A. Precedents Cited

1) Appellate sentencing framework and standards of review

• Gall v. United States: Supplies the two-step approach—procedural reasonableness first, then substantive reasonableness—anchoring the panel’s method for reviewing Mello’s claims.
• United States v. Montero-Montero: Confirms abuse-of-discretion review for preserved sentencing claims.
• United States v. Ruiz-Huertas: Provides the “mixed” standard—de novo for Guidelines interpretation/application, clear error for factfinding, and abuse of discretion for judgment calls.
• United States v. Melendez-Hiraldo: Frames substantive reasonableness review under the abuse-of-discretion rubric once procedural soundness is satisfied.
• United States v. Flores-Nater, United States v. Clogston, and United States v. Díaz-Lugo: Supply the “universe of reasonable sentencing outcomes” and the “plausible rationale/defensible result” phrasing that the panel ultimately uses to uphold the sentence.
• United States v. Diaz-Serrano: Establishes the source of facts post-plea—PSR and sentencing record.

2) Drug-quantity approximation, reliability, and clear error

• United States v. Cintrón-Echautegui: Central to the drug-quantity holding. It permits approximation by a preponderance and authorizes reasonable inferences from the sentencing record; the panel analogizes Mello’s pill-weight extrapolation to Cintrón’s capsule-weight methodology.
• United States v. Dunston and United States v. Demers: Provide the governing principle that sentencing does not require mathematical precision, only a reasonable approximation. The panel distinguishes these “conservative estimate” cases as responses to conflicting testimony—conflicts absent in Mello’s real-time digital pill counts.
• United States v. Rodriguez (115 F.4th 24) and United States v. Kinsella: Supply the clear-error lens for quantity factfinding—appellate review asks whether “any evidence” supports the finding, not whether contrary views exist.
• United States v. Rodriguez (731 F.3d 20) and Cumpiano v. Banco Santander P.R.: Reinforce the high bar for reversal (“strong, unyielding belief” of mistake) and support deference to district-court determinations about evidentiary sufficiency and inferences.
• United States v. Sklar and the PSR principle (also cited through United States v. Cintrón-Echautegui): Permit reliance on “virtually any dependable information,” including PSRs, which is crucial where the evidence consists of messages and shipping receipts rather than seized drugs.
• United States v. Bernier: Used to reject generalized reliability attacks that lack “specific contradiction or implausibility”—mirroring the panel’s view that Mello offered only “say-so” to challenge WhatsApp evidence.
• United States v. Marquez and United States v. Platte: Illustrate common transaction-based estimation methods; the panel uses them to show that Mello’s case was even stronger because it had contemporaneous statements, not retrospective recollections.
• United States v. Hilton: Supports extrapolating from tested/seized exemplars to similar unseized items—directly analogous to using tested fentanyl pills to infer the composition of similar shipped “M 30” pills.
• United States v. Hernández: Cited for applying the Guidelines in effect at sentencing (relevant because the Commission later removed most departure provisions effective Nov. 1, 2025).
• United States v. Concepcion-Guliam: Though a trial case, it supports the inference that quantity can imply distribution rather than personal use—used to rebut Mello’s personal-use argument.
• United States v. Pinkham: Acknowledges the broader circuit concept that personal-use drugs may be excluded, but the panel uses Pinkham primarily to impose plain-error review where the argument was not preserved.

3) Juvenile adjudications and constitutional constraints

• United States v. Tavares and United States v. Gonzalez-Arimont: Establish that the Guidelines contemplate counting qualifying juvenile adjudications, supporting the district court’s baseline inclusion.
• United States v. Unger: Provides the framework for excluding constitutionally infirm prior adjudications (in Unger, uncounseled issues). The panel uses it to show Mello must first demonstrate entitlement to the constitutional protection he claims was denied.
• Burgett v. Texas: The foundational rule that convictions obtained in violation of the Sixth Amendment right to counsel cannot be used to enhance punishment; it anchors why only “constitutional infirmities” matter.
• United States v. Ponzo and United States v. Barbour: Assign the burden to the defendant to show constitutional infirmity once the government proves the prior adjudication exists.
• Bellotti v. Baird (citing McKeiver v. Pennsylvania): The decisive rebuttal to Mello’s jury-trial theory—juveniles have no constitutional entitlement to a jury in delinquency adjudications, so the absence of a jury is not an infirmity.
• United States v. Zannino: Used to refuse an undeveloped due process theory—underscoring that appellate courts will not construct arguments for litigants.

4) Obstruction, acceptance of responsibility, and preservation

• United States v. Soto-Sanchez: Governs plain-error review for an unpreserved obstruction challenge and is also used to deem a departure argument waived where plain error is not addressed on appeal.
• United States v. Rathbun: Supports the idea that failing to argue the plain-error standard can itself be waiver (though the panel still addresses the merits).
• United States v. McCarthy and United States v. Langston: Establish the defendant’s burden for § 3E1.1 and the “substantial deference” owed to the district court’s acceptance determination.
• United States v. Maguire: The controlling “hen’s-teeth rare” description of “extraordinary cases” where both obstruction and acceptance apply; it guides the conclusion that Mello’s case is not extraordinary.
• United States v. McLaughlin: Cited through Langston for the proposition that bond noncompliance is “highly relevant” to sincerity of contrition.
• United States v. D'Angelo and the Guidelines commentary: Reinforce that a guilty plea does not entitle a defendant to acceptance credit.
• United States v. Stile: Supports denial of acceptance even after a guilty plea where the defendant obstructed prosecution efforts.
• United States v. Hunter and United States v. Rosas: Used to counter the “additional punishment” narrative—lack of acceptance credit is not an extra sanction for the same conduct but a failure to earn a mitigating adjustment.

5) Departures vs. variances and reviewability after Booker

• United States v. Herman and United States v. Anonymous Defendant: Key to the panel’s approach that “discretionary refusal to depart” is reviewable for “reasonableness” in the advisory system; this undercuts older jurisdictional rhetoric.
• United States v. Kornegay and United States v. Romolo: Presented by the government for nonreviewability, but the panel distinguishes their pre-Booker lineage.
• United States v. Booker: The doctrinal pivot—because the Guidelines are advisory, appellate reasonableness review expands and strict “no jurisdiction” departure doctrines lose force.
• United States v. Fletcher and United States v. Santini-Santiago: Condense the modern reality—“a departure is just a variance by another name”—supporting the panel’s tolerance for handling age through § 3553(a) rather than a formal departure.

6) Substantive reasonableness, disparity claims, and deference

• United States v. Sansone and United States v. Clogston: Emphasize that disagreement with the weight assigned to mitigation does not equal unreasonableness; weighting is largely for the district court.
• United States v. Rivera-Morales: Reinforces “significant deference” to the district court’s balancing of § 3553(a).
• United States v. King (quoted via Herman): Supplies the “rare below-the-range sentence” principle—making Mello’s substantive challenge particularly hard.
• United States v. De Jesús-Torres and United States v. Pacheco-Martinez: Support affirmance where district courts weigh age/mental health against seriousness and deterrence.
• United States v. Reyes-Santiago, United States v. Rosario, and United States v. Demers: Govern disparity arguments—comparators must be “apples to apples,” and material differences defeat the claim.
• United States v. Jiménez and United States v. Ayala-Landor: Reject reliance on national sentencing medians without offender- and offense-specific context.
• United States v. Ortiz-Pérez and United States v. Dávila-González: Reinforce that courts need not address every argument explicitly; a statement that § 3553(a) factors were considered carries weight and omissions can indicate unpersuasiveness rather than neglect.

B. Legal Reasoning

1) Drug quantity: “reasonable approximation” built on digital logistics and tested exemplars

The court’s reasoning turns on the interplay of (i) evidentiary reliability at sentencing and (ii) permissible inference in estimating quantities not seized. The district court relied on WhatsApp messages between Mello and “Chop,” photographs of FedEx tracking receipts, and Mello’s own “real-time” pill counts (including references to “3k” and “5k” shipments). Those records were bolstered by later seizures and testing: pills sold to A.K., pills sold to a CI, and pills seized at arrest all tested as fentanyl.

From that combination, the panel approved two inferential steps as reasonable, not speculative: (1) the shipments described in messages were the source of the same type of blue “M 30” pills later seized/tested; and (2) the average weight and tested composition of exemplar pills could be extrapolated to the unseized pills described in the messages. The panel also stressed the absence of conflicting evidence—Mello offered no concrete contradiction, only the possibility that “some pills” might have been different.

2) Personal use: factual findings and preservation rules

As to fentanyl pills, the district court found Mello was not using opiates/fentanyl during May–July 2020, supported by his own statements and by distribution indicators (large quantity and packaging). As to the ten white pills, the panel applied plain-error review because Mello did not preserve a personal-use argument; given packaging and Mello’s disavowal of opiate use, there was no “plain” error in including them.

3) Juvenile adjudications: “no jury right” is not “constitutional infirmity”

The panel separated two ideas: (i) some constitutional defects (like denial of counsel) can prevent use of a prior adjudication to enhance later punishment; but (ii) only defects involving protections to which the defendant was constitutionally entitled count. Because Bellotti v. Baird and McKeiver v. Pennsylvania foreclose a constitutional jury-trial right in juvenile delinquency proceedings, Mello could not recharacterize nonjury adjudications as constitutionally infirm. Thus, Guidelines-based scoring under U.S.S.G. § 4A1.2(d)(2) stood.

4) Obstruction + § 3146 conviction: grouping rules eliminate “double counting” concerns

The most jurisprudentially “clean” point in the opinion is how the panel uses the structure of the Guidelines—rather than equitable instincts—to answer the alleged double-counting. When § 3146 failure-to-appear is convicted alongside the underlying offense, the Guidelines direct grouping under § 3D1.2(c) and instruct that the combined offense level is the underlying offense level increased by the § 3C1.1 obstruction adjustment (or the obstruction offense level if higher), with the “total punishment” then apportioned across counts. In other words, the enhancement is part of the group calculation; the separate § 3146 count largely affects allocation mechanics, not an additional cumulative increase in the guideline range beyond what obstruction already produces.

The panel contrasts this with § 924(c), which is excluded from grouping and carries a mandatory consecutive minimum—hence the special anti-double-counting rule in U.S.S.G. § 2K2.4 cmt. n.4 (weapon enhancement barred). Because § 3146 is treated differently by the Guidelines’ grouping architecture, the analogy fails.

5) Acceptance of responsibility: “extraordinary case” threshold not met

With obstruction established, acceptance becomes “hen’s-teeth rare.” The panel accepted the district court’s balancing: Mello’s traumatic background, mental health, and earlier treatment efforts were real mitigation, but they did not overcome his willful flight on the eve of trial, his continued evasion, and the fact that his plea came only after re-arrest. The timing and obstructive behavior undermined the sincerity component embedded in § 3E1.1.

6) Departures and variances: reasonableness review in the advisory era

The panel treated departure denials as reviewable for reasonableness (rather than categorically unreviewable), aligning with the post-Booker logic of United States v. Anonymous Defendant. On age, the district court recognized brain-development research but found Mello’s age not unusual for Guidelines cases, and it nevertheless considered age under § 3553(a) when varying downward. The panel also noted the Sentencing Commission’s 2025 removal of many departure provisions as supporting the practical move to handle such factors through variances.

7) Substantive reasonableness: strong deference plus below-range sentence

The district court articulated multiple aggravators: the quantity, the firearm, the continuation of sales after learning that a customer died, failure to appear, and deterrence in the local drug community. It also expressly credited mitigation and imposed a significant below-Guidelines variance. Under First Circuit doctrine, a defendant challenging a below-range sentence faces a steep climb; Mello’s disagreement with the variance’s magnitude was not enough.

C. Impact

• Sentencing proof in fentanyl-pill cases: The decision reinforces that prosecutors can establish large pill quantities through authenticated digital communications and shipping records, especially when at least some exemplars are seized and tested, enabling extrapolation. Defense counsel, correspondingly, must produce more than hypothetical doubt (e.g., evidence of variability in pill sources, composition, or independent testing) to force “conservative” reductions.
• Failure-to-appear charging decisions: By rejecting the “double counting” attack, the opinion reduces the leverage of arguments that a § 3146 count should preclude § 3C1.1. In practice, defendants should expect obstruction enhancements to remain on the table even when failure to appear is separately charged, because the Guidelines expressly coordinate the two via grouping.
• Juvenile record litigation: The panel’s constitutional discussion makes clear that “no jury in juvenile court” is not a viable basis to bar juvenile adjudications from criminal history scoring. Challenges must focus on actual constitutional infirmities (e.g., counsel, waiver, due process violations) and be developed.
• Departure doctrine continues to converge with variances: The court’s reliance on the conceptual equivalence of departures and variances, and its discussion of the Commission’s 2025 amendments, will likely encourage litigants to frame mitigation primarily through § 3553(a) even when older departure language appears in the (then-applicable) manual.