§3146 Failure-to-Appear Counts, When Grouped, Do Not Create “Double Counting” That Bars a §3C1.1 Obstruction Enhancement

Case: United States v. Mello (1st Cir. Jan. 7, 2026)  |  Court: United States Court of Appeals for the First Circuit

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1. Introduction

United States v. Mello is a First Circuit sentencing decision affirming a below-Guidelines term imposed after Marcus Mello pleaded guilty to fentanyl distribution and firearm charges, and later to failure to appear for trial. The opinion is noteworthy for its treatment of (i) drug-quantity proof based on messaging and shipping evidence, (ii) the constitutionality of counting juvenile adjudications in criminal history notwithstanding the absence of jury trials in juvenile court, and (iii) the interaction between a failure-to-appear conviction under 18 U.S.C. § 3146 and an obstruction enhancement under U.S.S.G. §3C1.1.

Parties and posture. The United States (Appellee) defended the district court’s Guidelines calculations and the ultimate sentence. Mello (Defendant-Appellant) challenged his sentence as procedurally and substantively unreasonable.

Background facts. Mello sold purported oxycodone (“percs”) that contained fentanyl. A customer (A.K.) died shortly after a May 8, 2020 purchase. Messages showed that even after being told A.K. died from “1 of your pills,” Mello continued selling. When arrested in July 2020, he had a loaded handgun and hundreds of blue “M 30” pills later found to contain fentanyl. He later failed to appear for his scheduled trial, evaded arrest, and pleaded guilty to all counts.

Key issues on appeal. Mello argued the district court: (1) overestimated drug quantity (including by assuming unseized pills contained fentanyl and by not excluding drugs for “personal use”); (2) overstated criminal history by counting juvenile adjudications; (3) improperly applied §3C1.1 while also imposing a sentence for § 3146 failure to appear, and wrongly denied acceptance of responsibility; and (4) wrongly denied downward departures (age; overrepresentation of criminal history). He also challenged substantive reasonableness.

2. Summary of the Opinion

The First Circuit affirmed. It held that the district court did not clearly err in its drug-quantity approximation where the calculation rested on WhatsApp messages, FedEx tracking receipts, pill photographs, and pill counts—and where random testing of seized pills supported the inference that similar pills in the same supply stream contained fentanyl. It also upheld the district court’s rejection of a “personal use” reduction.

On criminal history, the court rejected Mello’s constitutional argument that juvenile adjudications (which lack jury trials) cannot be scored, explaining there is no constitutional right to a jury trial in juvenile delinquency adjudications.

Critically, the court rejected the claimed “double counting” between the §3146 conviction and the §3C1.1 obstruction enhancement, emphasizing that the Guidelines expressly contemplate grouping the failure-to-appear count with the underlying offense and applying the obstruction adjustment within the grouped calculation. The acceptance-of-responsibility denial was also affirmed because the case was not an “extraordinary” one permitting both obstruction and acceptance adjustments.

Finally, the First Circuit found the refusal to depart (age; overrepresentation) reasonable and held the overall below-Guidelines sentence substantively reasonable given the seriousness of continuing fentanyl sales after a death, the firearm, and deterrence considerations.

3. Analysis

A. Precedents Cited

1) Standards of sentencing review

• Gall v. United States established the appellate “two-step” framework: review for procedural error first, then substantive reasonableness under an abuse-of-discretion rubric. Mello follows Gall’s sequencing and deference architecture.
• United States v. Montero-Montero, United States v. Ruiz-Huertas, and United States v. Melendez-Hiraldo supply the First Circuit’s articulation of mixed standards (de novo for Guidelines interpretation, clear error for factfinding, abuse of discretion for judgment calls) and the substantive review lens.
• United States v. Flores-Nater, United States v. Clogston, and United States v. Díaz-Lugo are used to define the “universe of reasonable sentencing outcomes” and the “plausible rationale/defensible result” test. The panel deploys this line to frame why disagreement with weight assigned to mitigating factors rarely suffices.
• United States v. Diaz-Serrano supports using the PSR and sentencing record as the factual basis following a guilty plea.

2) Drug-quantity approximation and evidentiary reliability at sentencing

• United States v. Cintrón-Echautegui anchors the preponderance standard for drug quantity and the permissibility of approximations and extrapolations, including using average weight evidence to estimate total quantities.
• United States v. Dunston and United States v. Demers emphasize that sentencing does not require “mathematical precision,” only a “reasonable approximation,” and that conservative approaches are especially attractive when evidence is imprecise.
• United States v. Rodriguez (both citations), United States v. Kinsella, and Cumpiano v. Banco Santander P.R. supply the clear-error lens: the question is whether there is evidence supporting the finding, not whether other views might undercut it.
• United States v. Sklar and United States v. Bernier support reliance on “virtually any dependable information,” including PSR material, and deference to the district court on reliability/credibility absent specific contradictions.
• United States v. Marquez and United States v. Platte illustrate accepted approximation methods based on transaction counts and typical quantities over time—cases the panel distinguishes because Mello involved contemporaneous messages and pill counts rather than conflicting recollections.
• United States v. Hilton supports extrapolating from seized/tested packages to similar unseized ones observed in the defendant’s possession.
• United States v. Concepcion-Guliam is invoked for the inference that large quantities imply distribution rather than personal use.
• United States v. Pinkham appears for the proposition (not definitively adopted in the First Circuit) that some circuits exclude personal-use drugs from drug-quantity calculations; Mello uses it, but the panel finds no factual basis for exclusion here and applies plain-error review to an unpreserved personal-use theory as to oxycodone.

3) Juvenile adjudications and constitutional limits on criminal history scoring

• United States v. Tavares and United States v. Gonzalez-Arimont confirm the Guidelines contemplate counting certain juvenile adjudications.
• United States v. Unger (and the uncounseled-conviction line) frames when prior adjudications are excluded as “constitutionally infirm.”
• Burgett v. Texas supplies the core rule that convictions obtained in violation of the Sixth Amendment right to counsel cannot be used to enhance punishment later.
• United States v. Ponzo and United States v. Barbour support the allocation of burdens: once the government shows the conviction exists, the defendant must show constitutional infirmity.
• Bellotti v. Baird (citing McKeiver v. Pennsylvania) is the doctrinal pivot: juveniles are not constitutionally entitled to jury trials in delinquency adjudications, so the absence of a jury is not an infirmity.
• United States v. Zannino is cited to deem an undeveloped due process theory waived.

4) Obstruction, acceptance of responsibility, and grouping mechanics

• United States v. Soto-Sanchez and United States v. Rathbun govern unpreserved claims and the necessity of engaging the plain-error standard on appeal.
• United States v. McCarthy and United States v. Langston stress the defendant’s burden and the substantial deference owed to the district court’s acceptance-of-responsibility determinations.
• United States v. Maguire supplies the First Circuit’s high bar for “extraordinary cases” permitting both obstruction and acceptance (“hen’s-teeth rare”) and supports denying acceptance where obstruction undermines sincerity.
• United States v. McLaughlin and United States v. D'Angelo support the relevance of bond compliance/timeliness and reiterate that a guilty plea does not entitle a defendant to acceptance credit.
• United States v. Stile supports denying acceptance where the defendant obstructed the prosecution despite pleading guilty.

5) Departures, variances, and the scope of appellate review in the advisory-Guidelines era

• United States v. Herman and United States v. Anonymous Defendant are central to the panel’s clarification that (post-Booker) discretionary refusals to depart are reviewable for reasonableness; the older “no jurisdiction” notion is treated as ill-fitting in the advisory regime.
• United States v. Kornegay and United States v. Romolo are discussed as the lineage of the earlier approach, which the court explains has been overtaken by advisory-Guidelines reasonableness review.
• United States v. Hernández is cited for applying the Guidelines in effect at the time of sentencing.
• United States v. Fletcher and United States v. Santini-Santiago provide the practical maxim that “a departure is just a variance by another name,” which the panel uses to contextualize the district court’s treatment of age under § 3553(a).
• The court also relies on the Sentencing Commission’s rulemaking explanation in Sentencing Guidelines for United States Courts, 90 Fed. Reg. 19798 regarding the 2025 removal of many departure provisions and the expectation of “outcome neutral” migration to variances.

6) Substantive reasonableness and disparity arguments

• United States v. Sansone, United States v. Rivera-Morales, and United States v. King reinforce deference to district courts and the difficulty of challenging a below-range sentence as too high.
• United States v. De Jesús-Torres and United States v. Pacheco-Martinez illustrate affirmances where courts weighed youth/mental health against offense seriousness.
• United States v. Reyes-Santiago, United States v. Rosario, and United States v. Jiménez supply the “apples to apples” principle for disparity claims and reject reliance on bare national medians without comparability details.
• United States v. Ayala-Landor similarly rejects a disparity argument where criminal history and characteristics explain a variance from national statistics.
• United States v. Ortiz-Pérez and United States v. Dávila-González are used to explain that a court’s failure to expressly address every argument does not show it was ignored, especially where the court states it considered all § 3553(a) factors.

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B. Legal Reasoning

1) Drug quantity: using messaging and shipment evidence to approximate unseized fentanyl pills

The court upheld a drug-quantity calculation attributing to Mello roughly 11,000 pills discussed in WhatsApp communications with a supplier (“Chop”), plus ten oxycodone pills seized at arrest, yielding 3,022.96 kilograms of “converted drug weight” (CDW) and a base offense level of 32. Two doctrinal moves matter:

• Reliability at sentencing is broad. The court treated the WhatsApp messages, attached photos, FedEx tracking information, and contemporaneous pill counts as “dependable information” supporting PSR findings. Mello offered no specific contradictions or reasoned attack on authenticity/accuracy, so the district court did not abuse its discretion in relying on them.
• Inference from tested pills to untested pills is permissible. Given repeated seizures and random testing confirming fentanyl in the same distinctive blue “M 30” pills, and given the temporal linkage between shipments, sales, and seized inventory, the inference that the broader lot contained fentanyl was held “reasonable,” not speculative.

The panel also emphasized a methodological restraint: the PSR did not “double count” pills sold to A.K. or the CI or seized at arrest as separate additions if they were already captured in the shipment-based estimate. That feature helped justify the approximation as fair and record-grounded.

2) “Personal use” exclusions: factual support is required, and preservation matters

Mello argued that drug quantity should be reduced for personal consumption. The panel’s reasoning was straightforward: personal-use exclusion (even if available) depends on facts, not general history of addiction. For fentanyl pills, admissions suggested he stopped opiates in March 2020 and the packaging/quantity suggested distribution. For the oxycodone pills, the argument was not preserved below, triggering plain-error review and dooming the claim in light of baggie packaging and the same “not using opiates” narrative.

3) Juvenile adjudications: no jury in juvenile court is not a “constitutional infirmity”

Mello’s constitutional attack tried to analogize nonjury juvenile adjudications to uncounseled convictions. The First Circuit rejected the analogy at the threshold: unlike the right to counsel, there is no constitutional entitlement to a jury trial in juvenile delinquency proceedings (Bellotti/McKeiver). Without an underlying constitutional entitlement, there is no constitutional infirmity to cure, and the Guidelines’ explicit inclusion of qualifying juvenile adjudications stands.

4) The opinion’s central clarifying move: §3146 + §3C1.1 is not improper “double counting” because the Guidelines require grouping and internalize the adjustment

Mello’s most structurally important argument was that punishing the same failure-to-appear conduct via (i) a § 3146 conviction (with a consecutive term) and (ii) a §3C1.1 obstruction enhancement “double counted,” akin to the Guidelines’ bar on pairing certain firearm enhancements with a § 924(c) conviction.

The First Circuit rejected this by explaining how the Guidelines are designed to handle failure-to-appear cases:

• Grouping rule controls. When a defendant is convicted of both failure to appear and the underlying offense, the counts are grouped under U.S.S.G. §3D1.2(c) and §2J1.6 commentary. The offense level becomes the underlying offense level plus the §3C1.1 two-level increase (or the obstruction offense level, if higher).
• No § 924(c)-style problem exists. The §2K2.4 commentary’s double-counting prevention is necessary because § 924(c) is excluded from grouping and requires a mandatory consecutive sentence. By contrast, § 3146 does not carry a mandatory minimum, is grouped, and the Guidelines explicitly integrate obstruction conduct into the grouped calculation and then direct apportionment among counts. In short: the system already accounts for how to avoid punitive stacking in this setting, and the district court followed that system.

5) Acceptance of responsibility: obstruction makes “extraordinary” cases rare

Once obstruction applies, §3E1.1 credit becomes exceptional. The panel held that childhood trauma, mental health struggles, and pretrial rehabilitation did not transform this case into the “extraordinary” category, particularly where Mello absconded on the trial date, avoided arrest, and pleaded guilty only after being caught. The district court’s sincerity assessment was treated as quintessentially discretionary and well supported.

6) Departures and variances: reasonableness review and the post-2025 departure landscape

The court reviewed the discretionary denial of departures for reasonableness, consistent with United States v. Anonymous Defendant and United States v. Herman. On age, it found no error in declining a formal departure because Mello’s age did not present “to an unusual degree,” while still considering age as a § 3553(a) factor. Notably, the panel treated the Sentencing Commission’s 2025 deletion of most departure provisions as confirmatory context: many departure facts can and will be handled as variances, with expected outcome neutrality.

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C. Impact

• Failure-to-appear prosecutions: a clearer “no double counting” roadmap. Mello reinforces that when § 3146 is charged alongside the underlying offense, the Guidelines’ grouping mechanism (and the built-in §3C1.1 increase) is the intended structure, and defendants should not expect a § 924(c)-type bar to the obstruction enhancement.
• Digital supply-chain evidence at sentencing. The opinion is a practical template for treating messages, shipment tracking, photos, and contemporaneous pill counts as sufficiently reliable to approximate drug quantity—especially when random testing of seized samples corroborates the nature of the product stream.
• Juvenile history challenges narrowed. The court forecloses (at least in this circuit) a broad constitutional argument that juvenile adjudications are unusable because they lacked juries; challenges must instead identify an actual constitutional entitlement (e.g., counsel) and a denial of that entitlement.
• Age/brain-development mitigation will often be addressed as variance arguments. While Mello applies the pre-2025 Guidelines, it signals that age-based mitigation is unlikely to require a formal “departure” rubric and is comfortably evaluated within § 3553(a), particularly after the Sentencing Commission’s removal of many departure provisions.

4. Complex Concepts Simplified

• Converted Drug Weight (CDW). A Guidelines tool that converts different drugs into a common unit using conversion ratios, enabling a single offense level to be set across drug types.
• Grouping (U.S.S.G. §3D1.2). A method for combining related counts so the Guidelines produce one coordinated offense level rather than stacking punishment count-by-count. In failure-to-appear cases, grouping is designed to incorporate the obstructive conduct into the combined calculation and then “apportion” the total sentence among counts.
• Obstruction enhancement (U.S.S.G. §3C1.1). A two-level increase for conduct like willfully failing to appear for a judicial proceeding.
• Acceptance of responsibility (U.S.S.G. §3E1.1). A reduction for genuine, timely contrition. If obstruction applies, acceptance is normally denied unless the case is “extraordinary.”
• Departure vs. variance. A “departure” is a Guidelines-identified basis to move away from the range; a “variance” is a statutory § 3553(a) decision to sentence outside the range. Mello underscores that, in practice, both are reviewed for overall reasonableness in the advisory-Guidelines era.
• Plain error vs. preserved error. If a defendant did not raise an issue in the district court, appellate review is much harder: the error must be clear/obvious and affect substantial rights, among other requirements.

5. Conclusion

United States v. Mello affirms a below-Guidelines sentence while clarifying several recurring sentencing disputes. Most notably, it rejects the “double counting” challenge to applying U.S.S.G. §3C1.1 where the defendant is also convicted under 18 U.S.C. § 3146, explaining that the Guidelines’ grouping and apportionment rules are expressly built to handle that overlap. The decision also reinforces the permissibility of drug-quantity approximations grounded in reliable digital communications and shipment evidence, confirms that juvenile adjudications may be scored despite the absence of jury trials in juvenile court, and illustrates the high bar for receiving acceptance-of-responsibility credit after obstructive conduct. In combination, these holdings strengthen district courts’ discretion to synthesize modern evidentiary sources at sentencing while adhering closely to the Guidelines’ structural directives for grouped obstruction-related offenses.