Mitigating Role Requires Identifying All Discernable Participants in Relevant Conduct (Not Just the Apprehended Crew)

Case: United States v. da Conceição-Level (1st Cir. June 16, 2026)
Court: United States Court of Appeals for the First Circuit (Montecalvo, J.)
Primary Doctrine: Proper application of U.S.S.G. § 3B1.2 after United States v. Guía-Sendeme

1. Introduction

This sentencing appeal arises from a DEA sting operation targeting an international cocaine-smuggling venture. Nivaldo da Conceição Level, a Brazilian pilot, flew an aircraft carrying roughly 450 kilograms of cocaine from Venezuela to Humacao, Puerto Rico, where law enforcement seized the drugs upon landing and arrested him and a companion, Hotaciano Pereira Dos Santos.

After pleading guilty to six drug-trafficking conspiracy and importation counts, Conceição Level received a 135-month sentence. He challenged three guideline determinations:

  • a dangerous-weapon enhancement (U.S.S.G. § 2D1.1(b)(1)) based on a “large military-style hunting knife” on board;
  • denial of a mitigating-role adjustment (U.S.S.G. § 3B1.2); and
  • denial of a duress/coercion departure (U.S.S.G. § 5K2.12 (2023)).

The First Circuit affirmed the weapon enhancement and the denial of duress, but vacated and remanded because the district court’s mitigating-role analysis did not properly define the “universe of participants” under the framework clarified in United States v. Guía-Sendeme.

2. Summary of the Opinion

  • U.S.S.G. § 2D1.1(b)(1) (dangerous weapon): Affirmed. The knife’s presence on a cocaine-laden flight supported the enhancement, and the defendant did not show it was “clearly improbable” the knife was connected to the offense.
  • U.S.S.G. § 3B1.2 (mitigating role): Vacated and remanded. The district court focused largely on the two apprehended defendants and failed to account for other discernable participants involved in planning and executing the venture (including identified targets and other operational actors) as required by United States v. Guía-Sendeme.
  • U.S.S.G. § 5K2.12 (duress/coercion) (2023): Affirmed. The record supported the finding that no objectively serious threat (explicit or implicit) was shown under United States v. Sachdev.

3. Analysis

3.1. Precedents Cited

A. Sources for the factual record after a guilty plea

  • United States v. Trahan and United States v. Spinks: The court reiterated the familiar rule that, following a guilty plea, it draws facts from the undisputed PSR and relevant hearing transcripts. This matters in guideline disputes because the PSR’s uncontested narrative often becomes the factual “record” for role, weapon, and coercion analyses.

B. Standards of appellate review

  • United States v. Melendez-Hiraldo and United States v. Nieves-Mercado: These cases supply the three-tiered review framework for preserved guideline issues—clear error for factfinding, de novo for guideline interpretation/application, and abuse of discretion for judgment calls. The opinion uses this structure to separate: (i) the factual “nexus” question for § 2D1.1(b)(1), (ii) the procedural/legal sufficiency of the § 3B1.2 methodology under Guía-Sendeme, and (iii) the objective-threat determination for § 5K2.12.

C. Dangerous weapon enhancement doctrine

  • United States v. Lagasse: Establishes that once a weapon’s presence is shown in a drug case, the enhancement applies unless “special circumstances” make it “clearly improbable” that the weapon was connected to the offense. This frames the burden-shifting dynamic the defendant failed to overcome.
  • United States v. Corcimiglia: Supports the proposition that a potentially lawful or alternative reason to possess the weapon does not, standing alone, defeat the enhancement. The court used this to reject the “aviation tool” explanation as insufficient by itself.

D. Mitigating role: correcting overreadings of small-crew cases

  • United States v. Arias-Mercedes: The government relied on its language about “tiny crew” transport of large drug loads. The First Circuit treated Arias-Mercedes as context-specific rather than a categorical limitation of the participant universe. The present case shows how sentencing courts can drift into treating “tiny crew” as the entire comparison set.
  • United States v. Guía-Sendeme: The controlling analytical framework. It requires a four-step inquiry, beginning with identifying the “universe of participants” involved in the relevant conduct. The opinion applies this framework beyond maritime smuggling to aerial transport: participant identification is record-driven, not vessel-crew-driven.
  • United States v. Robles-López, United States v. Guzmán-Ceballos, and United States v. Flores-Álvarez: These post-Guía-Sendeme remands underscore the remedy for a flawed participant-universe analysis: vacatur and resentencing rather than appellate reweighing.

E. Preservation, waiver, and appellate forfeiture

  • United States v. Colón-Cordero: Guides the preservation inquiry—whether the defendant adequately alerted the district court to the nature of the claimed error.
  • United States v. Guzmán-Ceballos: Used by analogy for finding preservation where the defendant’s sentencing arguments effectively raised the procedural complaint later advanced on appeal.
  • United States v. Zannino: Cited for waiver principles; the court rejects the government’s waiver claim because the defendant’s sentencing submissions pointed to broader conspirators (“mastermind” and related case) and argued he lacked planning/control.
  • Capen v. Campbell: Supports the conclusion that an argument raised for the first time at oral argument (here, about an “explicit threat” requirement) is waived absent extraordinary circumstances.

F. Duress/coercion departure and clear-error review

  • United States v. Sachdev: Key duress precedent: § 5K2.12 covers explicit and implicit threats, but requires an objective component—whether a reasonable person in the defendant’s position would perceive a serious threat of physical injury (or similar harms). The opinion uses this to reject purely subjective fear.
  • United States v. Fitzpatrick: Defines clear error as requiring a “strong, unyielding belief” a mistake occurred; the panel applies this to uphold the district court’s duress findings.
  • United States v. Pontoo: Reinforces that where the district court’s view is “plausible,” the appellate court will not disturb it—again supporting affirmance on duress.

G. Guideline version selection

  • United States v. Harotunian: Cited to justify use of the guidelines in effect at sentencing (here, 2023). The opinion also notes that § 5K2.12 was later deleted effective November 1, 2025, but that deletion did not govern this sentencing.

3.2. Legal Reasoning

A. Weapon enhancement (§ 2D1.1(b)(1))

The court applied the guideline’s presumption: once a dangerous weapon is “present,” the enhancement applies unless the defendant shows it is “clearly improbable” the weapon was connected to the offense. The district court credited testimony from a DEA agent with piloting experience that the knife was not a typical aviation safety tool (in contrast to pocketknives, seat belt cutters, or scissors) and could be used to protect a drug load. Given the knife’s presence on an aircraft transporting hundreds of kilograms of cocaine, the panel found no clear error in concluding the defendant failed to meet the “clearly improbable” standard.

B. Mitigating role (§ 3B1.2): the participant-universe error

The core holding is procedural and methodological: the district court’s analysis effectively treated the relevant comparison set as the two apprehended defendants (pilot and onboard assistant), invoking United States v. Arias-Mercedes in a manner later clarified as overbroad by United States v. Guía-Sendeme.

Under Guía-Sendeme, step one requires identifying “the universe of participants involved in the relevant criminal activity.” That universe is derived from “relevant conduct as a whole,” including actions taken “in preparation” for the offense and in attempts to avoid detection, as captured by jointly undertaken criminal activity principles (U.S.S.G. § 1B1.3(a)(1)(B)). The record here identified multiple additional actors: the DEA targets coordinating the venture over months (including Ruíz-Patiño and López-Henao), the recruiter, and armed FARC soldiers guarding the encampments, among others. While the district court mentioned some external actors in passing, it did not incorporate them into the culpability continuum required by the four-step framework.

Because the initial participant-universe determination was flawed, the later steps—locating the “average participant” and comparing the defendant to that average—were necessarily compromised. Consistent with Robles-López, Guzmán-Ceballos, and Flores-Álvarez, the remedy is vacatur and resentencing.

C. Preservation of the mitigating-role argument

The government argued the defendant did not preserve a participant-universe challenge. The panel rejected that position because defense counsel (i) pointed to a “related case” involving an alleged “mastermind,” and (ii) argued the defendant lacked control over planning, timing, destination, and drug quantity—arguments that inherently depend on comparison to other, more culpable participants. That was enough to alert the district court to the broader-participant theory, satisfying preservation principles reflected in United States v. Colón-Cordero and consistent with United States v. Guzmán-Ceballos, while avoiding waiver concerns discussed in United States v. Zannino.

D. Duress/coercion (§ 5K2.12) and objective threat requirement

The panel affirmed the denial of a § 5K2.12 departure because the record did not show an objectively serious threat of physical injury. The defendant’s circumstances—remote jungle camp, armed presence, inability to leave easily—supported subjective fear, but United States v. Sachdev requires more: an objective showing that a reasonable person would perceive a serious threat and that the offense was committed “because of” that coercion. The PSR did not indicate weapons were directed at him, threats were made, or violence was used. The recruiter’s statement (“if he did the flight, [he] could return home”) was characterized as insistence and financial persuasion rather than a threat of physical harm. Under clear-error standards explained in United States v. Fitzpatrick and the “plausible view of the evidence” principle in United States v. Pontoo, the district court’s finding stood.

3.3. Impact

  • Extends Guía-Sendeme beyond maritime cases: The opinion confirms that the four-step mitigating-role method applies equally to aerial smuggling. Sentencing courts cannot treat “crew size” as the participant universe when the record identifies planners, recruiters, guards, facilitators, or financiers.
  • Raises the practical stakes of the PSR record: Because “participants” must be “discernable from the record,” parties will likely litigate (and probation offices will likely document) the identity and functions of upstream conspirators even when they are not co-defendants.
  • Clarifies how to preserve role arguments: The preservation holding signals that defendants need not recite Guía-Sendeme step numbers; it may suffice to argue, with record anchors, that other identifiable conspirators exercised planning/control making the defendant less culpable.
  • Confirms strictness of § 2D1.1(b)(1) and § 5K2.12 standards: “Clearly improbable” is a steep hill for weapon challenges once presence is shown, and duress claims remain bounded by objective-threat proof under Sachdev.

4. Complex Concepts Simplified

  • “Dangerous weapon enhancement” (U.S.S.G. § 2D1.1(b)(1)): If a weapon is present during a drug offense, the guideline assumes it increases danger. The defendant must show it is clearly improbable the weapon was connected to the drug activity—more than “maybe it was for something else.”
  • “Mitigating role adjustment” (U.S.S.G. § 3B1.2): A reduction for defendants who are substantially less culpable than the average participant (e.g., minimal or minor participants). After United States v. Guía-Sendeme, courts must: (1) identify all participants in relevant conduct, (2) rank them by culpability, (3) find the average participant, and (4) compare the defendant to that average using the guideline’s factors.
  • “Relevant conduct” and “jointly undertaken criminal activity” (U.S.S.G. § 1B1.3(a)(1)(B)): Sentencing accountability can include preparatory acts and efforts to avoid detection undertaken as part of the shared criminal plan—so upstream planners and facilitators can matter for § 3B1.2 even if they were not on the plane.
  • “Departure” vs. “adjustment”: An “adjustment” (like § 3B1.2) is part of the guideline calculation. A “departure” (like § 5K2.12 (2023)) is a discretionary move away from the guideline range for specified reasons (here, serious coercion/duress).
  • “Objective” vs. “subjective” threat for duress (§ 5K2.12): Feeling afraid is subjective. The guideline requires evidence that a reasonable person would perceive a serious threat of physical harm (objective), and that the crime was committed because of that threat.

5. Conclusion

United States v. da Conceição-Level is principally a § 3B1.2 methodology decision: when the record shows a broader smuggling enterprise, a sentencing court must identify and account for all discernable participants in the relevant conduct, not merely the apprehended transport crew. The First Circuit’s vacatur and remand reinforces United States v. Guía-Sendeme as the governing framework and extends it cleanly to aerial drug-importation schemes.

At the same time, the decision underscores two limits: weapon challenges face the stringent “clearly improbable” burden once a weapon is present in a drug offense, and duress departures require objective evidence of a serious threat under United States v. Sachdev, not generalized fear arising from a dangerous environment.