United States v. Porfirio Ortega, 2014 U.S. App. LEXIS 8737

DEA investigation (2010–2011) into Porfirio Ortega and associate Gabriel "Chinto" Madrigal using informant George Tutuianu and wire/intercept evidence of multiple cocaine sales and supplier contacts.
Tutuianu and others made repeated purchases from Ortega (totaling ~605 grams attributable to Ortega); DEA provided a cocaine press and observed kilogram-pressing activity with supplier "El Don."
Intercepted calls and recorded conversations discussed kilogram quantities, pricing (~$26k–$27k per kilogram), and arrangements between Ortega and El Don.
On March 25, 2011 law enforcement stopped Misael Lopez-Rico and seized 11 bricks of cocaine (two types of packaging) later analyzed into composite samples totaling ~7.2 kg.
Original analyst (Kristen Beer) was unavailable for trial; DEA analyst Peter Ausili retested composite samples, testified the substance was cocaine, and the district court admitted the physical exhibits.
Jury convicted Ortega of conspiracy to distribute five kilograms or more of cocaine; Ortega moved for acquittal and appealed, arguing insufficient evidence of responsibility for ≥5 kg and Confrontation Clause/chain-of-custody error from admission of the 7.2 kg evidence.

Issue	Plaintiff's Argument	Defendant's Argument	Held
Sufficiency of evidence that Ortega was responsible for ≥5 kg (conspiracy liability)	Ortega: He withdrew from the conspiracy after Feb 28 sale and thus cannot be held for the March 25 delivery of 7.2 kg	Government: Ortega remained a member; withdrawal is an affirmative defense and Ortega did not prove it; coconspirator acts are attributable if reasonably foreseeable	Court: Affirmed — evidence supports that Ortega did not affirmatively withdraw; he remained liable for coconspirator's reasonably foreseeable 7.2 kg delivery
Confrontation Clause / admissibility of 7.2 kg via composite samples	Ortega: Admission violated Confrontation Clause because Ausili testified about composites created by Beer (who was absent); Ausili did not test each bag individually	Government: Ausili personally retested the substances and testified; chain-of-custody gaps go to weight not admissibility; no bad faith shown	Court: Affirmed — no Confrontation violation because the testifying analyst retested and testified; chain-of-custody issues affect weight; district court did not abuse discretion

United States v. Booker, 576 F.3d 506 (8th Cir.) (standard for reviewing sufficiency of evidence)
United States v. Polk, 715 F.3d 238 (8th Cir.) (elements of drug conspiracy)
United States v. Marquez, 605 F.3d 604 (8th Cir.) (coconspirator liability for foreseeable acts)
United States v. Jackson, 345 F.3d 638 (8th Cir.) (burden to prove withdrawal by affirmative action)
United States v. Rodriguez-Ramos, 663 F.3d 356 (8th Cir.) (souring of relationship insufficient to prove withdrawal)
Smith v. United States, 133 S. Ct. 714 (2013) (Congress left burden of proving withdrawal on defendant)
Melendez-Diaz v. Massachusetts, 557 U.S. 305 (2009) (Confrontation Clause and forensic reports)
Bullcoming v. New Mexico, 131 S. Ct. 2705 (2011) (requiring testimonial analyst to testify or retest)
United States v. Johnson, 688 F.3d 494 (8th Cir.) (chain-of-custody does not by itself trigger Confrontation Clause)
United States v. Robinson, 617 F.3d 984 (8th Cir.) (review of admissibility for abuse of discretion)
United States v. Tenerelli, 614 F.3d 764 (8th Cir.) (plain-error review when Confrontation objection not raised at trial)