Circumstantial Knowledge Suffices: United States v. Rios-Alvarez and the First Circuit’s Clarification of Aiding-and-Abetting Liability in Federal Carjacking Cases

Introduction

United States v. Rios-Alvarez (1st Cir. July 25 2025) is a consolidated appeal arising from a violent Puerto Rico home-invasion that ultimately led to a federal carjacking charge. The three appellants – Anthony Rivera-Rivera, Victor M. Hernández-Carrasquillo, and Jimmy Ríos-Alvarez – were convicted of:

One count of armed carjacking, 18 U.S.C. §§ 2, 2119(2); and
One count of using a firearm during a crime of violence, 18 U.S.C. §§ 2, 924(c)(1)(A)(ii).

On appeal the defendants attacked (1) the sufficiency of the evidence – especially the “knowledge/intent” component of aiding-and-abetting carjacking, (2) delayed Brady disclosures, (3) denial of severance, (4) purported Confrontation Clause errors, and (5) sentencing determinations. The First Circuit affirmed in full.

The decision is noteworthy because it endorses a lower evidentiary threshold for proving an aider-and-abettor’s knowledge of a carjacking through circumstantial evidence alone, even when the defendant never enters the stolen vehicle. The Court also re-iterates standards regarding delayed disclosures, spill-over prejudice, Confrontation Clause limits, and the Guidelines’ abduction and serious-bodily-injury enhancements.

Summary of the Judgment

After reviewing all claims, Judge Montecalvo (joined by Judges Thompson and Aframe) held:

Sufficiency of Evidence: Reasonable jurors could find that each appellant aided and abetted a federal carjacking. The government need not present direct proof that an aider-and-abettor personally witnessed the taking of the car; circumstantial evidence that he remained with the victims, coordinated with the principals, and therefore could have walked away but chose not to suffices.
Delayed Brady Material: Although the government’s seven-year delay was inexcusable, the defendants failed to show actual prejudice or seek additional continuances. Dismissal was therefore unwarranted.
Severance: Denial of severance was proper because (a) defendants did not establish that codefendant Ríos would testify if trials were severed, and (b) any evidentiary spill-over was curable with limiting instructions.
Confrontation Clause: The challenged testimony involved non-testimonial hearsay (or no hearsay at all); thus Crawford did not bar it.
Sentencing: Application of the serious-bodily-injury and abduction enhancements, as well as criminal-history scoring, was upheld; the resulting sentences (180 & 235 months) were procedurally and substantively reasonable.

Analysis

1. Precedents Cited and Their Influence

Rosemond v. United States, 572 U.S. 65 (2014) – Sets out the two-prong test for aiding-and-abetting: an affirmative act plus intent (knowledge) at a time the accomplice can still quit. The panel uses Rosemond as the analytical backbone.
United States v. Rodríguez-Adorno, 695 F.3d 32 (1st Cir. 2012) – Provides guidance on carjacking intent (“conditional intent”) and reliance on violence used before or during the taking.
Holloway v. United States, 526 U.S. 1 (1999) – Defines the “intent to cause death or serious bodily harm” element in § 2119 as conditional.
United States v. Osorio, 929 F.2d 753 (1st Cir. 1991) – Source for the prejudice test when Brady material is disclosed late and the circumstances for exceptional dismissal.
Zafiro v. United States, 506 U.S. 534 (1993) – Governs severance requests; referenced to show limiting instructions can often cure prejudice.
Guideline cases (e.g., Whooten; Slow Bear) – Applied to uphold abduction and serious-bodily-injury enhancements.

2. The Court’s Legal Reasoning

a. Aiding-and-Abetting Carjacking – “Knowledge by Inference”

The Court distilled the following rule:

If the government presents circumstantial evidence allowing a rational juror to infer that the defendant (i) knew the car was being taken by force, (ii) could still opt out, yet (iii) continued to guard or restrain victims so the theft could succeed, the knowledge/intent element of aiding-and-abetting § 2119 is satisfied.

Key facts supporting knowledge for each defendant included: staying behind to guard victims, timing of departure only after ATM withdrawal succeeded, and participation in coordinated communication among assailants. Even where evidence referred broadly to they, the panel held that a sufficiently detailed mosaic permitted the jury’s inference, refusing to demand eyewitness testimony of each defendant learning of the car’s departure.

b. Conditional Intent under § 2119

Because the associates had already poured hot oil, kicked, stabbed, and brandished firearms, the principals’ willingness to inflict further harm to seize the Nissan was indisputable, satisfying Holloway.

c. Sentencing Enhancements and Foreseeability

Serious Bodily Injury (§ 2B3.1(b)(3)(B)) – Hospitalization, extreme pain, and a month-long rehabilitation regime met the guideline definition.
Abduction (§ 2B3.1(b)(4)(A)) – Forcing the bleeding victim from an upstairs living room to a vehicle at gunpoint constituted abduction to facilitate the offense; foreseeability extended the enhancement to co-defendants who remained upstairs.

d. Brady / Severance / Confrontation

The panel found no reversible error because defendants neither requested additional continuances nor showed any strategy truly foreclosed. On severance, the absence of an affidavit or firm representation that Ríos would testify proved fatal under the Drougas factors.

3. Impact of the Judgment

Evidentiary Sufficiency in Co-Conspirator Carjacking Cases: Prosecutors in the First Circuit can now rely more heavily on aggregate circumstantial proof to establish knowledge/intent against accomplices who are off-site when the vehicle is driven away.
Sentencing Guidance: The Court’s treatment of the abduction enhancement clarifies that even short-range intra-premise movements (e.g., from a second floor to a driveway) can qualify.
Brady Timing: While condemning the late production, the panel signals that defendants must press for continuances and articulate specific prejudice; mere lateness rarely secures dismissal.
Trial Management: Re-affirms trial judges’ broad discretion to deny severance absent concrete proof that co-defendants will waive Fifth Amendment rights.

Complex Concepts Simplified

Aiding & Abetting (18 U.S.C. § 2) – You can be guilty of a crime you did not personally carry out if you (i) intentionally help in some way and (ii) know the full plan while you are still free to withdraw.
Conditional Intent (Carjacking Statute § 2119) – The government need not show the car-taker wanted to kill; only that he would have seriously harmed or killed if that became necessary.
Serious Bodily Injury (Guidelines) – Injuries involving extreme pain, surgery, hospitalization, or significant rehabilitation.
Abduction Enhancement – Any forcible movement of a victim to a different location (even within the same property) to advance the offense can add four offense levels.
Brady Material – Evidence favorable to the defense that the prosecution must disclose in time for its effective use.
Plain-Error Review – An appellate safety-valve used when no proper objection was made below; the error must be clear, affect substantial rights, and threaten the integrity of proceedings.

Conclusion

United States v. Rios-Alvarez crystallizes an important evidentiary principle: a jury may infer an accomplice’s knowledge of a carjacking from coordinated conduct and timing, even without direct proof that the accomplice saw or discussed the theft of the vehicle. This lowers the government’s burden in multi-actor violent crimes where roles are fluid and testimony may be nonspecific. The decision also serves as a cautionary tale on delayed disclosures – condemning them yet insisting on concrete prejudice – and reinforces the breadth of the Guidelines’ abduction and serious-bodily-injury enhancements. Practitioners should note the Court’s insistence on timely continuance motions, explicit severance proffers, and precise Confrontation Clause objections. Moving forward, Rios-Alvarez will likely be cited whenever defendants argue that mere “presence” and circumstantial participation are insufficient to prove aiding-and-abetting a federal carjacking.