United States v. Vazquez-Larrauri, 778 F.3d 276

Ismael Vázquez-Larrauri was convicted after a nine-day jury trial of leading a multi-year drug-trafficking conspiracy in Puerto Rico public housing projects and of conspiring to possess firearms in furtherance of the drug conspiracy; jury found specific drug-quantity findings on Counts II–V and found conspiracy on Count I.
Prosecution relied heavily on three cooperating witnesses (L.O., J.S., F.R.) who testified as to Vázquez's leadership, large-scale drug distribution, use/storage of firearms, and orders to kill rivals (three murders testified to).
Law enforcement testimony, wiretaps, controlled buys, and seizures provided corroboration; Vázquez presented no witnesses.
District court sentenced Vázquez to concurrent life terms on all six counts; he appealed alleging prosecutorial misconduct (vouching, burden-shifting, misstated evidence), evidentiary errors (murders, leading questions), sentencing errors (no individualized drug-quantity finding; life term on firearm count exceeds statutory maximum), and ineffective assistance of counsel.
First Circuit affirmed convictions and life terms on the five drug counts, rejected prosecutorial/evidentiary claims (largely as not plain or not prejudicial), declined to resolve ineffective-assistance claim on direct appeal, but remanded to reduce Count VI (firearm conspiracy) to the statutory maximum of 20 years.

Issue	Vázquez's Argument	Government's Argument	Held
Prosecutorial vouching for witness L.O.	Prosecutor improperly vouched by stating "I submit to you she was" truthful	Statement was ambiguous/permissible argument about credibility and jury evaluation; not clear personal assurance	No clear or obvious vouching; claim rejected
Prosecutor commented on defendant's silence	Rebuttal statement implied jury should infer against Vázquez for not testifying	Context shows prosecutor meant to rebut defense's claim that only three witnesses mattered; jury instructions protected defendant	Not improper in context; even if ambiguous, not plain error
Admission of testimony about murders (Rule 403)	Testimony about murders was unfairly prejudicial and should have been excluded	Murder testimony was highly probative of how conspiracy operated and Vázquez's leadership; limited and non-graphic	Admission not an abuse of discretion or plain error; probative value outweighed prejudice
Sentencing: failure to make individualized drug-quantity finding	District court failed to make required individualized finding for drug quantity under Guidelines	PSR was unobjected-to and supported large quantities; jury's findings alone would have yielded same Guidelines max	Error was clear but harmless on plain-error review because unchallenged PSR and jury findings would still produce life guideline range

United States v. Rodríguez-Soler, 773 F.3d 289 (1st Cir.) (discussing presentation of facts when sufficiency not challenged)
United States v. Pérez-Ruiz, 353 F.3d 1 (1st Cir.) (improper vouching doctrine)
United States v. Vizcarrondo-Casanova, 763 F.3d 89 (1st Cir.) (line between permissible credibility argument and vouching)
United States v. Hansen, 434 F.3d 92 (1st Cir.) (permissible argument re: plea agreement and credibility)
United States v. Colón-Solís, 354 F.3d 101 (1st Cir.) (requirement of individualized drug-quantity finding)
United States v. Pizarro, 772 F.3d 284 (1st Cir.) (drug-quantity finding standard for Guidelines)
United States v. Almonte-Nuñez, 771 F.3d 84 (1st Cir.) (remedy for sentences exceeding statutory maximums)
Strickland v. Washington, 466 U.S. 668 (constitutional standard for ineffective assistance)
United States v. Sepulveda, 15 F.3d 1161 (1st Cir.) (context in assessing prosecutor's remarks)