(Slip Opinion) OCTOBER TERM, 2023 1 

Syllabus 

NOTE: Where it is feasible, a syllabus (headnote) will be released, as is 

being done in connection with this case, at the time the opinion is issued. 

The syllabus constitutes no part of the opinion of the Court but has been 

prepared by the Reporter of Decisions for the convenience of the reader. 

See United States v. Detroit Timber & Lumber Co., 200 U. S. 321, 337. 

SUPREME COURT OF THE UNITED STATES 

Syllabus 

BROWN v. UNITED STATES 

CERTIORARI TO THE UNITED STATES COURT OF APPEALS FOR 

THE THIRD CIRCUIT 

No. 22–6389. Argued November 27, 2023—Decided May 23, 2024* 

These cases concern the application of the Armed Career Criminal Act to

state drug convictions that occurred before recent technical amendments to the federal drug schedules. ACCA imposes a 15-year mandatory minimum sentence on defendants who are convicted for the illegal 

possession of a firearm and who have a criminal history thought to 

demonstrate a propensity for violence. As relevant here, a defendant 

with “three previous convictions” for “a serious drug offense” qualifies 

for ACCA’s enhanced sentencing. 18 U. S. C. §924(e)(1). For a state 

crime to qualify as a “serious drug offense,” it must carry a maximum

sentence of at least 10 years’ imprisonment, and it must “involv[e] . . . 

a controlled substance . . . as defined in section 102 of the Controlled 

Substances Act.” §§924(e)(1), (2)(A)(ii). 

Under the categorical approach, a state drug offense counts as an 

ACCA predicate only if the State’s definition of the drug in question

“matche[s]” the definition under federal law. Shular v. United States, 

589 U. S. 154, 158. The question presented is whether a state crime 

constitutes a “serious drug offense” if it involved a drug that was on 

the federal schedules when the defendant possessed or trafficked in it 

but was later removed. 

Petitioners Justin Rashaad Brown and Eugene Jackson were separately convicted of the federal crime of possession of a firearm by a 

convicted felon in violation of §922(g)(1). In both cases, an ACCA enhancement was recommended based on prior state felony drug convictions. And both defendants argued that their prior convictions did not 

qualify as “serious drug offense[ s].” 

—————— 

*Together with No. 22–6640, Jackson v. United States, on certiorari to 

the United States Court of Appeals for the Eleventh Circuit. 
 

 

 

 

 

2 BROWN v. UNITED STATES 

Syllabus 

Brown’s presentence report identified several Pennsylvania drug

convictions, including four convictions for possessing marijuana with 

intent to distribute. At the time of Brown’s marijuana convictions, the 

federal and Pennsylvania law definitions of marijuana matched. But 

while Brown’s federal §922(g)(1) charge was pending, Congress modified the federal definition of marijuana. Because the federal and state 

definitions did not fully match when Brown was sentenced, Brown argued that his marijuana convictions no longer qualified as “serious

drug offense[s]” for purposes of the ACCA sentencing enhancement. 

Jackson’s presentence report identified several prior Florida convictions, including convictions in 1998 and 2004 for possession and distribution of cocaine. In 2015, the Federal Government amended the federal definition of cocaine, so the federal and Florida definitions no 

longer matched when Jackson committed his §922(g)(1) offense. Like 

Brown, Jackson argued that these prior convictions no longer qualified 

as “serious drug offense[s].” In both cases, the District Courts disagreed and sentenced petitioners to enhanced sentences, and the respective appellate courts ultimately affirmed. 

Held: A state drug conviction counts as an ACCA predicate if it involved

a drug on the federal schedules at the time of that offense. Pp. 4– 

19. 

(a) The parties propose three different answers to the question

whether the federal and state definitions of a drug must match when 

the state crime is committed or at some later point in time. The Government argues that a prior state drug conviction qualifies if the federal and state definitions of the relevant drug matched when the defendant committed the state crime. Jackson argues instead that the

definitions must match when the defendant violates the federal felonin-possession statute. Finally, Brown contends that the definitions 

must match when the defendant is sentenced for the federal felon-inpossession offense. Pp. 4–7.

(b) Precedent and statutory context support the Government’s interpretation. ACCA gauges what a defendant’s “history of criminal activity” says about his or her “culpability and dangerousness.” McNeill v. 

United States, 563 U. S. 816, 823. In previous cases, the Court has 

held that ACCA requires sentencing courts to examine the law as it

was when the defendant violated it. This “backward-looking” approach, id., at 820, supports the Government’s interpretation. And the 

plain language of the statute points to the same conclusion. Section 

924(e)(2)(A)(i), which immediately precedes the provision at issue, defines a “serious drug offense” to include, among other things, “offense[s] under the Controlled Substances Act.” A later change in a

federal drug schedule does not change the fact that an offense “under 
 

 

 

 

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Syllabus 

the [CSA]” is a “serious drug offense.” The Government’s interpretation would treat state offenses “involving . . . a controlled substance (as

defined in [the CSA])” like those federal offenses “under the [CSA].” 

Petitioners’ interpretations, by contrast, would treat those federal and 

state offenses differently, i.e., the federal offense would remain an 

ACCA predicate, but the state offense would not. Pp. 7–9. 

(c) The Government’s interpretation also best fulfills ACCA’s statutory objectives. In Congress’s view, defendants who have repeatedly 

committed ACCA predicate offenses are “especially likely to inflict

grave harm when in possession of a firearm,” so ACCA imposes a 

higher punishment when they do so. Wooden v. United States, 595 

U. S. 360, 375. Because a defendant’s “history of criminal activity”

does not “cease to exist” merely because the crime was later redefined, 

McNeill, 563 U. S., at 823, it makes sense to ask whether a prior offense met ACCA’s definition of seriousness at the time it was committed. Brown’s and Jackson’s contrary arguments misunderstand the 

theory on which ACCA is based. A prior drug conviction for an offense 

punishable by 10 years’ imprisonment augurs a risk of future dangerousness even if the drug is no longer considered dangerous. Indeed, in 

McNeill, the Court found “absurd” petitioner’s argument that a later

reduction in the maximum sentence for his offense reflected a legislative judgment that his prior offense was less serious than previously 

thought. Id., at 822. The “subsequent chang[e] in state law” did not

“erase [the] earlier conviction.” Id., at 823. And it was the fact of that 

earlier conviction—not the legislature’s subsequent judgment—that 

ACCA was concerned with, because that fact “demonstrate[d]” the defendant’s “culpability and dangerousness.” Ibid. Pp. 9–12.

(d) Petitioners various other arguments are unpersuasive. Pp. 12– 

19. 

(1) Relying on the so-called reference canon, Jackson claims that 

ACCA “incorporates [the] schedules . . . ‘as [they] exis[t] whenever a 

question under [ACCA] arises.’ ” Brief of Petitioner Jackson 32. The 

reference canon provides that a statutory reference to a “general subject” incorporates “the law on that subject as it exists whenever a question under the statute arises.” Jam v. International Finance Corp., 

586 U. S. 199, 209 (emphasis added). But a reference “to another statute by specific title or section number”—such as ACCA’s reference to

21 U. S. C. §802—“in effect cuts and pastes the referenced statute as 

it existed when the referring statute was enacted.” Ibid. Even assuming that there may be contexts in which references to specific statutory

provisions may be considered general, it is hard to see the phrase “as 

defined in section 102 of the Controlled Substances Act” as anything 

but a specific reference. Jackson’s alternative argument—that his

reading is required by the “settled legal principle” that “the law that 
 

 

 

 

4 BROWN v. UNITED STATES 

Syllabus 

sets the penalty for a federal crime is the law in place when the crime 

was committed”—simply begs the question what §924(e)(2)(a)(ii) 

means. Pp. 12–14.

(2) Brown suggests that present-tense language in ACCA’s definition of a “serious drug crime”—language such as “involving” and “as

defined in”—indicates a present-day focus requiring courts to look to 

the drug schedules in effect at the time of federal sentencing. The 

Court rejected that approach in McNeill, holding that ACCA requires

a historical inquiry into the state law at the time of that prior offense 

and that “[u]se of the present tense . . . did not suggest otherwise.” 563 

U. S., at 820. Brown also claims that his reading is required by United 

States v. Schooner Peggy, 1 Cranch 103, 110, which says that when the 

law changes while a case is in progress, the case must be decided under

the new law. But §924(e)(2)(A)(ii) has not changed at any point in the 

litigation. Pp. 15–17. 

(3) Petitioners’ additional arguments do not persuade. Petitioners 

assert that this Court’s interpretation is underinclusive because it 

would preclude ACCA enhancements for state offenses involving drugs

added to the federal lists only after the state crimes were committed. 

But none of the parties’ interpretations captures all cases involving 

career criminals. Petitioners next suggest that the Government’s interpretation is absurd because it would exclude all state drug convictions before the CSA’s enactment in 1970. But there are reasons Congress might have chosen not to court either federal or state drug 

convictions that occurred before 1970. Petitioners also argue that the 

Government’s interpretation would unduly burden courts and defendants by requiring them to undertake the laborious task of digging up

old federal drug schedules and comparing those to the state laws the

defendants violated, but petitioners overstate the difficulty of this 

task. Finally, petitioners contend that the rule of lenity counsels in 

favor of their interpretations. But lenity applies only if a statute remains grievously ambiguous, and here context, precedent, and statutory design adequately show “ ‘what Congress intended.’ ” United 

States v. Castleman, 572 U. S. 157, 173. Pp 17–19. 

No. 22–6389, 47 F. 4th 147, and No. 22–6640, 55 F. 4th 846, affirmed.

 ALITO, J., delivered the opinion of the Court, in which ROBERTS, C. J., 

and THOMAS, SOTOMAYOR, KAVANAUGH, and BARRETT, JJ., joined. JACKSON, J., filed a dissenting opinion, in which KAGAN, J., joined, and in 

which GORSUCH, J., joined as to Parts I, II, and III. 
 

_________________ 

_________________ 

Cite as: 602 U. S. ____ (2024) 1 

Opinion of the Court 

NOTICE: This opinion is subject to formal revision before publication in the 

United States Reports. Readers are requested to notify the Reporter of 

Decisions, Supreme Court of the United States, Washington, D. C. 20543, 

pio@supremecourt.gov, of any typographical or other formal errors. 

SUPREME COURT OF THE UNITED STATES 

Nos. 22–6389 and 22–6640 

JUSTIN RASHAAD BROWN, PETITIONER 

22–6389 v. 

UNITED STATES 

ON WRIT OF CERTIORARI TO THE UNITED STATES COURT OF 

APPEALS FOR THE THIRD CIRCUIT 

EUGENE JACKSON, PETITIONER 

22–6640 v. 

UNITED STATES 

ON WRIT OF CERTIORARI TO THE UNITED STATES COURT OF 

APPEALS FOR THE ELEVENTH CIRCUIT 

[May 23, 2024] 

JUSTICE ALITO delivered the opinion of the Court. 

These cases concern the application of the Armed Career 

Criminal Act (ACCA) to state drug convictions that occurred before recent technical amendments to the federal 

drug schedules. ACCA imposes a 15-year mandatory minimum sentence on defendants who are convicted for the illegal possession of a firearm and have a criminal history that 

is thought to demonstrate a propensity for violence. These 

defendants are subject to ACCA’s enhanced penalty if,

among other things, they have “three previous convictions”

for “a serious drug offense.” 18 U. S. C. §924(e)(1). For a 

state crime to qualify as a “serious drug offense,” it must 

carry a maximum sentence of at least 10 years’ imprisonment, and it must “involv[e] . . . a controlled substance . . . 

as defined in section 102 of the Controlled Substances Act” 
 

2 BROWN v. UNITED STATES 

Opinion of the Court 

(CSA). §§924(e)(1), (2)(A)(ii). The CSA, in turn, includes 

five schedules of controlled substances and provides that 

these schedules must be updated each year by the Attorney

General. 84 Stat. 1245, 1247, 21 U. S. C. §§811, 812. 

The two cases now before us present the question 

whether a state crime constitutes a “serious drug offense” if 

it involved a drug that was on the federal schedules when 

the defendant possessed or trafficked in it but was later removed. We hold that such an offense qualifies. 

I 

A 

In 2016, Justin Rashaad Brown sold cocaine to police officers in a series of controlled buys. The officers conducted 

two warrant-authorized searches of Brown’s home, where 

they discovered cocaine and a loaded .38-caliber revolver. 

In 2018, a federal grand jury returned an indictment charging Brown with several drug offenses, as well as possession

of a firearm by a convicted felon in violation of 18 U. S. C.

§922(g)(1). Brown pleaded guilty in 2019 and was sentenced two years later. 

At sentencing, the probation office recommended that 

Brown receive ACCA’s mandatory minimum sentence because he had four prior Pennsylvania convictions for possessing marijuana with intent to distribute between 2009 

and 2014, as well as one Pennsylvania conviction for distributing cocaine in 2008. Brown disputed this interpretation of ACCA and argued that his marijuana convictions did 

not “involv[e] . . . a controlled substance . . . as defined in 

[the CSA].” §924(e)(2)(A)(ii). 

A state drug offense counts as an ACCA predicate only if

the State’s definition of the drug in question “matche[s]” the 

definition under federal law. Shular v. United States, 589 

U. S. 154, 158 (2020). When Brown was convicted for possessing marijuana, both federal and Pennsylvania law defined marijuana to include “all parts of the plant Cannabis 
 

Cite as: 602 U. S. ____ (2024) 3 

Opinion of the Court 

sativa L.,” so the definitions were a categorical match. 21 

U. S. C. §802(16) (2006 ed.); Pa. Stat. Ann., Tit. 35, §780–

102(b) (Purdon Cum. Supp. 2012) (defining marijuana to include “all forms, species and/or varieties of the genus Cannabis sativa L.”). But while Brown’s federal charge was 

pending, Congress enacted the Agriculture Improvement 

Act of 2018, which exempted some hemp, a variety of Cannabis sativa L., from the federal definition of marijuana. 

Pub. L. 115–334, §12619(a)(2), 132 Stat. 5018.1 Because the 

federal and state definitions did not fully match when

Brown was sentenced, he argued that his marijuana convictions no longer qualified as “serious drug offense[s].” 

The District Court disagreed and sentenced him under 

ACCA, and the Third Circuit affirmed. It concluded that 

the 2018 amendment did not apply retroactively to federal 

offenses committed before its effective date. Under the 

Third Circuit’s view, Brown was “properly subject to . . . 

ACCA’s enhanced penalties” because he violated §922(g) 

when the federal and state definitions of marijuana were a

categorical match. 47 F. 4th 147, 153, 155 (2022). 

B 

In 2017, Eugene Jackson noticed a police car arriving at 

the Sparkle Food Market to execute an unrelated search 

warrant, and he responded by fleeing and discarding a 

loaded .45-caliber pistol. Officers eventually identified 

Jackson as the gun’s owner, and in 2019, he was charged 

with possession of a firearm by a convicted felon. He 

pleaded guilty and was sentenced in 2021. 

Jackson’s presentence report identified several prior 

Florida convictions as ACCA predicates, including convictions in 1998 and 2004 for possession and distribution of 

—————— 1Hemp is exempted if it contains less than 0.3% THC (tetrahydrocannabinol), the main psychoactive constituent of cannabis. See 7 U. S. C. 

§1639o; 21 U. S. C. §802(16). 
 

 

 

4 BROWN v. UNITED STATES 

Opinion of the Court 

cocaine. But Jackson, like Brown, claimed that these convictions were not for “serious drug offense[s].” When those 

crimes were committed, the Federal Government and Florida defined cocaine the same way. 21 U. S. C. §812(c),

Schedule II, (a)(4); Fla. Stat. §§893.03(2)(a)(4), 893.13(1) 

(1998). But in 2015, the Federal Government legalized a 

radioactive cocaine derivative called [123I]ioflupane that is 

the active pharmaceutical ingredient in a drug used to diagnose patients who are suspected to have Parkinson’s disease. See Schedules of Controlled Substances: Removal of 

[123I]Ioflupane From Schedule II of the Controlled Substances Act, 80 Fed. Reg. 54717. So when Jackson committed his federal offense, the federal and Florida definitions 

were no longer a categorical match.

The District Court found that Jackson’s prior convictions

qualified as serious drug offenses and sentenced him to

ACCA’s mandatory minimum. On appeal, the Eleventh

Circuit initially disagreed and vacated Jackson’s sentence.

36 F. 4th 1294, 1306 (2022). But a few months later, the 

panel sua sponte vacated its opinion, ordered supplemental 

briefing, and in a new opinion affirmed the District Court.

55 F. 4th 846, 862 (2022). The Eleventh Circuit reasoned 

that a prior drug conviction is an ACCA predicate if the 

state and federal definitions of the drug matched when the 

defendant committed the state offense. Id., at 854. 

We granted Brown’s and Jackson’s petitions for a writ of 

certiorari and consolidated the two cases. 598 U. S. ___ 

(2023). We now affirm. 

II 

A 

These cases ask what 18 U. S. C. §924(e)(2) means when

it refers to a prior state drug offense “involving . . . a controlled substance . . . as defined in section 102 of the [CSA],” 

and specifically, whether the federal and state definitions

of a drug must match when the state crime is committed or 
Cite as: 602 U. S. ____ (2024) 5 

Opinion of the Court 

at some later point in time. The parties propose three different answers. 

The Government argues that a prior state drug conviction

qualifies if the federal and state definitions of the relevant 

drug matched when the defendant committed the state 

crime. Therefore, even if the federal and state definitions 

are different when a defendant violates the federal felon-inpossession law or is sentenced under that law, earlier state 

convictions that occurred during the period when the federal and state definitions were the same nevertheless qualify as “serious drug offense[s].”

Jackson, by contrast, argues that the federal and state

definitions must match when the defendant violates the 

federal felon-in-possession statute. In his view, it does not 

matter whether the federal and state laws both criminalized the relevant drug when a defendant possessed or trafficked in it. If the Federal Government later narrows its 

definition of that drug, no state conviction under the

broader definition counts against a defendant who later 

commits the federal firearm offense. 

This interpretation would mean that Jackson’s two cocaine convictions are no longer “serious drug offense[s]” because, years later, the Federal Government narrowed the

definition of cocaine in the federal schedules to legalize a 

Parkinson’s drug derived from cocaine. In fact, under Jackson’s and the dissent’s interpretation, no Florida cocaine 

convictions obtained before July 1, 2017, when Florida also 

legalized the derivative, would count. See 2017 Fla. Laws 

ch. 2017–110. That would be true even for convictions involving the possession or distribution of huge shipments of 

cocaine base.2 And as other courts have noted, cocaine convictions under the laws of many other States would likewise 

—————— 2See, e.g., E. Johnson, A Sarasota Drug Sting Brings Results 10 Arrests, 

and a Million-Dollar Supply of Cocaine Taken Off, Sarasota Herald-Tribune 

(Feb. 4, 2014), https://www.heraldtribune.com/story/news/2014/02/05/asarasota-drug-sting-brings-results-10-arrests-and-a-million-dollar-supply 
 

 

6 BROWN v. UNITED STATES 

Opinion of the Court 

be affected. See, e.g., United States v. Perez, 46 F. 4th 691, 

698–701 (CA8 2022) (excluding an Iowa conviction under 

Jackson’s theory); United States v. Myrick, 2023 WL 

2351693, *2 (ED Pa., Mar. 2, 2023) (excluding a Pennsylvania conviction).

These cocaine convictions would be excluded even though

it is highly unlikely that any were based on the possession

or sale of the Parkinson’s drug. That derivative is radioactive, so it can be produced only through a “highly technical

and complex synthetic route,” and the drug in which it appears can be stored for no more than 24 hours. Dept. of

Justice, Drug Enforcement Admin., Office of Diversion Control, Schedule of Controlled Substances: Removal of [123I]Ioflupane From Schedule II of the Controlled Substances Act:

Background, Data, and Analysis 5–6 (2015). Furthermore, 

anyone attempting to become intoxicated by using the drug

would need to inject “nearly 6,000 vials,” or “15 liters of 

fluid, a volume likely to cause death if administered intravenously.” Id., at 2. Unsurprisingly, the Federal Government has identified “no case reports” involving individuals 

who misused that drug, or any other [123I]ioflupane-containing product. Id., at 6. 

Brown offers a third option. He contends that the federal 

and state definitions must match when the defendant is 

sentenced for the federal firearm offense. Under his interpretation, it does not matter whether the two definitions

matched when a defendant previously violated state law or 

even when he or she committed the federal firearm offense. 

As he sees it, if the federal authorities narrow the definition 

of a drug at any point before sentencing, the prior state convictions no longer count as ACCA predicates. 

This interpretation would produce strange results in 

—————— 

-of-cocaine-taken-off/29227445007; see also Verdict in State v. Gomez, 

No. 2014CF001404–004NC (12th Jud. C. C. Sarasota Cty., Fla., May 1, 

2014). 
 

 

Cite as: 602 U. S. ____ (2024) 7 

Opinion of the Court 

cases involving long criminal investigations or prosecutions. In this case, for example, Congress adopted the partial exemption of hemp nearly nine months after Brown was

indicted, and more than two years after he violated §922(g).

Under his proposed interpretation, he is exempt from

ACCA’s mandatory minimum only because his prosecution 

did not move more quickly.

Indeed, Brown’s interpretation could result in very different sentences for co-defendants who committed the same 

state marijuana offense on the same days and likewise committed the felon-in-possession offense at the same time. 

But see 18 U. S. C. §3553(a)(6) (instructing sentencing 

courts to “avoid unwarranted sentence disparities among 

defendants with similar records who have been found guilty 

of similar conduct”). Under Brown’s interpretation, if one 

co-defendant was sentenced on December 19, 2018, one day 

before the Agriculture Improvement Act was signed into 

law, and the other was sentenced on December 21, the day 

after enactment, ACCA’s 15-year mandatory minimum

would apply to the first but not the second. 

B 

We must decide which of these three proposed interpretations is correct. Standing alone, the operative phrase “involving . . . a controlled substance (as defined in [the CSA])” 

does not definitively answer that question, but precedent 

and statutory context show that the Government’s interpretation is correct. 

ACCA is a recidivist statute that gauges what a defendant’s “history of criminal activity” says about his or her “culpability and dangerousness.” McNeill v. United States, 563 

U. S. 816, 823 (2011). It does this through a “backwardlooking” examination, id., at 820, of “previous convictions” 

that bear on dangerousness, §924(e)(1). Thus, as we explained in McNeill, ACCA requires sentencing courts to examine the law as it was when the defendant violated it, 
 

8 BROWN v. UNITED STATES 

Opinion of the Court 

even if that law is subsequently amended. Id., at 820–822 

(listing cases examining the law at the time of the predicate 

offense).

In McNeill, the question was whether a prior state drug

conviction was for a crime that carried the maximum penalty needed to qualify as a “serious drug offense,” i.e., imprisonment for 10 years or more. To answer that question,

we looked back to “the law under which the defendant was 

convicted” and concluded that a subsequent statutory 

amendment reducing the maximum penalty below the 10-

year threshold did not matter. Id., at 820. This “backwardlooking” approach supports the Government’s interpretation here. 

The plain language of 18 U. S. C. §924(e)(2)(A)(i), the provision that immediately precedes the provision at issue

here, §924(e)(2)(A)(ii), points to the same conclusion. Section 924(e)(2)(A)(i) defines a “serious drug offense” to include certain federal drug crimes, namely, “offense[s] under 

the Controlled Substances Act (21 U. S. C. §801 et seq.)” or 

two other federal laws. (Emphasis added.) Any crime contained in the CSA is an offense “under the [CSA].” The 

standard “Judgment in a Criminal Case” used in federal 

courts indicates whether a defendant was convicted and 

sentenced for such an offense,3 and a later change in a federal drug schedule cannot change that fact. The Government’s interpretation would treat state offenses “involving 

. . . a controlled substance (as defined in [the CSA])” like 

those federal offenses “under the [CSA].” §924(e)(2).

Petitioners’ interpretations, by contrast, would treat

those federal and state offenses differently. Consider a defendant who was caught distributing cocaine on back-toback days, was charged with a federal crime for the first

day’s offense and an identical state crime for the second,

and was convicted of both before the 2015 amendment that 

—————— 3See https://www.uscourts.gov/sites/default/files/ao245b.pdf. 
 

Cite as: 602 U. S. ____ (2024) 9 

Opinion of the Court 

deleted the Parkinson’s drug from the definition of cocaine. 

Under petitioners’ interpretations, the federal offense

would remain an ACCA predicate, but the state offense 

would not, even though the crimes and the statutes of conviction were otherwise identical. 

That is a very strange reading of §§924(e)(2)(A)(i) and (ii).

Both subsections refer to prior offenses relating to the CSA,

and in §924(e)(2)(i) Congress clearly indicated that past 

conduct that violated the CSA is probative of a defendant’s

“culpability and dangerousness,” McNeill, 563 U. S., at 823, 

even if the federal drug schedule is later amended. There 

is no reason to think Congress reached a different judgment 

as to petitioners’ conduct merely because they had been convicted under a state, rather than federal, statute. Indeed, 

it would be unnatural to give back-to-back references to the 

CSA starkly different interpretations. See, e.g., Brown v. 

Gardner, 513 U. S. 115, 118 (1994); Ratzlaf v. United 

States, 510 U. S. 135, 143 (1994).4 

C 

The Government’s interpretation also best fulfills 

ACCA’s statutory objectives. Congress’s “general approach” in ACCA was to single out “offenses of a certain 

level of seriousness that involve violence or an inherent risk 

—————— 4 Jackson argues that reading 18 U. S. C. §924(e)(2) to refer to the past

would be inconsistent with other statutory references to the CSA that 

“must incorporate the CSA schedules at the time of the federal offense.” 

Brief for Petitioner Jackson 14. For example, he points to §924(g)(3), 

which criminalizes cross-border travel to obtain a firearm intended for 

use in a state offense “relating to any controlled substance (as defined in

[the CSA]),” and §342, which prohibits the operator of a common carrier

from operating under the influence of “any controlled substance (as defined in [the CSA]).” But those statutes focus entirely on present-day 

conduct, while ACCA refers to “previous convictions.” §924(e)(1). Because ACCA is concerned with recidivism, it is not inconsistent to read 

it differently. 
 

 

10 BROWN v. UNITED STATES 

Opinion of the Court 

thereof, and that are likely to be committed by career offenders.” Taylor v. United States, 495 U. S. 575, 590 (1990). 

Because defendants who have repeatedly committed ACCA

predicate offenses are “especially likely to inflict grave

harm when in possession of a firearm,” ACCA imposes a 

higher punishment when they do so. Wooden v. United 

States, 595 U. S. 360, 375 (2022); United States v. Rodriquez, 553 U. S. 377, 385 (2008) (“[A] second or subsequent 

offense is often regarded as more serious because it portends greater future danger and therefore warrants an increased sentence for purposes of deterrence and incapacitation”). A defendant’s “history of criminal activity” does not

“cease to exist” merely because the crime was later redefined. McNeill, 563 U. S., at 823. It therefore makes sense 

to ask, as the Government does, whether a prior offense met 

ACCA’s definition of seriousness—and thus suggested future danger—at the time it was committed. 

Petitioners and the dissent disagree. As Brown puts

it, when the Federal Government “changes the federal 

drug schedules,” it “necessarily conclude[s]” that the 

de-scheduled substance “does not implicate the culpability 

or harm that federal law previously attributed to it.” Reply

Brief for Petitioner Brown 1 (emphasis deleted). Of course, 

Brown and Jackson were themselves convicted of crimes involving substances that are still on the federal schedules, 

marijuana and cocaine, not hemp or [123I]ioflupane.5 But 

even setting that aside, their argument misunderstands the 

theory on which ACCA is based.

A prior drug conviction for an offense punishable by 10

years’ imprisonment augurs a risk of future dangerousness 

—————— 5Latching onto this sentence, the dissent spends three pages accusing

us of departing from the categorical approach. Post, at 11–14 (opinion of 

JACKSON, J.). The dissent attacks a strawman. We agree that our precedents require us to ask whether a defendant’s prior conviction matches

ACCA’s requirements. Post, at 11–12. The question here is what ACCA 

requires. 
Cite as: 602 U. S. ____ (2024) 11 

Opinion of the Court 

even if the drug is no longer considered dangerous. That is 

because the conviction reveals that the defendant previously engaged in illegal conduct that created a dangerous

risk of violence, either with law enforcement or with others 

operating in the same illegal field. If left at large, such defendants present a serious risk to public safety. 

That risk “does not cease to exist” if the law under which 

the defendant was convicted is later amended or eliminated. McNeill, 563 U. S., at 823. For example, consider a

person who distributed alcohol during Prohibition. The 

later legalization of alcohol did not by any means ensure 

that these bootleggers would take up legitimate jobs. Instead, after the end of Prohibition, many of them simply 

shifted to other illegal enterprises. See S. Morison, The Oxford History of the American People 901 (1965) (Prohibition

led to “the building up of a criminal class that turned to

gambling and drugs” after the Eighteenth Amendment was 

repealed). Likewise, Brown’s and Jackson’s multiple convictions for serious drug crimes are evidence that they may

continue to “‘commit a large number of fairly serious crimes 

as their means of livelihood’” in the future. Wooden, 595 

U. S., at 375 (quoting Taylor, 495 U. S., at 587). And that 

risk remains true despite the technical changes to the federal drug schedules on which their arguments hang. 

For this reason, the Court has previously rejected similar 

arguments about ACCA’s rationale. Like petitioners here, 

the petitioner in McNeill argued that a later reduction in 

the maximum sentence for his offense reflected a legislative 

judgment that his prior offense was less serious than previously thought. Brief for Petitioner in No. 10–5258 (CA4), 

pp. 15, 35. And this, he suggested, meant that the offense

should no longer be treated as “serious” under ACCA. We 

termed that argument “absurd.” McNeill, 563 U. S., at 822. 

The “subsequent chang[e] in state law” did not “erase [the]

earlier conviction.” Id., at 823. And it was the fact of that 
 

 

12 BROWN v. UNITED STATES 

Opinion of the Court 

earlier conviction—not the legislature’s subsequent judgment—that ACCA was concerned with, because that fact 

“demonstrate[d]” the defendant’s “culpability and dangerousness.” Ibid. 

III 

Petitioners and the dissent make various other arguments, but none is persuasive. 

A 

1 

Jackson mainly relies on two interpretive tools. He begins with the so-called reference canon. Brief for Petitioner 

Jackson 31. This canon, he claims, means that ACCA “incorporates [the] schedules . . . ‘as [they] exis[t] whenever a

question under [ACCA] arises.’” Id., at 32 (quoting Jam v. 

International Finance Corp., 586 U. S. 199, 209 (2019)).

“And,” he says, “the first time a ‘question arises’ under 

ACCA is when a person commits [a] federal firearm offense.” Brief for Petitioner Jackson 32. 

The reference canon can be a helpful tool, but Jackson

misuses it. That canon provides that a statutory reference 

to a “general subject” incorporates “the law on that subject

as it exists whenever a question under the statute arises.” 

Jam, 586 U. S., at 209 (emphasis added). But a reference 

“to another statute by specific title or section number”—

such as ACCA’s reference to 21 U. S. C. §802—“in effect 

cuts and pastes the referenced statute as it existed when

the referring statute was enacted, without any subsequent 

amendments.” 586 U. S., at 209–210 (emphasis added). 

That part of the reference canon undermines Jackson’s position. 

Jackson attempts to rescue his argument by asserting 

that ACCA’s mention of the CSA is actually a “general reference.” Reply Brief for Petitioner Jackson 15. To support

this argument, he cites cases that treat statutes as adopting 
 

 

Cite as: 602 U. S. ____ (2024) 13 

Opinion of the Court 

“the general law on [a] subject,” even though the statutes

“referred to” that general law “in terms of the sections of 

the statutes in which it is to be found.” George Williams 

College v. Williams Bay, 242 Wis. 311, 316, 317, 7 N. W. 2d 

891, 894 (1943). But even if we assume that there may be 

contexts in which references to specific statutory provisions

may be considered “general,” see, e.g., Matter of Commitment of Edward S., 118 N. J. 118, 134, n. 9, 570 A. 2d 917, 

925, n. 9 (1990), it is hard to see the phrase “as defined in 

section 102 of the Controlled Substances Act” as anything 

but a specific reference. 18 U. S. C. §924(e)(2)(A)(ii). 

And for reasons already set out, the “context” here does 

not help Jackson. As we have explained, his reading would 

treat a state offense involving a “controlled substance . . . 

defined in [the CSA]” differently from a federal offense “under the [CSA],” even though both phrases make reference 

to the same Act. Supra, at 8–9. That approach would give

defendants with prior state offenses the benefit of subsequent amendments to the CSA but would ignore those same

amendments for prior federal offenses. In that context, 

Jackson’s reliance on the reference canon is clearly unpersuasive. 

Alternatively, Jackson says that his reading is required 

by the “settled legal principle” that “the law that sets the

penalty for a federal crime is the law in place when the

crime was committed.” Brief for Petitioner Jackson 17 (citing Dorsey v. United States, 567 U. S. 260, 272–273 (2012)). 

And to show that this principle supports his reading of

§924(e)(2)(A)(ii), he offers a series of hypotheticals involving 

amendments to ACCA. Brief for Petitioner Jackson 18–20. 

Here is one. If Congress deleted drug possession from the 

list of “serious drug offense[s],” he argues, no one would

think that someone who “commit[ted] a federal firearm offense after this change . . . would be subject to ACCA based 

on a prior state conviction” for drug possession. Id., at 18. 

Therefore, he maintains, the same should be true for 
 

14 BROWN v. UNITED STATES 

Opinion of the Court 

amendments to the schedules. 

This argument begs the question that these cases present, which is whether §924(e)(2)(A)(ii) is amended with 

every change in the drug schedules. Jackson imagines a 

version of ACCA that plainly would not apply to a prior 

state offense because that version would no longer list drug 

possession as a “serious” offense, and he then reasons that 

the same result should obtain here. But in his hypothetical, 

§924(e) was amended. Here, only the federal drug schedules were changed. Jackson’s argument that a change in

the federal drug schedules equates to a change in

§924(e)(2)(A)(ii) is thus nothing more than his referencecanon argument dressed in different garb. And for the reasons we have explained, we are convinced that the canon 

does not work in the way he suggests.

In all events, Jackson’s emphasis on “the law in place

when the crime was committed” is a red herring. Section 

924(e)(2)(A)(ii) currently means that a prior state drug conviction may constitute an ACCA predicate if the drugs on 

the federal and state schedules matched when the state 

drug offense was committed. Thus, contrary to Jackson’s 

suggestion, treating his prior convictions as ACCA predicates is entirely consistent with the “settled legal principle” 

that current law “sets the penalty for a federal crime.” Id., 

at 17. 

2 

The dissent agrees with Jackson’s interpretation but for

a different reason. It believes that all cross-references 

“plug [in] the referenced provision” as it exists “at the time 

of the statute’s interpretation.” Post, at 4–5 (opinion of 

JACKSON, J.). Thus, ACCA’s reference to the CSA must incorporate “the federal drug schedules that are currently in

effect for sentencing purposes—i.e., those that were effective at the time of the federal offense.” Post, at 4. 

The problem for the dissent is that none of the cases it 
 

Cite as: 602 U. S. ____ (2024) 15 

Opinion of the Court 

cites supports this proposition. See Yellen v. Confederated 

Tribes of Chehalis Reservation, 594 U. S. 338, 344–348 

(2021); Astrue v. Capato, 566 U. S. 541, 547–549 (2012); 

Carachuri-Rosendo v. Holder, 560 U. S. 563, 566–570 

(2010); Holder v. Humanitarian Law Project, 561 U. S. 1, 

8–9 (2010). For good reason: as we have explained, crossreferences sometimes refer to the law as it currently exists, 

but they may also incorporate a referenced statute as it existed when the cross-reference was enacted. Supra, at 12. 

Indeed, many of the dissent’s cases stand for the unobjectionable proposition that courts must carefully consider the

text and context of each statute before adopting a one-sizefits-all approach to cross-references. See Herrmann v. Cencom Cable Assoc., Inc., 978 F. 2d 978, 983 (CA7 1992) (attempting to “do the least damage” to unravel “contradictory

enactments”); United States v. Head, 552 F. 3d 640, 645 

(CA7 2009) (rejecting a “categorical rule” for “statutory 

cross-references”); United States v. Ho, 984 F. 3d 191, 202 

(CA2 2020) (rejecting a reference-canon argument inconsistent with plain language).

Following the approach laid out by the dissent’s cases

thus brings us back to the question with which we started:

What is the best reading of ACCA’s cross-reference in light

of context, precedent, and statutory purpose? Supra, at 7. 

For the reasons we have explained, it is that a prior state 

drug conviction constitutes an ACCA predicate if the drugs

on the federal and state schedules matched when the state 

drug offense was committed. 

B 

We turn next to Brown’s interpretation, which would require the state and federal definitions to match when the

defendant is sentenced for a federal firearm offense. Brown 

first argues that his interpretation is grounded in ACCA’s 

text because it focuses on the “here-and-now import” of “historical facts.” Brief for Petitioner Brown 8. Specifically, 
 

 

16 BROWN v. UNITED STATES 

Opinion of the Court 

Brown notes that ACCA uses the “present participle of ‘involve,’” rather than “the past participle.” Reply Brief for

Petitioner Brown 2–3. And he suggests that the phrase “‘as 

defined in’” is likewise in the present tense. Id., at 3. 

Unfortunately for Brown, we have already rejected this

textual argument.6 The petitioner in McNeill likewise argued that the present-tense language in ACCA’s definition

of a “serious drug offense” indicated a present-day focus. 

563 U. S., at 820. Citing that language, he asked the Court 

to require federal courts to “loo[k] to the state law in effect

at the time of the federal sentencing,” ibid., but we declined 

to do so. Because “ACCA is concerned with convictions that 

have already occurred,” we held that it requires a historical 

inquiry into the state law at the time of that prior offense. 

Ibid. And the “[u]se of the present tense . . . d[id] not suggest otherwise.” Ibid. 

McNeill’s conclusion makes sense. Use of the present 

tense, as opposed to the past, was likely a stylistic rather

than a substantive choice. Around the time of ACCA’s enactment, legislative drafters were instructed, “[w]henever

possible,” to “use the present tense (rather than the past or 

future).” House Office of the Legislative Counsel, Style

Manual; Drafting Suggestions for the Trained Drafter 

§102(c), p. 2 (1989); see also D. Hirsch, Drafting Federal

Law §5.6, p. 45 (2d ed. 1989) (“Various commentators on

drafting have tried, over the years, to persuade drafters to

use the present tense . . . ”). So, at least in the instant context, we cannot place too much weight on the use of the present tense as opposed to the past.

Brown also claims that his reading is required by United 

States v. Schooner Peggy, 1 Cranch 103 (1801), which says 

that when the law changes while a case is in progress, the 

—————— 6The dissent makes a similar textual argument but does not grapple 

with our reasoning in McNeill v. United States, 563 U. S. 816 (2011). See 

post, at 6, and n. 2. 
 

Cite as: 602 U. S. ____ (2024) 17 

Opinion of the Court 

case must be decided under the new law.7 Id., at 110. But 

that principle does nothing to advance Brown’s position. 

Section 924(e)(2)(A)(ii) has not changed at any point in the 

litigation, from the time petitioners committed their federal

offenses until today. Then, as now, under §924 past state

drug possession offenses may qualify as ACCA predicates if 

the federal and state schedules matched when the state 

crimes occurred. 

C 

We conclude by addressing some additional arguments

advanced by both petitioners. First, they assert that our

interpretation should be rejected because it is underinclusive—specifically, because it would preclude ACCA enhancements for state offenses involving drugs added to the

federal lists only after the state crimes were committed. 

But none of the parties’ interpretations captures all cases 

involving career criminals. Indeed, Brown and Jackson are 

themselves asking to be exempted from ACCA’s reach even

though they both have a history of dealing drugs that remain prohibited by federal law.

Second, petitioners suggest that the Government’s interpretation is absurd because it “would exclude from ACCA’s 

reach all state drug convictions from before 1970” when the 

CSA was enacted. Brief for Petitioner Jackson 33; accord, 

Brief for Petitioner Brown 16. But whether or not this consequence is desirable, it is not absurd.

We can easily see a reason why Congress might have chosen not to count either federal or state drug convictions that 

—————— 7Brown also likens his interpretation to the “ordinary practice” of applying Guidelines sentencing enhancements as they exist at sentencing. 

Tr. of Oral Arg. 4. But there is reason to doubt that the Guidelines practice is relevant here. That is because Congress has expressly directed 

courts to apply the Guidelines “in effect on the date the defendant is sentenced.” 18 U. S. C. §3553(a)(4)(A)(ii). ACCA contains no similar instruction. 
 

18 BROWN v. UNITED STATES 

Opinion of the Court 

occurred before 1970. Before that time, “Congress ha[d] enacted more than 50 pieces of legislation relating to . . . dangerous drugs,” and this had “given rise to a confusing and 

often duplicative approach to . . . enforcement.” H. R. Rep. 

No. 91–1444, pt. 1, p. 6 (1970). The CSA was designed to

replace these scattered provisions “with a single comprehensive statute.” Cong. Research Serv., L. Sacco, Drug Enforcement in the United States: History, Policy, and Trends

5 (2014). It was reasonable for Congress to peg ACCA’s penalties to that new comprehensive regulatory scheme rather

than requiring courts to grapple with the welter of federal 

drug laws that previously existed.

Petitioners argue that the Government’s interpretation

would unduly burden courts and defendants by requiring 

them to undertake the laborious task of digging up old federal drug schedules and comparing those to the state laws

the defendants violated. But the difficulty of this task is 

overstated. Most drug convictions concern just a few drugs,

and the federal and state definitions of those drugs do not 

often change. In the cases now before us, the courts below 

had no apparent difficulty finding the needed information. 

Finally, both petitioners contend that the rule of lenity

counsels us to adopt their interpretations. It does not. Lenity applies only if a statute remains grievously ambiguous 

after we have consulted “‘everything from which aid can be

derived.’” Pugin v. Garland, 599 U. S. 600, 610 (2023) 

(quoting Ocasio v. United States, 578 U. S. 282, 295, n. 8 

(2016)). As we have explained, however, context, precedent,

and statutory design adequately show “ ‘what Congress intended.’” United States v. Castleman, 572 U. S. 157, 173 

(2014) (quoting Barber v. Thomas, 560 U. S. 474, 488 

(2010)).

In any event, neither Jackson’s nor Brown’s interpretation would be preferable for all defendants. Both interpretations could hurt defendants who committed or were sentenced for the felon-in-possession offense before the 
Cite as: 602 U. S. ____ (2024) 19 

Opinion of the Court 

addition of a drug to the federal schedules. As petitioners’ 

own briefs highlight, States sometimes criminalize drugs

before the Federal Government does so. See Brief for Petitioner Jackson 34–35; Brief for Petitioner Brown 17. For 

instance, Florida banned the stimulant known as bath salts 

10 months earlier than the Federal Government.8 And 

Utah criminalized the hallucinogen methoxetamine nearly 

a decade before the Federal Government followed suit. See 

2013 Utah Laws ch. 88; Schedules of Controlled Substances: Placement of Methoxetamine (MXE) in Schedule I,

87 Fed. Reg. 34166 (2022). State convictions for those drugs

that predate the federal amendments would not count as 

ACCA predicates under the Government’s interpretation

but may under petitioners’ interpretations. It would be odd 

to use the rule of lenity to help petitioners but harm others. 

* * * 

For these reasons, we hold that a state drug conviction

counts as an ACCA predicate if it involved a drug on the

federal schedules at the time of that offense. Accordingly,

we affirm the judgments of the Courts of Appeals. 

It is so ordered. 

—————— 8Florida Bans ‘Bath Salt’ Drugs After Violent Outbursts, Sun Sentinel 

(Jan. 27, 2011), https://www.sun-sentinel.com/2011/01/27/florida-bansbath-salt-drugs-after-violent-outbursts; Press Release, Dept. of Justice,

Drug Enforcement Admin., Chemicals Used in “Bath Salts” Now Under

Federal Control and Regulation (Oct. 21, 2011), https://www.dea.gov/

press-releases/2011/10/21/chemicals-used-bath-salts-now-under-federalcontrol-and-regulation. 
 

_________________ 

_________________ 

Cite as: 602 U. S. ____ (2024) 1 

JACKSON, J., dissenting 

SUPREME COURT OF THE UNITED STATES 

Nos. 22–6389 and 22–6640 

JUSTIN RASHAAD BROWN, PETITIONER 

22–6389 v. 

UNITED STATES 

ON WRIT OF CERTIORARI TO THE UNITED STATES COURT OF 

APPEALS FOR THE THIRD CIRCUIT 

EUGENE JACKSON, PETITIONER 

22–6640 v. 

UNITED STATES 

ON WRIT OF CERTIORARI TO THE UNITED STATES COURT OF 

APPEALS FOR THE ELEVENTH CIRCUIT 

[May 23, 2024] 

JUSTICE JACKSON, with whom JUSTICE KAGAN joins, and

with whom JUSTICE GORSUCH joins as to Parts I, II, and III, 

dissenting. 

The Court maintains that, “[s]tanding alone,” the text of

18 U. S. C. §924(e)(2)(A)(ii) “does not definitively answer” 

the question presented in these cases. Ante, at 7. Instead, 

says the majority, we must look beyond the text to precedent, statutory context, and purpose—which apparently 

converge to persuade the majority that §924(e)(2)(A)(ii) requires sentencing courts to apply the drug schedules in effect at the time of a defendant’s prior state drug conviction

when determining the applicability of the 15-year mandatory minimum in the Armed Career Criminal Act (ACCA).

But the relevant text does definitively answer the question

presented here. And it establishes that courts should apply 

the drug schedules in effect at the time of the federal firearms offense that triggers ACCA’s potential application. 

Nothing else—not precedent, context, or purpose—requires 
 

2 BROWN v. UNITED STATES 

JACKSON, J., dissenting 

a different result. Therefore, I respectfully dissent. 

I 

A 

As relevant here, ACCA imposes a 15-year mandatory 

minimum for defendants who commit a violation of §922(g) 

while having “three previous convictions . . . for . . . a serious drug offense.” 18 U. S. C. §924(e)(1). Notably, Congress

did not leave unanswered the question of which prior state

convictions qualify as “a serious drug offense” for ACCA 

purposes. Rather, ACCA expressly defines the term “serious drug offense” by direct reference to another federal law. 

To qualify as a “serious drug offense,” the prior state crime

must be one “involving manufacturing, distributing, or possessing with intent to manufacture or distribute, a controlled substance (as defined in section 102 of the Controlled Substances Act (21 U. S. C. [§]802)).”

§924(e)(2)(A)(ii). 

The dispute in these cases arises from the fact that the 

meaning of the term “controlled substance”—as defined by

federal law—can, and frequently does, change. Under the 

Controlled Substances Act, a controlled substance is “a drug

or other substance, or immediate precursor, included in 

schedule I, II, III, IV, or V.” 21 U. S. C. §802(6). Those five 

schedules, which are not contained in the statute itself, are 

lists of substances that are “updated and republished on an 

annual basis” by the Attorney General. §812(a). During 

this annual review, the Attorney General may add or remove drugs from the schedules based on various considerations, such as a drug’s “actual or relative potential for

abuse” or the “state of current scientific knowledge regarding the drug.” §811(c); see also, e.g., 21 CFR pt. 1308 (2023)

(setting forth the most recent drug schedules). Congress 

itself can also categorically remove substances from the 

schedules. See, e.g., 21 U. S. C. §802(16)(B) (excluding

hemp from the schedules). 
Cite as: 602 U. S. ____ (2024) 3 

JACKSON, J., dissenting 

By directing that the term “controlled substance” in 

ACCA be determined on the basis of the Controlled Substances Act’s definition—which itself references the federal 

drug schedules—Congress has opted to rely on a federal 

statute that contains its own cross-reference to a dynamic

list of prohibited substances. ACCA’s “serious drug offense”

definition thus incorporates those oft-changing drug schedules by reference. 

B 

The majority and I are in full agreement that, consequently, a sentencing court deciding whether to impose

ACCA’s 15-year mandatory minimum for a violation of 

§922(g) must consult those external drug schedules to determine whether the drug “‘involv[ed]’” in a prior state offense is a controlled substance under federal law. See ante, 

at 1–2. Yet, somehow, the majority concludes that the pertinent drug schedules for ACCA’s sentencing exercise are

those that were in effect when the prior state drug crime

occurred. In my view, a straightforward application of the 

aforementioned statutory text plainly establishes otherwise. 

First of all, ACCA expressly defines “serious drug offense,” §924(e)(2)(A), and “[w]hen a statute includes an explicit definition, we must follow that definition,” Burgess v. 

United States, 553 U. S. 124, 130 (2008) (internal quotation

marks omitted). Congress could have defined “serious drug 

offense” based solely on state law. It did not. Instead, Congress made clear that only state drug crimes that involve 

substances that qualify as “controlled substance[s]” under 

the Controlled Substances Act are sufficiently serious to 

warrant ACCA’s penalty. 

Second, the definition of “serious drug offense” that appears in ACCA cross-references the highly mutable federal 

drug schedules—a drafting device that does particular 
 

 

 

4 BROWN v. UNITED STATES 

JACKSON, J., dissenting 

work in the legislative context. Consistent with the operation of cross-references elsewhere, the cross-reference in 

ACCA’s “serious drug offense” definition necessarily directs

sentencing courts to consult the current federal drug schedules—i.e., those in effect at the time of the federal offense 

for which the defendant is being sentenced—rather than 

some earlier version of those lists. 

That is, quite simply, how cross-references work. When 

it comes time to interpret a statute, courts typically plug

the referenced provision, as they find it, into the statutory 

text. They do not consider, much less account for, any 

amendments that might have taken place over the course

of the referenced provision’s existence. Nor does it matter 

that the referenced statute is a separate pronouncement 

that has its own legislative history and course of development. 

Courts proceed in this straightforward plug-and-play

manner with respect to statutory cross-references because 

“the presumed temporal application of a statute” is when 

“the relevant activity that the [statute] regulates” occurs. 

Landgraf v. USI Film Products, 511 U. S. 244, 291 (1994) 

(Scalia, J., concurring in judgments). That presumption applies with full force to any provisions cross-referenced in a 

statute, because “incorporating one statute or system of

statutes into another . . . serves to bring into the latter all 

that is fairly covered by the reference.” Panama R. Co. v. 

Johnson, 264 U. S. 375, 392 (1924). And what is fairly covered is the referenced law as it exists when the statute’s 

application is required. See Landgraf, 511 U. S., at 291. 

Until today, that had been our consistent practice. See, 

e.g., Yellen v. Confederated Tribes of Chehalis Reservation, 

594 U. S. 338, 344–348 (2021) (applying the cross-referenced definition then in effect); Astrue v. Capato, 566 U. S. 

541, 547–549 (2012) (same); Carachuri-Rosendo v. Holder, 

560 U. S. 563, 566–570 (2010) (same); Holder v. Humanitarian Law Project, 561 U. S. 1, 8–9 (2010) (same). When a 
 

Cite as: 602 U. S. ____ (2024) 5 

JACKSON, J., dissenting 

statute contains a cross-reference to another provision, we 

have always simply applied the version of the other provision in effect at the time the cross-referenced provision was

needed, even if Congress amended that provision at some 

point in the past.

Of course, this way of interpreting statutes with crossreferences means that a change in the referenced provision

has the effect of changing the statute that contains the 

cross-reference. But that is a feature, not a bug, of statutory cross-references. In fact, Congress often uses the crossreference device in a statute “precisely because the [referenced provision] may be amended.” Herr-mann v. Cencom 

Cable Assoc., Inc., 978 F. 2d 978, 983 (CA7 1992) (Easterbrook, J.) (emphasis added). Far from being problematic, 

one useful feature of a statutory crossreference from the standpoint of the legislative drafter is 

that it “permits the effect of a change in one section to propagate to other, related, sections without rewriting all of 

those related sections.” Ibid. 

That basic understanding of how cross-references work

easily resolves these cases. ACCA mandates that, for the 

purpose of its “serious drug offense” definition, a “controlled

substance” must be determined in accordance with the Controlled Substances Act, 18 U. S. C. §924(e)(2)(A)(ii), and the 

Controlled Substances Act, in turn, looks to the substances 

on the drug schedules, 21 U. S. C. §802(6). Congress’s incorporation of the drug schedules by cross-reference in this

manner means that a sentencing court must plug in the 

drug schedules as it finds them based on when “the relevant 

activity that the [statute] regulates” occurs. Landgraf, 511 

U. S., at 291. For ACCA, as with other federal criminal 

statutes, that means the court must apply the drug schedules in effect when the defendant “commits the underlying 

conduct that makes the offender liable.” Dorsey v. United 
 

6 BROWN v. UNITED STATES 

JACKSON, J., dissenting 

States, 567 U. S. 260, 272 (2012).1 

To be sure, one consequence of this approach is that, as 

the drug schedules change, so does the meaning of “controlled substance” under ACCA. See Herrmann, 978 F. 2d, 

at 983. But, again, Congress seems to have intended that 

result, insofar as the statute it wrote pegs ACCA’s “serious 

drug offense” definition to lists of substances that the Attorney General is required to revisit on an annual basis. Indeed, Congress presumably chose to cross-reference those

drug lists (rather than copying them directly into ACCA)

precisely because of their dynamic nature. 

The fact that ACCA’s “serious drug offense” definition

uses the present tense, as the majority concedes, see ante, 

at 16, further bolsters the conclusion that Congress was 

consciously incorporating the annual updates that the federal drug schedules embody. As we have previously recognized, “the present tense generally does not include the 

past.” Carr v. United States, 560 U. S. 438, 448 (2010). If 

Congress had wanted to reference a past version of the drug 

schedules, it easily could have indicated as much in the text

of ACCA. But Congress used the present tense instead, directing sentencing courts to look to the meaning of “controlled substance” in effect when a defendant commits the 

federal crime requiring ACCA’s application, not at some 

previous point in time.2 

—————— 1Brown argues that, as a sentencing statute, ACCA incorporates the 

drug schedules that are in effect when a District Court gives legal effect

to its provisions—i.e., at the time of the federal sentencing. See ante, at 

6. While Congress determined that the Sentencing Guidelines should

follow that approach, see 18 U. S. C. §3553(a)(4)(A)(ii), we have recognized that the so-called federal saving statute, 1 U. S. C. §109, generally 

requires courts to apply the criminal statutes in effect at the time the

defendant committed the federal crime, see Dorsey, 567 U. S., at 272. 

Only Jackson’s approach is consistent with that precedent. See ante, at 

5. 2The majority attributes ACCA’s use of the present tense to a mere

“stylistic” choice by Congress, relying primarily on a contemporaneous 
Cite as: 602 U. S. ____ (2024) 7 

JACKSON, J., dissenting 

II 

The Government rejects the foregoing description of how 

statutory cross-references operate. Tr. of Oral Arg. 58 (expressing “disagree[ment] that the background rule is that 

we always look to the contemporaneous referenced law”). 

The Government insists that, instead of merely calling for 

insertion of the referenced law, the appearance of a cross-reference in a statute “raises a temporal question” that requires a court to determine “which version of [the cross-referenced provision] Congress intend[ed] to reference.” Id., 

at 56. As the Government sees it, every statutory crossreference can thus have “different temporal branches depending on context.” Id., at 58; see also ante, at 15 (appearing to adopt this temporally flexible approach to cross-references).

That cannot be right. We have never viewed statutory 

cross-references as a gateway to the multiverse. Cf. Clark 

v. Martinez, 543 U. S. 371, 382 (2005) (rejecting an approach that “would render every statute a chameleon”). No 

case that I am aware of has ever asked whether some past

version of the statute applies when the court is interpreting

a provision that contains a cross-reference—and neither the 

—————— 

legislative drafting manual as support for that conclusion. Ante, at 16. 

But the wholly speculative suggestion that ACCA’s drafters actually relied on the cited manual’s tense-related directives conveniently comes 

out of nowhere. Moreover, to the extent the majority now believes that

verb tense is irrelevant when a court undertakes to interpret the text of 

a statute, it has taken a strange and unwarranted departure from this 

Court’s ordinary interpretive practices. Before today, we have consistently used all aspects of a statute’s text to ascertain its meaning, including the verbs that Congress chooses. See, e.g., Barton v. Barr, 590 U. S. 

222, 236 (2020); Carr v. United States, 560 U. S. 438, 448 (2010); United 

States v. Wilson, 503 U. S. 329, 333 (1992); Gwaltney of Smithfield, Ltd. 

v. Chesapeake Bay Foundation, Inc., 484 U. S. 49, 57 (1987). An objection 

to this approach has surfaced only once before, in dissent. See Carr, 560 

U. S., at 462–464 (opinion of ALITO, J.) (relying on legislative drafting

manuals to suggest that the tense of the verbs in a statute was not relevant to the provision’s interpretation). 
 

 

 

8 BROWN v. UNITED STATES 

JACKSON, J., dissenting 

majority nor the Government cites any. In fact, our actual 

practices establish the contrary. Whenever we have addressed a statutory cross-reference, we have always taken 

the same tried-and-true approach that we employ with respect to statutory definitions: We plug in the referenced

provision as it exists at the moment the statute’s provisions 

become applicable. See Part I–B, supra. 

Any other approach risks chaos. Again, Congress often

uses cross-references in statutes “precisely because the [referenced provision] may be amended,” thereby allowing that 

amendment “to propagate to other, related, sections without rewriting all of those related sections.” Herrmann, 978 

F. 2d, at 983. The Government’s view would unsettle that 

longstanding drafting convention, injecting uncertainty

into what Congress must do to amend statutes using crossreferences. What is more, if every cross-reference raised a

question about which version of the referenced statute applies—past or present—interpretation of federal statutes

with cross-references would become entirely unworkable. 

Cross-references are legion in the U. S. Code, and crossreferenced statutes are regularly amended. Under the Government’s approach, every one of those amendments would 

become a jump ball, inviting competing interpretations 

about which version of the referenced statute applies.

The Government claims that this disordered way of applying cross-references stems from the so-called reference 

canon, which sometimes directs courts to apply a past version of a referenced statute. See Tr. of Oral Arg. 56, 58.3 

—————— 3The reference canon has two strains, general and specific. First, 

“[w]hen a statute refers to a general subject, the statute adopts the law 

on that subject as it exists whenever a question under the statute arises.” 

Jam v. International Finance Corp., 586 U. S. 199, 209 (2019). Second, 

when there is “a statute that refers to another statute by specific title or

section number,” that cross-reference “in effect cuts and pastes the referenced statute as it existed when the referring statute was enacted,

without any subsequent amendments.” Id., at 209–210; see also Hassett 

v. Welch, 303 U. S. 303, 314 (1938). It is not clear that this latter, specific 
 

Cite as: 602 U. S. ____ (2024) 9 

JACKSON, J., dissenting 

But even if the reference canon applies under these circumstances, it seems to cut against the Government’s interpretation. The Government asserts that, because ACCA references a specific section—“section 102 of the Controlled 

Substances Act,” 18 U. S. C. §924(e)(2)(A)(ii)—the reference

canon “would suggest that the ACCA incorporated the 

schedules as they existed in 1986, when the cross-reference

was enacted.” Brief for United States 42. But conspicuously missing from this discussion (as well as the majority’s

discussion of the reference canon, see ante, at 12–13) is the 

actual text of the cross-referenced provision at issue in

these cases, which comes nowhere near incorporation of a 

static, historical list of substances. 

Instead, as explained above, ACCA’s “serious drug offense” definition cross-references §102 of the Controlled 

Substances Act, see 18 U. S. C. §924(e)(2)(A)(ii), and under 

that provision, a “controlled substance” is “a drug or other 

substance, or immediate precursor, included in schedule I, 

II, III, IV, or V,” 21 U. S. C. §802(6) (emphasis added). This 

juxtaposition turns what appears to be a specific statutory 

reference into a more general one, since it is impossible to 

determine which substances fall under the statutory definition without knowing what the five schedules contain. And 

because those schedules are designed to change over time, 

it is hard to view ACCA’s reference to the controlled substances definition of the Controlled Substances Act as anything other than an instruction for courts to consult “an external body of potentially evolving law” and “adop[t] the law 

on that subject as it exists whenever a question under the 

—————— 

form of the canon even applies in the absence of uncertainty about what, 

exactly, is being cross-referenced, such as “a facial defect with the crossreference or target statute being interpreted.” United States v. Head, 

552 F. 3d 640, 647 (CA7 2009) (collecting cases); see also United States 

v. Ho, 984 F. 3d 191, 202 (CA2 2020) (forgoing “unnecessary resort to the

reference canon” and instead interpreting the statute consistent with its 

plain language). 
 

 

10 BROWN v. UNITED STATES 

JACKSON, J., dissenting 

statute arises.” Jam v. International Finance Corp., 586 

U. S. 199, 209–210 (2019).

The upshot is that proper application of the reference 

canon here leads to the same conclusion that I reached 

above. The cross-reference in ACCA incorporates drug

schedules that are updated annually and does so in the present tense, thereby requiring sentencing courts to merely

plug in the drug schedules in effect at the time of the defendant’s federal firearms offense—i.e., the relevant 

timeframe for the purpose of the court’s interpretation of

ACCA’s “serious drug offense” language. 

III 

In rejecting the typical, straightforward understanding of

ACCA’s cross-reference, the majority pivots away from the 

text of the statute entirely, and purportedly bases the 

Court’s conclusion on “precedent and statutory context.” 

Ante, at 7. Neither our precedents nor the context of this

statute actually compels a different conclusion than the text 

does, for the reasons explained below. 

A 

To start, the majority misreads our precedent. In McNeill 

v. United States, 563 U. S. 816 (2011), we considered how to 

determine whether a state drug crime involved “a maximum term of imprisonment of ten years or more” under 

state law. §924(e)(2)(A)(ii). McNeill instructed sentencing

courts making this determination to undertake a “backward-looking” inquiry by “consult[ing]” “the law under 

which the defendant was convicted”—that is, “the version 

of state law that the defendant was actually convicted of 

violating.” 563 U. S., at 820–821. 

The majority contends that this same “‘backwardlooking’” approach should apply to the federal drug schedules. Ante, at 8 (quoting McNeill, 563 U. S., at 820). But 

the federal drug schedules are not “the law under which the 
 

Cite as: 602 U. S. ____ (2024) 11 

JACKSON, J., dissenting 

defendant was convicted.” Id., at 820. And of course 

McNeill was “backward-looking”; any inquiry into a defendant’s statute of conviction is necessarily so. Here, both the 

Government and petitioners take as a given “the version of 

state law that the defendant was actually convicted of violating,” as McNeill instructs. Id., at 821. The question presented in these cases—on which the parties disagree—is

how to evaluate whether that prior state-law conviction

qualifies as a “serious drug offense” under federal law. 

In other words, McNeill asked what state crime the defendant committed, while today’s cases ask how ACCA assesses that conviction. The latter is an entirely distinct inquiry. And for all the reasons discussed above, the federal 

benchmark that Congress has selected is not “backwardlooking” in the least—it rationally incorporates the currently applicable drug schedules, not ones from the past. 

See Part I, supra. 

The majority’s opinion not only misconstrues McNeill, it 

also flatly contradicts other precedents from this Court outlining how to determine whether a prior state conviction

qualifies as an ACCA predicate. See, e.g., Mathis v. United 

States, 579 U. S. 500, 504 (2016); Taylor v. United States, 

495 U. S. 575, 599–602 (1990). As the majority only scantly 

mentions, to determine whether a state crime is a “serious 

drug offense,” courts are not supposed to rely on the actual 

or alleged facts related to the prior state drug crime. Rather, they ask “if the State’s definition of the drug in question ‘matche[s]’ the definition under federal law.” Ante, at 

2 (quoting Shular v. United States, 589 U. S. 154, 158 

(2020); alteration in original). We have referred to this 

matching process as the “‘categorical approach.’” Id., at 

157 (quoting Taylor, 495 U. S., at 600). 

Under that methodology, “[a] court must look only to the

state offense’s elements, not the facts of the case or labels 

pinned to the state conviction.” Shular, 589 U. S., at 160. 

Thus, we do not ask how the State classified or categorized 
 

12 BROWN v. UNITED STATES 

JACKSON, J., dissenting 

the prior offense. Nor does it matter what type of drug a 

defendant actually manufactured, possessed, or sold. Such 

facts are “extraneous to the crime’s legal requirements,”

and “ACCA, as we have always understood it, cares not a

whit about them.” Mathis, 579 U. S., at 504. Properly applied, the categorical approach mandates that a court’s sole

focus must be on identifying the state crime’s statutory elements and determining whether they categorically match

the ACCA predicate. 

By appearing to fixate on the facts of petitioners’ prior

state drug offenses, the majority’s opinion thus diverges

from our precedents. For example, the majority puzzlingly

suggests that our standard methodology for assessing state 

crimes in relation to federal law provides a loophole for 

these petitioners, because “Brown and Jackson were themselves convicted of crimes involving substances that are still

on the federal schedules, marijuana and cocaine, not hemp

or [123I]ioflupane.” Ante, at 10. But, again, the entire point

of the categorical approach is that courts may consider only

the state crime’s elements, not the substances actually involved in that crime, when undertaking to determine 

whether the state crime matches the federal standard. 

This matters because ensuring adherence to the categorical approach, which the majority fails to do here, serves 

important objectives. We employ the categorical approach

not only because Congress commanded it, see Taylor, 495 

U. S., at 589, but also because it “avoids unfairness to defendants,” Mathis, 579 U. S., at 512, who may not have

sought to have the state records accurately reflected the details of the crime they committed. 

Suppose, for example, that Brown—whose conviction was 

reportedly for marijuana—was, in fact, prosecuted by the

State for conduct involving hemp, as some defendants were. 

See, e.g., Commonwealth v. Harrelson, 14 S. W. 3d 541, 544 

(Ky. 2000); see also New Hampshire Hemp Council, Inc. v. 

Marshall, 203 F. 3d 1, 5 (CA1 2000) (noting that “the threat 
 

Cite as: 602 U. S. ____ (2024) 13 

JACKSON, J., dissenting 

of federal prosecution [was] realistic” when hemp was still 

on the federal schedules). The distinction between a conviction for a drug crime involving marijuana versus one involving hemp could be a significant one for purposes of a 

future firearms prosecution that might trigger ACCA. But 

a defendant in Brown’s position would likely have “no incentive to contest” that his conduct involved hemp, not another form of marijuana, during the state prosecution because that fact did “not matter under the law” at that time. 

Mathis, 579 U. S., at 512. Indeed, he might well have been

“precluded from doing so by the [state] court.” Ibid. It is 

highly unlikely that such a defendant could even contemplate that his state conviction would be relevant to a future

ACCA conviction, because most state crimes have “no significance under federal law for years to come.” Johnson v. 

United States, 544 U. S. 295, 305 (2005). 

Unfairness arises without the categorical approach, because such a defendant’s punishment would be significantly 

increased under ACCA for a prior state crime involving

hemp simply due to his failure to anticipate, at the time of

his state convictions, a future change in the federal drug 

schedules. The categorical approach responds to that unfairness by relying exclusively on the elements of the state

crime, rather than the underlying facts of the crime. 

So, as long as the drug substances expressly prohibited 

by state law differ from those that the federal law proscribes, then that state law is not a categorical match to

ACCA’s “serious drug offense” definition, and a conviction

under that statute cannot be used as an ACCA predicate.

Here, however, the majority suggests that the categorical 

mismatch is irrelevant because, regardless, petitioners’ 

state crimes actually involved types of drugs that have remained on the federal schedules during all potentially pertinent time periods. Ante, at 10. That reasoning not only

fails to follow our well-established methodology, it also perpetuates the same unfairness that the categorical approach 
 

14 BROWN v. UNITED STATES 

JACKSON, J., dissenting 

is designed to mitigate. 

B 

The majority fares no better with statutory context. The 

majority’s opinion points to ACCA’s other definition of “serious drug offense,” 18 U. S. C. §924(e)(2)(A)(i), which classifies certain federal crimes as “serious drug offenses.” That 

provision defines a “serious drug offense” as “an offense under the Controlled Substances Act (21 U. S. C. [§]801 

et seq.), the Controlled Substances Import and Export Act

(21 U. S. C. [§]951 et seq.), or chapter 705 of title 46 for 

which a maximum term of imprisonment of ten years or 

more is prescribed by law.” §924(e)(2)(A)(i). As the majority notes, this definition turns solely on “whether a defendant was convicted and sentenced for such an offense, and a 

later change in a federal drug schedule cannot change that

fact.” Ante, at 8 (footnote omitted). In the majority’s view,

we should avoid “treat[ing] . . . federal and state offenses 

differently,” so the applicability of ACCA’s penalty to prior 

state crimes, too, must be based simply on whether the federal drug schedules matched state law at the time of the 

defendant’s prior state conviction. Ibid. 

Whatever the merits of treating federal and state offenses

the same way might be, Congress did not draft ACCA to

achieve that result. When this Court previously addressed 

these same two ACCA provisions in response to a similar 

argument, it recognized that “the divergent text of the two

provisions of the serious-drug-offense definition . . . makes 

any divergence in their application unremarkable.” Shular, 

589 U. S., at 164 (internal quotation marks omitted). Congress certainly could have used the same classification metric for federal and state priors—say, by classifying federal 

crimes as “serious drug offenses” based on the particular

controlled substances involved, as it did with state crimes— 

but did not do so. And we generally “‘presume differences 

in language . . . convey differences in meaning,’” especially 
Cite as: 602 U. S. ____ (2024) 15 

JACKSON, J., dissenting 

“when the same Congress passed both statutes to handle 

much the same task.” Wisconsin Central Ltd. v. United 

States, 585 U. S. 274, 279 (2018) (quoting Henson v. Santander Consumer USA Inc., 582 U. S. 79, 86 (2017)). Congress’s choice to phrase the two “serious drug offense” definitions in ACCA differently “requires respect, not 

disregard.” Wisconsin Central, 585 U. S., at 279. 

At any rate, unlike the first subsection of ACCA’s “serious

drug offense” definition, the second subsection involves

classifying state crimes based on federal law—a circumstance that, as I previously explained, requires the categorical approach. See supra, at 13–14. This means that some 

federal-state discrepancy as to the kinds of crimes that are

deemed “serious drug offenses” is not at all surprising or 

unusual; it is par for the course. See Shular, 589 U. S., at 

164. 

To see why, consider one example. The Controlled Substances Act provides that “it shall be unlawful for any person knowingly or intentionally . . . to manufacture, distribute, or dispense, or possess with intent to manufacture, 

distribute, or dispense, a controlled substance.” 21 U. S. C. 

§841(a)(1). We have previously recognized that “the statute’s word ‘knowingly’ . . . appl[ies] to all the subsequently 

listed elements of the crime” in this provision, meaning that 

the Government must prove that a defendant knew he was 

dealing with a controlled substance. Flores-Figueroa v. 

United States, 556 U. S. 646, 650 (2009). State law, by contrast, does not always include such a knowledge requirement. See United States v. Smith, 983 F. 3d 1213, 1223 

(CA11 2020). We have nonetheless recognized that ACCA

applies differently to state and federal drug crimes on this 

basis. See Shular, 589 U. S., at 164. 

Thus, the ultimate question is not whether ACCA requires consistency between the classification of federal and

state crimes, as the majority suggests. Instead, given some 

inevitable inconsistency between state and federal law, our 
 

 

16 BROWN v. UNITED STATES 

JACKSON, J., dissenting 

inquiry is “which form of consistency Congress intended.” 

Id., at 165. Here, Congress’s use of an express cross-reference to the Controlled Substance Act’s mutating drug

schedules in the state-crime definition—coupled with its

omission of such a cross-reference in the federal-crime definition—indicates that inconsistency based on drug type 

was not only anticipated but intended. 

In short, the presence of a differently worded 

§924(e)(2)(A)(i) does not overcome the plain meaning of 

§924(e)(2)(A)(ii). 

IV 

Finally, the majority contends that its reading “best fulfills ACCA’s statutory objectives.” Ante, at 9. But that assertion fails to appreciate ACCA’s actual goals. Congress

has plainly designated serious drug offenses in a defendant’s criminal history as triggers for ACCA’s 15-year mandatory minimum for a reason—because the seriousness of 

the defendant’s prior drug-related history is indicative of 

that defendant’s future dangerousness, given the present 

firearms offense. The majority’s analysis falters because it 

does not, and frankly cannot, explain how future dangerousness is best assessed by reference to outdated drug 

schedules. 

Congress indisputably enacted ACCA to incapacitate

what it viewed to be a class of especially dangerous defendants—“the eponymous ‘armed career criminal.’” Wooden v. 

United States, 595 U. S. 360, 375 (2022). The 15-year mandatory minimum that ACCA imposes is among the harshest 

mandatory penalties in the Federal Criminal Code, and 

“the length of the mandatory minimum was set at 15 years” 

specifically “to incapacitate the armed career criminal for 

the rest of the normal time span of his career[,] which usually starts at about age 15 and continues to about age 30.” 

S. Rep. No. 97–585, p. 7 (1982). This means that ACCA is 

not a simple recidivist statute that merely tallies up past 
Cite as: 602 U. S. ____ (2024) 17 

JACKSON, J., dissenting 

offenses, as the majority suggests, see ante, at 10–11, 

thereby imposing a drastically increased penalty for illegal 

firearms possession based on a “once a criminal, always a

criminal” perspective. Rather, Congress designed ACCA to 

help courts identify a certain category of defendants—those 

who, having a particular kind of criminal history and now 

unlawfully possessing a gun, pose such a distinct risk of future dangerousness that a lengthy term of incapacitation is 

warranted.4 

“In order to determine which offenders fall into this category,” ACCA directs a sentencing court to conduct a review 

of a defendant’s “past crimes” under state law, looking for 

violent felonies or serious drug offenses, “because . . . criminal history is relevant . . . to the kind or degree of danger 

the offender would pose were he to possess a gun.” Begay 

v. United States, 553 U. S. 137, 146 (2008). But, importantly, ACCA does not deem every state crime a predicate for the 15-year mandatory minimum. Instead, the 

statute specifies certain categories of crimes that trigger

application of the prescribed penalty, due to the “prior

crime’s relevance to the possibility of future danger with a 

gun.” Ibid. 

ACCA’s focus on incapacitating certain defendants based

on their potential future dangerousness makes it entirely

sensible that the statute directs courts to identify “serious 

drug offense[s]” (as well as “violent felon[ies]”) in a defendant’s background. 18 U. S. C. §924(e)(1). What does not 

make sense is the majority’s suggestion that ACCA requires 

the extended incapacitation of defendants based on past 

criminal conduct that federal law does not deem serious to-

—————— 4 “Of course, to say that Congress had reasons” to enact ACCA’s sentencing scheme “is not to endorse those policy choices.” Consumer Financial Protection Bureau v. Community Financial Services Assn. of 

America, Ltd., 601 U. S. ___, ___ (2024) (JACKSON, J., concurring) (slip 

op., at 3). 
 

18 BROWN v. UNITED STATES 

JACKSON, J., dissenting 

day. In other words, if the point of ACCA is the incapacitation of certain defendants—those whose histories of serious 

criminality indicate a propensity to commit future dangerous crimes in light of their unlawful possession of a 

weapon—how does a record that contains past crimes involving drugs that are no longer controlled substances help 

to identify especially dangerous defendants? It does not.

 In reality, that goal is achieved only by determining 

whether a defendant’s past crimes are considered serious

by today’s standards. The federal drug schedules are specifically updated to account for current views of dangerousness. See Part I–A, supra. And a drug’s removal from those 

schedules reflects a determination that the drug is no

longer deemed dangerous based on criteria such as “[i]ts actual or relative potential for abuse” and “[t]he state of current scientific knowledge regarding the drug.” 21 U. S. C. 

§811(c). Accordingly, ACCA is best interpreted as referencing the drug schedules that are effective as of the date of 

the commission of the gun crime that triggers ACCA’s applicability, rather than those that would have signaled seriousness at some prior time. “Indeed, it would be illogical 

to conclude that federal sentencing law attaches ‘culpability 

and dangerousness’ to an act that . . . Congress has concluded is not culpable and dangerous.” United States v. 

Bautista, 989 F. 3d 698, 703 (CA9 2021) (Fletcher, J.). 

Meanwhile, the majority’s view misses the mark that 

Congress set for ACCA’s sentencing scheme in another respect as well: It leaves out many defendants who do warrant incapacitation for dangerousness—those who have

prior convictions for trafficking drugs that were scheduled

as controlled substances by the time their §922(g) offenses 

were committed but were not on the federal drug schedules

when their prior state convictions occurred. The majority

concedes that its interpretation would exclude from ACCA’s

“serious drug offense” definition state drug crimes that occur when “States . . . criminalize drugs before the Federal 
Cite as: 602 U. S. ____ (2024) 19 

JACKSON, J., dissenting 

Government does so.” Ante, at 19. This happens not infrequently, such as when a State criminalizes new, cuttingedge drugs. See, e.g., ibid. (discussing the criminalization

of bath salts and methoxetamine by States before the Federal Government); see also Brief for Petitioner Jackson 34–

35 (citing other examples); Brief for Petitioner Brown 17

(same).

Under the majority’s approach, ACCA’s intended assessment of future dangerousness via the consideration of past

state drug crimes would not apply to defendants if their 

prior state convictions took place before the drugs they trafficked were federally scheduled. But under the statutory

scheme Congress actually adopted, there is no reason a defendant’s early engagement with dangerous new drug substances criminalized by state law should not qualify as

ACCA predicates, especially since the federal drug schedules are frequently updated to account for precisely this sort 

of newfound danger, consistent with ACCA’s broader approach.

Ultimately, then, for all its talk of statutory goals, the

majority’s opinion elides the true purpose of ACCA’s mandatory minimum scheme in multiple ways. It also downplays the means Congress adopted to advance its incapacitation objectives, by essentially ignoring the link the 

statute draws between potential future dangerousness, as 

partially evidenced by the seriousness of a defendant’s past 

drug activity, and the need for lengthy incapacitation, 

which the statute provides. Breezing past these key nuances, the majority simply announces its own apparent 

view that “[a] prior drug conviction for an offense punishable by 10 years’ imprisonment augurs a risk of future dangerousness even if the drug is no longer considered dangerous.” Ante, at 11.5 

—————— 5The majority’s opinion offers no concrete evidence for this empirical 
 

 

20 BROWN v. UNITED STATES 

JACKSON, J., dissenting 

* * * 

At bottom, the majority’s reasoning appears to reduce to 

a disagreement with Congress’s legislative judgment, embodied in the text of the Controlled Substances Act, that a 

change in the drug schedules is a change in the perceived 

dangerousness of a drug that should have a material impact 

on the determination whether incapacitation is warranted.

See 21 U. S. C. §811(a). The Court’s ruling thus displaces 

Congress’s decision to base ACCA’s 15-year mandatory penalty on the evolving dangerousness determinations that the

Controlled Substances Act incorporates rather than on

static impressions about a defendant’s recidivist tendencies 

based solely on the fact that they have previously committed crimes. 

The majority’s contrary holding seems to reflect its own

policy view that “Brown’s and Jackson’s multiple convictions” pose a significant risk of future dangerousness “despite the technical changes to the federal drug schedules.” 

Ante, at 11. But the choice of how to assess and address 

dangerousness belongs first and foremost to Congress. And 

for the reasons I have explained, Congress designed ACCA 

to take a different approach—to measure future dangerousness by today’s drug schedules, not outdated ones from the 

past. See Part I, supra. One might harbor doubts that the 

—————— 

assertion. And its strained analogy to bootleggers at the end of Prohibition, who supposedly “shifted to other illegal enterprises,” ante, at 11, 

paints a woefully incomplete historical picture. Contrary to the majority’s contentions, the end of Prohibition allowed many of those previously

involved in the illegal alcohol trade to transition into successful, legitimate careers. See, e.g., D. Okrent, Last Call: The Rise and Fall of Prohibition 359–360 (2010) (discussing Samuel Bronfman, a former bootlegger

who turned his company Seagram’s into one of the largest

liquor-distribution corporations in the world). Regardless, there is

simply no evidence in ACCA’s legislative history or otherwise that Congress drew the same historical lessons from Prohibition that the majority

does, or that ACCA was motivated in any respect by our Nation’s experiences during Prohibition. 
Cite as: 602 U. S. ____ (2024) 21 

JACKSON, J., dissenting 

sentencing policy that Congress enacted is sensible, just, or 

effective. But it is the one that Congress wrote, and we remain dutybound to apply the law as written. In my view,

the majority has failed to do so here.