Time-of-Offense Controls ACCA “Serious Drug Offense” Status: Sixth Circuit Applies Brown v. United States in United States v. Wilkes

Introduction

In United States v. Idris Quintell Wilkes (No. 22-1436, 6th Cir. Apr. 1, 2025), the Sixth Circuit issued a published successive opinion affirming a 15-year mandatory minimum sentence under the Armed Career Criminal Act (ACCA), 18 U.S.C. § 924(e)(1). Wilkes, who pleaded guilty to being a felon in possession of a firearm, challenged the use of four prior Michigan cocaine convictions as ACCA “serious drug offense” predicates. Two issues were raised across the appeal:

Whether Michigan’s coverage of all cocaine stereoisomers is broader than federal law (resolved against Wilkes in the court’s 2023 decision).
Whether Michigan’s inclusion of [123I]ioflupane in its cocaine definition—after the federal government removed it from the federal schedules in 2015—creates a categorical mismatch, rendering the convictions non-predicate offenses.

The panel (Judges Stranch, Murphy, and Davis) held Wilkes’s case in abeyance pending the Supreme Court’s resolution of Jackson and Brown, ultimately decided together in Brown v. United States, 602 U.S. 101 (2024). Applying Brown’s newly controlling “time-of-offense” rule, the court affirmed, holding that because federal and Michigan definitions matched when Wilkes committed his drug offenses, the predicates qualify under the ACCA notwithstanding later changes to federal drug schedules.

Summary of the Opinion

The court reaffirmed two core principles:

Under Brown v. United States, whether a state drug conviction qualifies as a “serious drug offense” under the ACCA is measured against the federal schedules as they existed at the time of the state drug offense—not at the time of the later federal offense or at federal sentencing.
Under the categorical approach, courts compare statutory definitions, not the facts of the prior convictions; the “realistic probability” concept from Gonzales v. Duenas-Alvarez is a tool for determining a statute’s scope, not a license to examine case-specific facts.

Because Wilkes’s Michigan cocaine offenses (1994, 2006, 2007) occurred before the federal removal of [123I]ioflupane in 2015, the state and federal definitions matched at the time of those offenses. Thus, the convictions qualify as ACCA predicates. The court therefore affirmed the district court’s application of the ACCA enhancement, while noting the district court’s misstep in invoking a “realistic probability” inquiry to the facts of Wilkes’s convictions.

Analysis

Precedents Cited and Their Influence

Brown v. United States, 602 U.S. 101 (2024): The centerpiece of this opinion. Brown confronted three competing timing rules for ACCA’s cross-reference to the Controlled Substances Act (CSA): (1) look to the federal schedules at the time of the prior state offense; (2) at the time of the later federal offense; or (3) at federal sentencing. The Supreme Court adopted the first: a state drug conviction “counts as an ACCA predicate if it involved a drug on the federal schedules at the time of that offense.” Brown emphasized ACCA’s focus on the historical seriousness of prior crimes and public-safety risk posed by recidivists. The Sixth Circuit implements that rule here.
Shular v. United States, 589 U.S. 154 (2020): Clarifies that ACCA’s “serious drug offense” inquiry is categorical and looks to the elements of the state offense by reference to CSA-defined controlled substances. The Sixth Circuit uses Shular’s framework for the state/federal overlay comparison.
Taylor v. United States, 495 U.S. 575 (1990) and Mathis v. United States, 579 U.S. 500 (2016): Foundational categorical-approach cases. They bar courts from looking to the underlying facts of prior convictions when applying categorical comparisons.
Gonzales v. Duenas-Alvarez, 549 U.S. 183 (2007): Introduces the “realistic probability” concept as a method to establish that a state statute is actually applied more broadly than its text suggests. The Sixth Circuit explains that Duenas-Alvarez helps ascertain the statute’s scope, not the defendant’s specific conduct.
McNeill v. United States, 563 U.S. 816 (2011): Supports time-fixed inquiries under ACCA. McNeill held that ACCA’s “maximum term” is determined by looking to state law as it existed at the time of the state conviction, not later changes. Brown drew on McNeill’s logic; the Sixth Circuit echoes that reasoning to reject Wilkes’s timing argument.
United States v. Clark, 46 F.4th 404 (6th Cir. 2022): A Sixth Circuit guidelines case holding that for U.S.S.G. career-offender predicates, courts look to federal and state law as they existed at the time of the prior state conviction. Although Clark arose under the Guidelines, its timing logic anticipated Brown’s ACCA holding. Wilkes conceded Clark’s force and sought to await Brown; Brown has now resolved the timing question for ACCA.
United States v. Burris, 912 F.3d 386 (6th Cir. 2019) (en banc): Reinforces the categorical approach within the Sixth Circuit and informs the overlay analysis between state and federal definitions.
United States v. Wilkes, 78 F.4th 272 (6th Cir. 2023): The panel’s earlier decision in the same case. It rejected Wilkes’s “stereoisomers” mismatch argument, concluding that federal “optical and geometric isomers” coverage for cocaine is coextensive with Michigan’s definition. That earlier holding remains intact and narrows the present dispute to the ioflupane timing issue.

Legal Reasoning

The Sixth Circuit’s analysis proceeds in two principal steps: first, it clarifies the proper categorical-approach methodology; second, it applies Brown’s time-of-offense rule to the ioflupane mismatch claim.

Correct framing under the categorical approach:
- The inquiry compares the elements of the state offense to the federal definition at issue; courts do not examine the actual facts of the prior convictions.
- The district court erred by invoking a “realistic probability” inquiry to conclude Wilkes’s prior convictions were unlikely to have involved ioflupane. As the panel explains, Duenas-Alvarez’s realistic-probability tool helps identify the scope of the state statute when it is ambiguous or overbroad on its face; it does not authorize fact-based inquiries into what the defendant actually did. That said, the error is harmless because Brown controls the outcome.
Applying Brown’s time-of-offense rule:
- Brown resolves the precise timing question presented by Wilkes: where federal law descheduled [123I]ioflupane in 2015, do prior state cocaine convictions from before 2015 cease to qualify? Under Brown, no.
- Because Wilkes committed his Michigan cocaine offenses in 1994, 2006, and 2007—years when both Michigan and federal law included ioflupane within their cocaine schedules—the state and federal definitions matched at the relevant time. That is dispositive.
- Brown rejected the arguments to measure ACCA predicates at the time of the later federal offense or at federal sentencing. It reasoned that ACCA targets the historical seriousness of prior criminal conduct to assess recidivism risk. Later changes to drug schedules do not erase the historical fact that the prior offenses involved substances the federal law then deemed controlled.

Impact

The opinion has several immediate and prospective consequences:

Settled timing rule in the Sixth Circuit under ACCA: The Sixth Circuit now applies Brown’s time-of-offense rule to ACCA “serious drug offense” analyses. Defendants cannot defeat ACCA predicates by pointing to post-offense federal descheduling (e.g., ioflupane’s 2015 removal) if their state offenses predated the change.
Not a one-way ratchet: Brown’s rule can cut both ways. If a defendant’s state drug offense occurred after federal descheduling but before the state updated its schedules, a mismatch at the time of the state offense can mean the state conviction does not qualify as an ACCA predicate. In other words, post-2015 state cocaine convictions that still swept in ioflupane (where federal law no longer did) may not count.
Guidance for district courts on the categorical approach: The opinion cautions against misusing Duenas-Alvarez’s “realistic probability” inquiry to examine case-specific facts. Courts should:
- Identify the statutory elements and the substances the state statute actually covers (using text, authoritative state case law, and other legitimate tools of statutory interpretation), and
- Compare that scope to the federal schedules at the time of the state offense, per Brown.
Harmony with Sixth Circuit Guidelines law: Although Brown governs ACCA, its time-fixed logic aligns with this circuit’s career-offender decision in Clark, which likewise looks to law at the time of the prior state conviction. Practitioners should, however, continue to treat ACCA and Guidelines questions as distinct unless a controlling authority squarely equates them.
Practical screening of ACCA predicates: Defense and government counsel will need to determine the dates of the state offenses (not just convictions), the scope of the state schedules and federal schedules on those offense dates, and whether the state statute is divisible. The key is the historical match at the time the prior offense was committed.

Complex Concepts Simplified

ACCA “serious drug offense”: Under 18 U.S.C. § 924(e)(2)(A), a prior state drug conviction qualifies if it involves manufacturing, distributing, or possessing with intent to distribute a controlled substance as defined by the federal Controlled Substances Act and carries a specified maximum penalty under state law. The question here is whether the state offense involved a substance that federal law treated as controlled at the time of the state offense.
Categorical approach: A method that compares the legal elements of the state offense to the generic federal definitions or schedules. Courts ask whether the state statute’s scope is the same as, or narrower than, the federal definition. They do not examine the specific facts of what the defendant actually did unless the statute is divisible into distinct offenses with different elements.
Realistic probability test (Duenas-Alvarez): A tool used to show that a state actually applies its statute to conduct broader than the federal definition when that breadth isn’t clear on the face of the statute. It is not a device to investigate the defendant’s underlying conduct.
Divisibility and modified categorical approach: If a statute lists alternative elements (creating multiple crimes), courts can consult a limited set of documents to identify which version the defendant was convicted of before applying the categorical comparison. That issue was not central here.
[123I]ioflupane: A radiopharmaceutical that was formerly listed on federal controlled-substance schedules and removed in 2015. After 2015, federal law no longer treated ioflupane as a controlled substance. Brown holds that later descheduling does not affect the ACCA status of earlier state offenses that involved substances then on the federal schedules.
“Time-of-offense” rule from Brown: For ACCA, the federal schedules used for the categorical comparison are those in effect when the state offense was committed. Later changes (either narrowing or broadening) are irrelevant to whether that past conviction counts.

Conclusion

United States v. Wilkes cements within the Sixth Circuit the Supreme Court’s time-of-offense rule for determining whether prior state drug convictions qualify as ACCA “serious drug offenses.” By applying Brown v. United States, the court holds that Wilkes’s Michigan cocaine convictions from 1994, 2006, and 2007 remain valid ACCA predicates because the federal and state drug schedules matched at the time he committed those offenses, notwithstanding the federal descheduling of [123I]ioflupane in 2015. The opinion also provides valuable guidance on the proper use of the categorical approach, clarifying that Duenas-Alvarez’s realistic-probability concept is about the scope of statutes—not a portal to the facts of prior crimes.

The key takeaways are clear: ACCA predicate status hinges on a historical match between state and federal definitions at the time of the prior offense, and later changes to federal drug schedules neither erase nor upgrade the seriousness of already-committed crimes. Going forward, defendants whose state offenses post-date federal descheduling may still raise viable mismatch arguments; those whose offenses pre-date such changes will generally not. Wilkes thus aligns Sixth Circuit law with Brown and streamlines ACCA litigation by fixing the timing inquiry and reinforcing strict adherence to the categorical approach.