United States v. Matta-Quiñones (1st Cir. 2025): The “Un-Flagging Duty” to Probe Case-Agent Contact with Deliberating Jurors

Introduction

On 9 June 2025 the United States Court of Appeals for the First Circuit vacated two gun-possession convictions and the resulting revocation sentence of Luis Javier Matta-Quiñones. The ruling is noteworthy not because the evidence was thought insufficient—as the court squarely rejected that argument—but because the trial judge failed to investigate jury-agent contact that occurred during deliberations.

At trial in the District of Puerto Rico, jurors asked to view the firearms and ammunition. The district judge—applying a local rule that left firearms in FBI custody—required the FBI case agent to be physically present while jurors inspected the items. Defense counsel objected to the agent’s presence, worried about the influence on jurors, but the court overruled the objections. After conviction, the defense moved for a new trial, arguing juror misconduct. The trial court denied the motion, finding any contact “brief and de minimis.” On appeal, the First Circuit concluded that the mere potential for improper influence created a colorable claim of juror misconduct and, because no inquiry at all was undertaken, the convictions had to be vacated.

Summary of the Judgment

Convictions vacated. Possession of firearms and possession of a machinegun (§§ 922(g), (o)) were set aside; the government may retry because the evidence was otherwise sufficient.
Revocation sentence vacated. The district court had relied on the now-vacated convictions to impose an 18-month consecutive term.
Key holding. When a defendant raises a plausible claim that an interested party (here, the prosecution’s case agent) interacted with a deliberating jury, the trial court has an “un-flagging duty” to conduct a reasonable inquiry. Failure to do so is reversible error.
Secondary holdings. The panel (a) clarified the sufficiency standard for proving possession and knowledge of a machinegun’s automatic capability, and (b) flagged two evidentiary missteps—use of an FBI 302 for impeachment and exclusion of a probation “Receipt for Property”—that should be avoided on retrial.

Analysis

1. Precedents Cited and Their Influence

Turner v. Louisiana, 379 U.S. 466 (1965) – foundational case condemning continuous association between government witnesses and a sequestered jury.
Remmer v. United States, 347 U.S. 227 (1954) – established courts’ duty to investigate alleged external influence on jurors.
United States v. Gastón-Brito, 64 F.3d 11 (1st Cir. 1995) & United States v. Zimny, 846 F.3d 458 (1st Cir. 2017) – First Circuit cases requiring an “adequate inquiry” when colorable juror-misconduct claims arise.
United States v. Pittman, 449 F.2d 1284 (9th Cir. 1971); United States v. Florea, 541 F.2d 568 (6th Cir. 1976); United States v. Freeman, 634 F.2d 1267 (10th Cir. 1980) – considered persuasive; each condemned sending a prosecution agent or witness into the jury room and suggested that such contact warrants a new trial.

By weaving these strands together, the panel reinforced that trial judges in the First Circuit cannot treat case-agent participation as a benign “safety” measure. Even silent, brief, and court-approved contact raises the specter of undue influence and demands fact-finding.

2. The Court’s Legal Reasoning

Preservation of the objection. The First Circuit parsed the sidebar transcript and concluded that defense counsel twice objected to the agent’s presence, alerting the judge to the very risk now asserted. Therefore, ordinary abuse-of-discretion review applied, not plain-error.
Colorable misconduct. A prosecution agent, already identified with one party, was placed in the trusted role of assisting jurors outside the presence of counsel or the defendant—“friend of the jury” status forbidden by the adversary model.
Failure to investigate. Binding circuit precedent (e.g., Zimny, Gastón-Brito) obliges the district court to question the agent, jurors, or court officers. No inquiry occurred; the trial court simply assumed compliance with its “keep your mouth shut” directive.
Remedy. Because time had passed and potential prejudice would now be unknowable, a remand for belated hearings was impractical. The court therefore vacated and ordered a new trial.

3. Broader Impact

The decision is likely to reverberate across federal practice:

Case-agent protocol. Trial courts in the First Circuit must either (a) keep interested agents completely away from deliberating jurors or (b) document an explicit stipulation and inquiry showing harmlessness.
Limiting local rules. Local “sensitive-evidence” rules (e.g., D.P.R. L.R. 123) cannot override Sixth-Amendment safeguards; judges must craft procedures (e.g., using a CSO rather than an agent) that avoid party-juror contact.
Evidentiary clarity. The panel provides guidance on:
- Impeachment with FBI 302s—distinguishing questions about the statement (permitted) from introducing the document (permitted only if the witness adopted it).
- Business-records hearsay—recognising that third-party information may come in if the outsider was acting in a business capacity and the record shows sufficient trustworthiness.
Machinegun knowledge standard. Although not outcome-determinative here, the court reaffirmed that knowledge may be proven circumstantially through visible modifications, proximity to extended magazines, and possession of the firearm.

Complex Concepts Simplified

Colorable Claim of Juror Misconduct: A plausible allegation that, if true, could undermine juror impartiality. No smoking gun is required—just enough to warrant inquiry.
“Un-Flagging Duty” to Investigate: Once a colorable claim surfaces, the trial judge must make factual findings (e.g., juror voir dire, testimony from bailiffs). Doing nothing is an abuse of discretion.
Business-Records Exception (Rule 803(6)): Regularly kept records are admissible despite hearsay concerns because routine creation fosters reliability. If the record embeds another person’s statement, that statement is admissible only when the second declarant also acted in the ordinary course or under a business duty.
FBI Form 302: An agent’s summary of an interview. It is not the verbatim words of the witness unless the witness adopts or signs it. For impeachment, counsel may ask the witness about the prior statement; introducing the document itself requires foundation.
Knowledge Element of § 922(o): The government need not prove the defendant knew the law; only that he knew the gun was capable of automatic fire—e.g., through visible “switches,” extended magazines, prior handling.

Conclusion

United States v. Matta-Quiñones reinforces a core premise of American criminal justice: the jury’s deliberations must remain independent of all partisan influence. When there is any reasonable doubt that this independence was breached—even by a court-sanctioned safety procedure—the trial judge must investigate. The First Circuit’s decision sends an unequivocal message: silence or brevity of contact is irrelevant; what matters is the potential for prejudice and the court’s response. Practitioners should heed the court’s detailed guidance on preserving objections, handling exhibits, and safeguarding the sanctity of the jury room. Future cases, both in Puerto Rico and throughout the Circuit, will now proceed with a clearer blueprint for managing sensitive physical evidence without compromising constitutional guarantees.