United States v. Arias-Mercedes, 901 F.3d 1

In April 2015 the Coast Guard intercepted a 20-foot vessel off Dorado, Puerto Rico, carrying 72.5 kg of cocaine and three men: Ynocencio Arias-Mercedes (defendant), Victor Mercedes-Guerrero, and Juan Concepción-García.
A federal grand jury indicted the three on drug importation and distribution conspiracy counts; Arias-Mercedes pleaded guilty to all four counts.
The PSR attributed more than 50 kg but less than 150 kg of cocaine, producing a base offense level of 34 and, after acceptance, an offense level yielding a GSR affected by a 120-month statutory minimum; the court ultimately set a GSR of 87–108 months.
The defendant sought a two-level minor participant reduction under USSG §3B1.2(b), arguing he was a mere transporter and less culpable than co-participants, and alternatively sought a downward departure/variance.
The district court denied the mitigating-role adjustment, sentenced the defendant to concurrent 87-month terms (bottom of the GSR), and the defendant appealed alleging procedural error in applying the role adjustment rules and substantive unreasonableness of the sentence.

Issue	Plaintiff's Argument (Government)	Defendant's Argument (Arias-Mercedes)	Held
Whether the district court erred in denying a minor-participant reduction under USSG §3B1.2(b) and Amendment 794	The court correctly limited the comparison universe to participants responsible for the relevant conduct (the vessel voyage) and properly found defendant not substantially less culpable than the average participant	Defendant argued he was merely a transporter, less culpable than most co-participants (and should be compared to broader conspiracy participants), and thus entitled to a two-level reduction	Affirmed: Amendment 794 does not require comparison to hypothetical or broader-conspiracy actors; the proper universe is those involved in the relevant conduct (the voyage), and the denial was not clearly erroneous because defendant was not substantially less culpable than the average participant
Whether the 87-month sentence was substantively unreasonable	Sentence at bottom of the properly calculated guideline range with a plausible §3553(a) explanation is reasonable	Defendant sought a downward variance, arguing the sentence was excessive given his role and personal circumstances	Affirmed: The district court provided a plausible sentencing rationale and the within-GSR sentence was defensible and not an abuse of discretion

Matos-de-Jesús v. United States, 856 F.3d 174 (1st Cir.) (framework for procedural/substantive review of sentencing)
Pérez v. United States, 819 F.3d 541 (1st Cir. 2016) (defendant bears burden to prove mitigating role by preponderance; review for clear error)
De la Cruz-Gutiérrez v. United States, 881 F.3d 221 (1st Cir.) (apply role reduction analysis to participants involved in relevant conduct)
Vargas v. United States, 560 F.3d 45 (1st Cir. 2009) (relevant conduct limits universe for role comparison; transporter often limited to single shipment)
Stinson v. United States, 508 U.S. 36 (1993) (treating Guidelines commentary as authoritative)
Rita v. United States, 551 U.S. 338 (2007) (reasonableness review and deference to within-GSR sentences)