Rejecting Relevant Conduct Triggers § 3584’s Consecutive Default—and Underdeveloped Plain-Error Appeals Are Waived

Introduction

In United States v. Cerrato-Avila, No. 24-1193 (10th Cir. Nov. 13, 2025) (unpublished), the Tenth Circuit affirmed a 72-month federal sentence imposed consecutively to a later-imposed 144-month state sentence following a guilty plea to a fentanyl-distribution conspiracy. The appeal presented two main issues:

• Procedural reasonableness: whether the district court erred by not adequately explaining its decision to impose the federal sentence consecutively to the anticipated state sentence.
• Substantive reasonableness: whether the total incarceration time (when combining federal and state terms) rendered the federal sentence unreasonable.

The panel held that the appellant waived review by inadequately briefing plain-error and substantive claims. On the merits, the court emphasized that, once the district court properly determined the state offense was not “relevant conduct,” the default rule under 18 U.S.C. § 3584(a)—that sentences imposed at different times run consecutively unless ordered otherwise—applied. The district court considered the § 3553(a) factors and adequately explained its rationale, and the modest upward variance (from an effective 60-month guideline term to 72 months) was not an abuse of discretion.

Although issued as an order and judgment and thus nonprecedential, the decision may be cited for its persuasive value under Fed. R. App. P. 32.1(a) and 10th Cir. R. 32.1(A). It carries important practice lessons on:

• The rigorous requirements of plain-error briefing on appeal.
• How a finding that state conduct is not “relevant conduct” undercuts a request for concurrent sentencing under U.S.S.G. § 5G1.3(c) and activates § 3584’s consecutive default.
• The limited scope of plea promises to recommend a sentence before the district court and their non-application to the government’s appellate advocacy.

Summary of the Opinion

The defendant pleaded guilty to conspiring to distribute and possess with intent to distribute fentanyl after an attempted sale to an undercover officer. His Presentence Investigation Report initially treated drug weights from a separate state case (involving fentanyl and methamphetamine) as “relevant conduct,” yielding a total offense level of 33 and a recommended range of 135–168 months, with a PSR recommendation of 120 months concurrent to the expected state sentence.

The district court sustained the defense’s objection to treating the state case as relevant conduct, emphasizing the 11-month temporal gap and dissimilarity. That determination reduced the total offense level to 23 and effectively set the Guidelines “range” at 60 months (reflecting a statutory minimum constraint, though the opinion does not identify the statutory source). The court then varied upward to 72 months and ordered the federal term to run consecutively to the forthcoming state sentence. About a week later, a state court imposed a 144-month term.

On appeal:

• The procedural claim—that the district court inadequately explained its decision to impose a consecutive sentence—was not preserved and was waived for inadequate plain-error briefing. On the merits, the panel found no procedural error: because the court rejected relevant-conduct treatment, U.S.S.G. § 5G1.3(c)’s concurrency directive did not apply, and § 3584(a)’s consecutive default controlled; the court also considered § 3553(a). Under Gall, that explanation sufficed.
• The substantive reasonableness challenge—casting the combined potential incarceration (up to 216 months) as “unreasonable”—was also waived for inadequate briefing and, in any event, failed on the merits. The federal term itself was modestly above the effective 60-month guideline term and was justified under § 3553(a); any additional time was attributable to the separate state sentence.
• The reply-brief claim that the government breached its plea agreement by defending the judgment on appeal was rejected: the government promised to recommend a low-end sentence to the district court—and it did. That promise did not extend to its appellate posture.

The judgment was affirmed.

Detailed Analysis

Precedents and Authorities Cited

• Gall v. United States, 552 U.S. 38 (2007): Establishes the requirement that district courts adequately explain their chosen sentence. The panel applied Gall to conclude that the district court’s explanation—rejecting relevant-conduct treatment and then weighing § 3553(a) in opting for the statutory default of consecutivity—was adequate.
• Setser v. United States, 566 U.S. 231 (2012): Confirms that district courts have discretion to decide whether a federal sentence runs concurrently with or consecutively to another sentence, including an anticipated state sentence that has not yet been imposed. The panel cited Setser to validate the district court’s authority to structure the federal sentence in relation to the expected state term.
• 18 U.S.C. § 3584(a), (b): Section 3584(a) sets a default rule that multiple terms of imprisonment imposed at different times run consecutively unless the court orders concurrency; § 3584(b) requires consideration of § 3553(a) factors. The opinion relies on § 3584’s default to explain why, after rejecting relevant conduct, the court need not separately justify deviating from concurrency: the default is consecutivity.
• U.S.S.G. § 5G1.3(c): Directs that a federal sentence should be concurrent to an anticipated state sentence when the state offense qualifies as relevant conduct to the federal offense. The district court found the state case not to be relevant conduct; therefore § 5G1.3(c)’s concurrency directive did not apply, leaving § 3584(a)’s consecutive default in place.
• United States v. Berryhill, 140 F.4th 1287 (10th Cir. 2025): Applied for the proposition that unpreserved sentencing objections are reviewed for plain error. The appellant failed to perform a prong-by-prong plain-error analysis.
• United States v. Isabella, 918 F.3d 816, 845 (10th Cir. 2019); Collins v. Diversified Consultants Inc., 754 F. App’x 714, 718 (10th Cir. 2018): Support the principle that general, conclusory invocations of “plain error” are insufficient and warrant no review; underdeveloped arguments are deemed waived.
• Bronson v. Swensen, 500 F.3d 1099, 1104 (10th Cir. 2007): Establishes that inadequately briefed arguments are waived on appeal. The panel applied Bronson to the appellant’s substantive-reasonableness claim.
• United States v. Damato, 672 F.3d 832, 838 (10th Cir. 2012): Articulates the abuse-of-discretion standard for substantive reasonableness and affirms that an upward variance supported by individualized § 3553(a) analysis can be reasonable.
• United States v. Villa-Vazquez, 536 F.3d 1189, 1196 (10th Cir. 2008); United States v. Trujillo, 537 F.3d 1195, 1201 (10th Cir. 2008): Clarify when the government breaches a plea agreement. A promise to recommend a sentence to the district court does not bar the government from defending the sentence on appeal absent explicit language to that effect.

Legal Reasoning

1) Procedural Reasonableness and the Consecutive Default

The appellant’s core procedural claim was that the district court failed to “provide its reasons” for imposing a consecutive federal sentence. Because this objection was not raised below, it triggered plain-error review. The panel held the argument waived because the appellant merely recited the plain-error standard without briefing any of its four prongs (error; that is plain; affecting substantial rights; seriously affecting the fairness, integrity, or public reputation of judicial proceedings). This failure persisted even after the government flagged the deficiency.

On the merits, the panel underscored a clean pathway: once the district court concluded the state offense was not relevant conduct, § 5G1.3(c)’s special concurrency rule dropped out. That left § 3584(a)’s default: consecutive sentences for terms imposed at different times unless the court orders concurrency. The district court then did what § 3584(b) and Gall require—considered and explained its § 3553(a) analysis. That explanation was sufficient. In other words, there is no freestanding obligation to justify “deviating” to consecutive sentences; consecutivity is the statutory baseline once relevant-conduct concurrency is off the table.

2) The Relevant-Conduct Determination

The Guidelines’ relevant-conduct framework (U.S.S.G. § 1B1.3) often looks to similarity, regularity, and temporal proximity to determine whether separate conduct is part of the “same course of conduct” or a “common scheme or plan.” The district court found an 11-month gap and dissimilarities made the state trafficking “sufficiently separate in time,” so it was not relevant conduct. That finding had two pivotal effects:

• It materially reduced the federal drug quantity and the offense level—from the PSR’s level 33 to level 23.
• It eliminated the predicate for § 5G1.3(c)’s concurrency rule, thereby activating § 3584(a)’s consecutive default.

The appellate panel accepted that reasoning and treated the district court’s explanation as adequate under Gall.

3) Substantive Reasonableness

The appellant framed the combined possible incarceration (federal 72 months plus state 144 months) as unreasonable. The panel characterized this as either:

• A reframing of the procedural challenge (in which case it fails for the reasons above), or
• A distinct substantive-reasonableness claim (in which case it was waived for inadequate briefing and meritless).

The panel emphasized two points. First, the district court imposed a modest upward variance from an effective guideline term of 60 months to 72 months and justified that variance with individualized § 3553(a) considerations. Second, the remainder of the 216-month aggregate was attributable to the separate state sentence; the federal sentence’s reasonableness is judged on its own terms.

4) Plea Agreement: No Government Breach

In reply, the appellant argued the government breached its plea agreement by defending the district court on appeal. The agreement obligated the government to recommend a sentence at the low end of the applicable Guidelines range as calculated by the court. The government did exactly that at sentencing—requesting 60 months—thereby fulfilling its promise. Absent express language, such promises do not constrain the government’s appellate arguments. The panel, citing Villa-Vazquez and Trujillo, rejected the breach claim as meritless.

Impact and Practical Implications

1) Appellate Practice: Do Not Skimp on Plain-Error Briefing

The court’s reliance on Isabella, Collins, and Bronson reiterates a hard lesson: merely invoking “plain error” will not save an unpreserved claim. Counsel must develop each prong with argument and citation. Failing to do so can forfeit even plain-error review.

2) Sentencing Structure: Consecutive Is the Baseline When Relevant Conduct Is Rejected

Cerrato-Avila is a clear reminder that § 3584(a) sets the default to consecutivity for sentences imposed at different times. If a defendant seeks concurrency based on overlapping conduct, the crucial gateway is proving that the other offense constitutes “relevant conduct.” If that gateway fails, courts are not required to provide a separate “why not concurrent” explanation. Instead, courts should:

• Explain the relevant-conduct determination, and
• Lay out an individualized § 3553(a) analysis supporting the overall sentence.

That suffices under Gall.

3) State-Federal Interplay: Anticipated State Sentences

Under Setser, judges may structure a federal sentence in anticipation of a not-yet-imposed state sentence. Practitioners should be prepared to litigate concurrency at the federal sentencing hearing itself, well before the state sentence is entered. If the state conduct is relevant, § 5G1.3(c) can drive concurrency; if not, expect the § 3584 default to carry the day.

4) Reasonableness Review Focuses on the Federal Sentence Itself

The panel’s response to the “216 months is too long” argument highlights a subtle but important point: the substantive reasonableness of a federal sentence is assessed in light of federal sentencing purposes and the federal record. Aggregate time across sovereigns generally does not render the federal term substantively unreasonable, especially where the district court provided an individualized § 3553(a) rationale and the additional time is the product of a separate state judgment.

5) Plea Agreements: Be Express About Appellate Posture

If the defense wants to limit the government’s appellate advocacy, that must be negotiated and spelled out. A promise to recommend a sentence before the district court does not imply a promise of appellate silence or concession.

Complex Concepts, Simplified

• Plain-error review: A demanding four-part standard for unpreserved errors. The appellant must show (1) error, (2) that is plain (clear/obvious), (3) affecting substantial rights (usually outcome determinative), and (4) that seriously affects the fairness, integrity, or public reputation of judicial proceedings. All four prongs must be argued and met.
• Procedural vs. substantive reasonableness:
  • Procedural concerns how the sentence was imposed (e.g., correct Guidelines calculation, considering § 3553(a), and adequately explaining the sentence).
  • Substantive asks whether the length of the sentence is reasonable in light of § 3553(a). Review is deferential; variances are permitted if supported by case-specific reasons.
• Relevant conduct (U.S.S.G. § 1B1.3): Conduct that is sufficiently related to the conviction offense to affect guideline calculations. Decisionmakers often look to similarity, regularity, and temporal proximity. If a separate offense is relevant conduct, it can increase drug weights and trigger concurrency principles under § 5G1.3(c).
• U.S.S.G. § 5G1.3(c): When the defendant faces an anticipated state sentence for conduct that is relevant to the federal offense, the Guidelines call for the federal term to run concurrently, to achieve a fair and unduplicated punishment for the same course of conduct.
• 18 U.S.C. § 3584(a), (b): Establishes that multiple sentences imposed at different times run consecutively unless the court orders concurrency; courts must consider § 3553(a). If § 5G1.3(c) does not apply, § 3584’s default fills the gap.
• Upward variance: A sentence above the advisory guideline range based on § 3553(a) factors. Such variances are reviewed for abuse of discretion and require individualized reasoning tied to the record.
• Setser authority: District courts can decide on concurrency or consecutivity relative to a state sentence that has not yet been imposed.
• Statutory minimum and the “effective guideline sentence”: When a statute sets a mandatory minimum above the calculated guideline range’s bottom, the Guidelines effectively adjust so that the minimum controls (see U.S.S.G. § 5G1.1(b)). The panel notes the “Guidelines range” as 60 months, suggesting such a constraint; the opinion does not specify the statute.

Conclusion

United States v. Cerrato-Avila offers a crisp, practitioner-focused synthesis of federal sentencing structure when a related state case is in play. The opinion teaches:

• Inadequately developed plain-error arguments are waived; appellate courts will not construct the prongs for the appellant.
• When a district court reasonably finds a state offense is not “relevant conduct,” U.S.S.G. § 5G1.3(c) no longer points to concurrency, and § 3584(a)’s consecutive default governs—so long as the court considers § 3553(a) and explains its reasoning, no additional “why consecutive” explanation is needed.
• Substantive reasonableness is assessed with respect to the federal sentence; aggregate time driven by a separate state sentence does not, without more, render the federal term unreasonable.
• Plea agreements promising a sentencing recommendation to the district court do not bar the government from defending the judgment on appeal absent explicit language.

Although nonprecedential, the decision is a persuasive reminder that concurrency arguments live or die on the “relevant conduct” gateway, that § 3584(a) sets a powerful default toward consecutivity, and that appellate success depends on disciplined, prong-by-prong plain-error briefing. Defense counsel should carefully develop the record on similarity, regularity, and temporal proximity for relevant-conduct purposes and, where concurrency is sought, present a robust § 3553(a) case; on appeal, they must fully engage the governing standards. Prosecutors and judges can look to Cerrato-Avila as a succinct roadmap for properly structuring and explaining sentences amid overlapping state and federal prosecutions.

Case Snapshot

• Court: Tenth Circuit
• Date: November 13, 2025
• Disposition: Affirmed
• Key Holdings:
  • Underdeveloped plain-error and substantive-reasonableness arguments are waived.
  • Rejection of relevant conduct removes § 5G1.3(c) from play; § 3584(a)’s consecutive default controls, with § 3553(a) explanation sufficient under Gall.
  • Upward variance to 72 months was justified and not an abuse of discretion; aggregate time is driven by the separate state sentence.
  • No government breach of plea agreement by defending the sentence on appeal where the promise was limited to a sentencing recommendation in the district court.
• Precedential Status: Unpublished (citable for persuasive value under Fed. R. App. P. 32.1(a); 10th Cir. R. 32.1(A)).