United States v. Rodrigo Alvarez-Quinonez, 22-30161

Defendant Rodrigo Alvarez-Quinonez was convicted of conspiracy to distribute controlled substances and possession of fentanyl with intent to distribute.
On appeal he challenged admission of transcripts of intercepted phone calls and text messages and lay-opinion identification of him as a speaker on those calls.
The lead DEA agent authenticated transcripts despite not being familiar with Alvarez-Quinonez’s voice; the agent relied on the defendant’s on-record self-identification in a January 22, 2020 call and matching of transcripts to physical surveillance.
The agent also testified as a lay witness identifying the speaker based on the totality of the investigation; another DEA agent testified as an expert about drug code words and trafficking practices.
The district court admitted the transcripts under Federal Rule of Evidence 901 and allowed the lay-opinion identification under Rule 701; the Ninth Circuit affirmed.

Issue	Plaintiff's Argument	Defendant's Argument	Held
Authentication of transcripts (Fed. R. Evid. 901)	Transcripts can be authenticated by evidence other than voice familiarity; Rule 901 low threshold satisfied by investigation linkages	Agent not familiar with defendant’s voice, so could not authenticate transcripts	Affirmed — defendant’s self-identification plus matching transcripts to surveillance met Rule 901’s authentication threshold
Lay-opinion identification (Fed. R. Evid. 701)	A law-enforcement lay witness may identify a speaker based on personal knowledge and facts learned during the investigation	Agent lacked personal voice familiarity and did not personally observe all investigative steps, so cannot form permissive lay opinion	Affirmed — agent’s investigative knowledge permitted lay-opinion ID; specialized-code-word testimony came from an admitted expert, so no improper reliance on specialized knowledge

United States v. Seminole, 865 F.3d 1150 (9th Cir. 2017) (de novo review of district court construction of evidentiary rules)
United States v. Pang, 362 F.3d 1187 (9th Cir. 2004) (standard for evaluating foundation for audio evidence)
United States v. Gadson, 763 F.3d 1189 (9th Cir. 2014) (voice identification and scope of lay-opinion testimony by investigators)
Vatyan v. Mukasey, 508 F.3d 1179 (9th Cir. 2007) (Rule 901 low-threshold for authentication)
United States v. Ortiz, 776 F.3d 1042 (9th Cir. 2015) (probative value for authenticated evidence is for the jury)
United States v. Workinger, 90 F.3d 1409 (9th Cir. 1996) (authentication burden and jury’s role in weighing probative value)
United States v. Freeman, 498 F.3d 893 (9th Cir. 2007) (law-enforcement lay witnesses may rely on investigative facts and experience)