First Circuit Rule: Career-Offender “Controlled Substance” Is Defined by Federal Schedules at Federal Sentencing (Not State Law and Not the Time of the Prior Conviction)

I. Introduction

In United States v. Fulcar (1st Cir. July 6, 2026), Rey David Fulcar appealed from three federal convictions entered on unconditional guilty pleas in the District of Massachusetts: (i) felon-in-possession under 18 U.S.C. § 922(g)(1), and (ii) two drug counts under 21 U.S.C. § 841(a)(1). He also appealed the Guidelines calculations used at sentencing.

The appeal raised four clusters of issues: (1) whether Fulcar’s guilty pleas to counts dependent on home-search evidence were unknowing/involuntary because the court did not warn that an unconditional plea would forfeit appellate review of the suppression ruling; (2) whether § 922(g)(1) violated the Second Amendment after New York State Rifle & Pistol Association, Inc. v. Bruen; (3) whether the district court erred by applying the “career offender” enhancement under U.S.S.G. § 4B1.1; and (4) whether two firearm-related enhancements under U.S.S.G. § 2K2.1 were applied (or effectively found) erroneously.

The First Circuit affirmed all convictions and the 96-month sentence, but it did so while announcing a significant interpretive clarification: for the career-offender guideline, “controlled substance” is determined by federal law (not state law), and by the federal schedules as they exist at the time of federal sentencing (not the time of the prior conviction). On the facts here, that meant the district court erred in applying career-offender status—yet the error was harmless because the district judge made an unequivocal alternative-variance statement under 18 U.S.C. § 3553(a).

II. Summary of the Opinion

  • Rule 11 / plea validity: No plain error where the district court did not advise that an unconditional guilty plea bars appeal of a suppression ruling; the First Circuit refused to add a “new core concern” to Rule 11 beyond existing precedent.
  • Second Amendment challenge: Deemed waived due to improper incorporation by reference and undeveloped argument; Fulcar did not engage the district court’s reliance on controlling First Circuit precedent, United States v. Torres-Rosario.
  • Career offender guideline: The district court erred in treating Fulcar’s 2008 Massachusetts conviction for possession with intent to distribute “cocaine” as a qualifying “controlled substance offense,” because Massachusetts “cocaine” included ioflupane while the federal schedules excluded ioflupane at the time of federal sentencing.
  • Harmlessness: The error was harmless because the district court stated it would impose the same 96-month sentence regardless of the disputed Guidelines issues, after considering § 3553(a).
  • Other enhancements (U.S.S.G. § 2K2.1): Even if debatable, any error would also be harmless under the same alternative-sentence reasoning.

III. Analysis

A. Precedents Cited

1. Search warrants, suppression, and what survived the guilty pleas

The district court denied suppression both on warrant validity and good faith, relying on United States v. Leon, 468 U.S. 897 (1984). On appeal, however, Fulcar’s suppression arguments were reachable only if his pleas were invalid; otherwise, his unconditional pleas foreclosed that litigation. The First Circuit’s factual framing followed its usual record-based approach cited in United States v. McKinney and United States v. Santa-Soler.

2. Rule 11, due process, and plain-error review

Because Fulcar did not raise the Rule 11 theory below, review proceeded under the plain-error framework articulated in United States v. Kitts, with the procedural plain-error rule drawn from United States v. Williams and United States v. Vonn. The panel rejected the contention that due process requires warnings beyond Rule 11’s requirements, leaning on the First Circuit’s linkage between Rule 11 and due process in United States v. Cotal-Crespo. The “no clear or obvious error” point also invoked United States v. Romero.

Crucially, United States v. Williams controlled the specific claim: the court reiterated that it had already “declined … to add a new core concern” requiring a judge to ensure the defendant understands that pleading guilty waives the right to challenge seizures of evidence. That foreclosed Fulcar’s “you must warn me that a conditional plea is required” theory on plain-error review.

3. Waiver and incorporation by reference on the Second Amendment issue

Fulcar invoked New York State Rifle & Pistol Association, Inc. v. Bruen and District of Columbia v. Heller but largely incorporated district-court arguments by reference. The First Circuit applied its strict anti-incorporation line from United States v. Orrego-Martinez, Gilday v. Callahan, and Sleeper Farms v. Agway, Inc., and its undeveloped-argument waiver rule from United States v. Zannino. It also noted Fulcar’s failure to address the district court’s reliance on United States v. Torres-Rosario, and cited Sparkle Hill, Inc. v. Interstate Mat Corp. for the requirement to confront dispositive reasoning.

4. Sentencing review standards, harmlessness, and choosing to decide a legal issue anyway

Guidelines interpretation is reviewed de novo and factfinding for clear error under United States v. Carvajal (quoting United States v. Ruiz-Huertas). Even when an error exists, the sentence may be affirmed if the error did not affect the outcome, per United States v. Marsh.

The court emphasized the alternative-sentence doctrine: when the district court makes clear it would impose the same sentence regardless of the Guidelines, error is harmless—citing United States v. Ouellette.

Notably, the panel still decided the career-offender issue “head-on” despite harmlessness because: the government did not press harmlessness; the issue was fully briefed; it was pure law; and it recurred in sentencing and plea negotiations. The court cited United States v. Soto-Sanchez to justify deciding an otherwise harmless legal issue to clarify uncertain law.

5. The new interpretive holdings: timing and the source of “controlled substance”

The court addressed two interlocking interpretive questions for U.S.S.G. § 4B1.1/§ 4B1.2:

  1. Timing: whether “controlled substance” is assessed at the time of federal sentencing or the time of the prior conviction.
  2. Source of law: whether “controlled substance” is defined by federal law only or can be defined by state law for state predicates.

On timing, the government argued that United States v. Abdulaziz should be revisited after Brown v. United States. The panel assumed (without deciding) that Brown v. United States undermined United States v. Abdulaziz’s rationale, and then reconsidered the issue afresh. It held that the career-offender guideline is oriented to the time of federal sentencing, relying heavily on the “reference canon” as described in Brown v. United States (quoting Jam v. Int'l Fin. Corp.), and distinguishing ACCA’s specific statutory cross-reference logic from the Guidelines’ use of a general term. The panel found the Fifth Circuit’s post-Brown treatment persuasive, citing United States v. Minor, and discussed (but did not adopt) contrary circuit decisions including United States v. Nelson, United States v. Drake, and United States v. Piett.

On the source-of-law question, the court identified a circuit split and “join[ed]” the Second/Fifth/Ninth approach (federal-law-only), citing United States v. Townsend, United States v. Gomez-Alvarez, and United States v. Bautista, and rejecting the Third/Fourth/Sixth/Seventh/Eighth/Tenth/Eleventh approach reflected in United States v. Lewis, United States v. Ward, United States v. Jones (6th Cir.), United States v. Ruth, United States v. Henderson, United States v. Jones (10th Cir.), and United States v. Dubois.

The panel also leveraged its own earlier discussion in United States v. Crocco (which had been plain-error constrained) as supportive dicta, and bolstered the federal-law-only approach via the Supreme Court’s uniformity presumption in Jerome v. United States, as well as interpretive support from Esquivel-Quintana v. Sessions. It cited additional authorities that undergird its interpretive posture and potential lenity backstop: United States v. Pelzer, Seaboard Air Line Ry. v. Horton, Shaw v. United States (quoting Muscarello v. United States), United States v. Ahlers, and United States v. Luna-Diaz.

B. Legal Reasoning

1. The categorical approach as the methodological foundation

Both parties agreed the categorical approach applies. The court reiterated that under the categorical approach it must presume the prior conviction “rested upon nothing more than the least of the acts criminalized,” citing Thompson v. United States, and must look only to elements, not conduct, citing United States v. García-Cartagena.

That mattered because Massachusetts “cocaine” (Class B) included ioflupane, while the federal schedules excluded ioflupane at the time of Fulcar’s federal sentencing. Under the categorical approach, Fulcar’s prior “cocaine” conviction had to be treated as potentially covering ioflupane, making it overbroad if the guideline’s “controlled substance” is defined by federal schedules.

2. Timing: the First Circuit selects a federal-sentencing reference point

After engaging the government’s argument that Brown v. United States undermined United States v. Abdulaziz, the court held that for the Guidelines the operative definition is the one “at the time of … application … at … federal sentencing.” The key analytic move was to distinguish ACCA’s specific cross-reference from the Guidelines’ general terminology, applying Brown v. United States’s explanation of the reference canon (quoting Jam v. Int'l Fin. Corp.) to show why a general reference tends to incorporate the law “whenever a question … arises.”

The panel also noted that Brown v. United States itself acknowledged Guidelines practice differs because Congress directs courts to apply the Guidelines in effect at sentencing (citing 18 U.S.C. § 3553(a)(4)(A)(ii) via Brown v. United States n.7). It further rejected “absurdity” objections echoed in the dissent in United States v. Minor, reasoning that differential treatment around legal change is routine in Guidelines administration.

3. Source of law: “controlled substance” is federal-only even for state predicates

The court held that the guideline term “controlled substance” is defined exclusively by federal law. It reasoned that, absent a “plain indication” to the contrary, federal law should not be made dependent on state definitions—invoking Jerome v. United States’s nationwide-uniformity presumption (and its reliance on United States v. Pelzer and Seaboard Air Line Ry. v. Horton). The court treated “controlled substance” much like “felony” in Jerome v. United States: a general term whose incorporation of state variability would undermine uniform federal administration.

The government argued the Commission’s history and drafting choices showed intent to incorporate state controlled-substance lists. The court rejected that inference: (i) guideline history did not resolve the ambiguity about what “controlled substance” means; (ii) the guideline’s express inclusion of “offense under … state law” answers only what counts as an “offense,” not what counts as a “controlled substance”; and (iii) the lack of a CSA cross-reference did not affirmatively signal state-law dependence (and could have caused other interpretive complications under the reference canon).

As a final backstop, the panel stated that even if ambiguity remained “grievous,” lenity would favor the defendant, citing Shaw v. United States (quoting Muscarello v. United States), United States v. Ahlers, and United States v. Luna-Diaz.

4. Application to ioflupane and the Massachusetts “cocaine” predicate

The factual/legal mismatch was straightforward once the interpretive rules were set:

  • Massachusetts Class B “cocaine” included ioflupane at all relevant times.
  • Federal schedules excluded ioflupane beginning in 2015 and still excluded it at Fulcar’s federal sentencing (citing 21 C.F.R. § 1308.12 and the Federal Register notice identified in the opinion).
  • Therefore the Massachusetts statute was categorically overbroad relative to the federal “controlled substance” definition at sentencing.
  • Thus the 2008 conviction did not qualify as a “controlled substance offense” under U.S.S.G. § 4B1.2(b), and the career offender enhancement under § 4B1.1 was erroneously applied.

5. Harmless error carries the day

Despite finding legal error, the First Circuit affirmed because the district judge expressly stated that even if she “accepted” Fulcar’s guideline arguments she would “still [have] reached the same sentence” after considering § 3553(a). Under United States v. Marsh and United States v. Ouellette, that alternative-sentence statement rendered the guideline error harmless. The same harmlessness logic disposed of the § 2K2.1 enhancement disputes.

C. Impact

1. A major First Circuit clarification with practical leverage in sentencings and pleas

The opinion’s most consequential holding is its two-part clarification for the career-offender guideline (and, by its reasoning, other guideline provisions that use the same “controlled substance offense” definition):

  • Federal-law-only definition: A state predicate counts only if it criminalizes substances that are controlled under federal law (CSA schedules), not merely under the state’s controlled-substance list.
  • Time-of-federal-sentencing focus: Whether the substance is federally controlled is assessed at the time of federal sentencing (i.e., guideline application), not at the time of the prior conviction.

That combination is particularly significant because it can exclude otherwise common state predicates in jurisdictions whose controlled-substance schedules are broader than federal schedules or are not promptly updated when federal scheduling changes. The opinion also signals that such interpretive issues are sufficiently “recurring” to warrant resolution even when harmlessness would allow avoidance—encouraging future litigants to raise and preserve these issues.

2. Interaction with U.S.S.G. § 2K2.1 and other cross-references

The panel noted that § 2K2.1(a)(2) incorporates the career-offender definition of “controlled substance offense” (U.S.S.G. § 2K2.1 cmt. n.1). As a result, the federal-only/time-of-sentencing rule is poised to affect firearms cases where § 2K2.1(a)(2) depends on predicate “controlled substance offense” convictions—though in Fulcar’s case it did not matter because the error was harmless.

3. Appellate practice: strict enforcement of waiver and no incorporation by reference

The Second Amendment portion of the opinion reinforces that litigants must develop appellate arguments in the brief and must address controlling circuit precedent. Post-Bruen constitutional challenges will not be entertained if presented as cursory assertions with incorporation by reference.

4. Sentencing litigation: the power (and risk) of alternative-sentence statements

The case also underscores that a carefully articulated alternative sentence under § 3553(a) can insulate a sentence from remand even when the Guidelines were misapplied. For defense counsel, it increases the importance of contesting both (i) the Guidelines calculation and (ii) the substantive reasonableness and factual basis of any asserted alternative variance.

IV. Complex Concepts Simplified

  • Categorical approach: A court compares the legal elements of the prior offense to the guideline definition and assumes the conviction could have involved the least serious conduct covered by the statute—without looking at what the defendant actually did.
  • Plain error review: If an issue wasn’t raised in the district court, the appellant must show a clear/obvious error that affected substantial rights and seriously harmed the fairness or integrity of proceedings.
  • Waiver/forfeiture for undeveloped arguments: Appellate courts can refuse to consider arguments that are merely asserted, incorporated by reference, or not meaningfully developed with analysis and authority.
  • Reference canon: A rule of interpretation: a specific statutory cross-reference tends to incorporate the referenced law as fixed at a particular time, while a general reference tends to track the law as it exists when applied.
  • Jerome presumption: Absent a clear indication otherwise, federal law is usually interpreted not to depend on varying state-law definitions, promoting nationwide uniformity.
  • Harmless error in sentencing: Even if the court made a Guidelines mistake, there is no remand if the judge clearly would have imposed the same sentence after considering the statutory sentencing factors.
  • Grouping (U.S.S.G. §§ 3D1.2, 3D1.3): Multiple counts may be “grouped” so that the offense level is driven by the most serious grouped count rather than separately stacking calculations.

V. Conclusion

United States v. Fulcar affirms the convictions and sentence, but it materially reshapes First Circuit Guidelines doctrine on “controlled substance offense” predicates. The court held that (1) “controlled substance” under the career-offender guideline is defined by federal law, not state schedules, and (2) the relevant federal schedules are those in effect at the time of federal sentencing. Applied here, that made Fulcar’s Massachusetts “cocaine” predicate non-qualifying because it encompassed ioflupane, which federal law had excluded—rendering the career-offender enhancement erroneous. The sentence nonetheless stood because the district court’s unequivocal alternative § 3553(a) rationale made the error harmless.