proving various affirmative de
fenses”); Patterson, supra, at 231 (Powell, J., dissenting)
(“[S]ince this Court’s decision in Davis . . . federal prosecu
tors have borne the burden of persuasion with respect to
factors like insanity, self-defense, and malice or provocation,
once the defendant has carried this burden of production”).
Further, most federal courts, in respect to most federal
crimes, have imposed the burden of persuasion in respect to
the duress defense upon the Government, following Johnson
v. United States, 291 F. 2d 150, 155 (CA8 1961), and authori
ties such as E. Devitt & C. Blackmar, Federal Jury Practice
and Instructions § 13.14, p. 293 (2d ed. 1970), and the Federal
Judicial Center Pattern Criminal Jury Instructions § 56
(1988). By the mid-1990’s, seven Circuits had squarely
placed the burden of persuasion upon the prosecution; one
Circuit (the Fifth) placed the burden on the defendant; and
four (the Third, Fourth, Eleventh, and District of Columbia)

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26 DIXON v. UNITED STATES
Breyer, J., dissenting
did not, as far as I can tell, have a definitive practice. Com
pare United States v. Arthurs, 73 F. 3d 444, 448 (CA1 1996);
United States v. Mitchell, 725 F. 2d 832, 836 (CA2 1983);
United States v. Campbell, 675 F. 2d 815, 821 (CA6 1982);
United States v. Talbott, 78 F. 3d 1183, 1186 (CA7 1996) (per
curiam); United States v. Campbell, 609 F. 2d 922, 925 (CA8
1979); United States v. Hearst, 563 F. 2d 1331, 1336, and n. 2
(CA9 1977) (per curiam); and United States v. Falcon, 766
F. 2d 1469, 1477 (CA10 1985), with United States v. Willis,
38 F. 3d 170, 179 (CA5 1994) (putting the burden on the de
fendant by a preponderance). Compare also First Circuit
Pattern Criminal Jury Instructions § 5.05 (1998); Sixth Cir
cuit Pattern Criminal Jury Instructions § 6.05 (1991); Sev
enth Circuit Pattern Criminal Federal Jury Instructions
§ 6.08 (1998); and Eighth Circuit Pattern Criminal Jury In
structions §§ 3.09, 9.02 (2000), with Fifth Circuit Pattern
Criminal Jury Instructions § 1.36 (2001). Petitioner adds,
without contradiction, that the States allocate the burden
similarly by a ratio of 2 to 1. Brief for Petitioner 32–34;
Brief for United States 38, n. 30.
Beginning in 1991, the matter became more complicated
because the Ninth Circuit began to require the defendant to
bear the burden of proving duress in certain circumstances.
United States v. Dominguez-Mestas, 929 F. 2d 1379, 1382,
1384 (per curiam). And a few years later the Third, Sixth,
and Eleventh Circuits followed suit in cases concerning a
closely related justification defense. See United States v.
Dodd, 225 F. 3d 340, 347–350 (CA3 2000); United States v.
Brown, 367 F. 3d 549, 555–556 (CA6 2004); United States v.
Deleveaux, 205 F. 3d 1292, 1298–1300 (CA11 2000); Eleventh
Circuit Pattern Criminal Jury Instructions § 16 (2003). But
see Sixth Circuit Pattern Criminal Jury Instructions § 6.05
(2005) (stating that the burden-of-proof issue for duress is
undecided in that Circuit).
These latter cases, however, put the burden on the defend
ant only where the criminal statute narrows its mens rea

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27 Cite as: 548 U. S. 1 (2006)
Breyer, J., dissenting
requirement, i. e., the burden is the defendant’s where the
statute requires that the defendant act with “knowledge”
but not, suggest these courts, where the statute requires
that the defendant act “willfully,” “intentionally,” or “volun
tarily.” See, e. g., Dominguez-Mestas, supra, at 1382, 1384;
United States v. Meraz-Solomon, 3 F. 3d 298, 300 (CA9 1993)
(per curiam); Ninth Circuit Pattern Criminal Jury Instruc
tions §§ 6.5, 6.6 (2003); but see United States v. Fei Lin, 139
F. 3d 1303, 1307–1308 (CA9 1998). See also Eleventh Circuit
Pattern Criminal Jury Instructions § 16 (2003); United States
v. Diaz, 285 F. 3d 92, 97 (CA1 2002) (indicating that this bi
furcated rule might be appropriate, but noting Circuit prece
dent to the contrary). Similarly, the Tenth Circuit placed
the burden of proving duress upon the defendant in “strict
liability” cases where mens rea is not an element of the crime
at all. United States v. Unser, 165 F. 3d 755, 763–765 (1999).
The apparent upshot is that four Circuits now place the
burden of persuasion on the prosecution across the board;
one places the burden on the prosecution if the statute re
quires mens rea but not otherwise; and four have held or
suggested that the burden should be on the prosecution if
the statute requires an intentional or willful state of mind,
but not if the statute requires only knowledge. While the
Circuits are divided, apparently only one (the Fifth) agrees
with the position taken by the Court today.
Further, while I concede the logic of the Government’s
practical argument—that defendants have superior access
to the evidence—I remain uncertain of the argument’s
strength. After all, “[i]n every criminal case the defendant
has at least an equal familiarity with the facts and in most a
greater familiarity with them than the prosecution.” Tot v.
United States, 319 U. S. 463, 469 (1943). And the strict con
tours of the duress defense, as well as the defendant’s burden
of production, already substantially narrow the circum
stances under which the defense may be used. A defendant
may find it difficult, for example, to show duress where the

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28 DIXON v. UNITED STATES
Breyer, J., dissenting
relevant conduct took place too long before the criminal act.
Cf. ante, at 18–19 (Kennedy, J., concurring). That is be
cause the defendant must show that he had no alternative to
breaking the law. Supra, at 20–21. And that will be the
more difficult to show the more remote the threat. See also
LaFave § 9.7, at 77–79 (duress generally requires an “imme
diate” or “imminent” threat, that the defendant “take advan
tage of a reasonable opportunity to escape,” and that the
defendant “terminate his conduct ‘as soon as the claimed
duress . . . had lost its coercive force’ ”). More important,
the need to prove mens rea can easily present precisely the
same practical difficulties of proof for the prosecutor. Sup
pose for example the defendant claims that an old lady told
him that the white powder he transported across the border
was medicine for her dying son. Cf. United States v. Mares,
441 F. 3d 1152 (CA10 2006). See also Mullaney v. Wilbur,
421 U. S., at 702 (requiring the government to prove an ab
sence of passion in a murder conviction imposes “no unique
hardship on the prosecution”).
It is particularly difficult to see a practical distinction be
tween this affirmative defense and, say, self-defense. The
Government says that the prosecution may “be unable to call
the witness most likely to have information bearing on the
point,” namely, the defendant. Brief for United States 21.
But what is the difference in this respect between the de
fendant here, who says her boyfriend threatened to kill her,
and a battered woman who says that she killed her husband
in self-defense, where the husband’s evidence is certainly un
available? See also Jacobson, 503 U. S. 540 (entrapment;
need to prove “propensity”). Regardless, unless the defend
ant testifies, it could prove difficult to satisfy the defendant’s
burden of production; and, of course, once the defendant tes
tifies, cross-examination is possible.
In a word, I cannot evaluate the claim of practicality with
out somewhat more systematic evidence of the existence of
a problem, say, in those Circuits that for many years have

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29 Cite as: 548 U. S. 1 (2006)
Breyer, J., dissenting
imposed the burden on the prosecutor. And, of course, if I
am wrong about the Government’s practical need (and were
my views to prevail), the Government would remain free to
ask Congress to reallocate the burden.
Finally, there is a virtue in uniformity, in treating the fed
eral statutory burden of persuasion similarly in respect to
actus reus, mens rea, mistake, self-defense, entrapment, and
duress. The Second Circuit, when imposing the burden of
persuasion for duress on the prosecution, wrote that differ
ences in this respect create “a grave possibility of juror con
fusion.” United States v. Mitchell, 725 F. 2d 832, 836 (1983)
(Newman, J., joined by Feinberg, C. J., and Friendly, J.).
They risk unfairness as well.
For these reasons I believe that, in the absence of an indi
cation of congressional intent to the contrary, federal crimi
nal law should place the burden of persuasion in respect to
the duress defense upon the prosecution, which, as is now
common in respect to many affirmative defenses, it must
prove beyond a reasonable doubt. With respect, I dissent.