Coordinated Firearm Sales Create Jointly Undertaken Relevant Conduct for U.S.S.G. § 2K2.1 Enhancements

I. Introduction

In United States v. Jackson (10th Cir. June 16, 2026), Darrius Deangelo Jackson appealed the sentence imposed after his guilty plea to being a felon in possession of a firearm, in violation of 18 U.S.C. § 922(g)(1). The sentencing dispute turned on whether Jackson’s “relevant conduct” under U.S.S.G. § 1B1.3 included firearms sold and possessed by his cohorts during coordinated firearm transactions with undercover ATF agents.

The key issues were whether the district court properly applied (1) the higher base offense level under U.S.S.G. § 2K2.1(a)(1) (triggered, as applied here, by offense involvement with a qualifying firearm such as one with a large-capacity magazine or a firearm described in 26 U.S.C. § 5845(a)), and (2) the firearm-count enhancement under U.S.S.G. § 2K2.1(b)(1)(A) (three or more firearms), based on firearms handled by others.

Although designated as an “Order and Judgment” and expressly nonprecedential (except for law-of-the-case, res judicata, and collateral estoppel), the decision provides a clear, practical application of jointly undertaken criminal activity principles to firearms guideline enhancements.

II. Summary of the Opinion

The Tenth Circuit affirmed. It held that Jackson’s relevant conduct encompassed a cohort’s August 13 firearm sale (an AM-15 pistol equipped with a large-capacity magazine) because Jackson and the cohort traveled together to sell firearms and acted in a coordinated manner that provided mutual assistance and protection. That firearm:

  • Supported the § 2K2.1(a)(1) base offense level because it was a semiautomatic firearm with a large-capacity magazine; and
  • Provided the “third firearm” necessary for the § 2K2.1(b)(1)(A) enhancement (three or more firearms).

The court rejected Jackson’s arguments that the district court (a) relied merely on presence over two days and (b) failed to make particularized findings as to the scope of jointly undertaken activity. The panel concluded the district court sufficiently identified an implicit agreement fairly inferred from coordinated conduct and properly found the cohort’s acts were in furtherance of, and reasonably foreseeable in connection with, the jointly undertaken activity.

III. Analysis

A. Precedents Cited

1. Review standards framing the appeal

  • United States v. Cifuentes-Lopez, 40 F.4th 1215, 1218 (10th Cir. 2022): supplied the general appellate framework— legal guideline conclusions reviewed de novo, fact findings for clear error, and deference to guideline application. This enabled the panel to separate the “what happened” questions from the “what the Guidelines require” questions.
  • United States v. Jackson, 138 F.4th 1244, 1256 (10th Cir. 2025): emphasized that the “ultimate determination of relevant conduct is reviewed de novo.” That is critical here because the main dispute was attribution under § 1B1.3.
  • United States v. Munoz, 812 F.3d 809, 817 (10th Cir. 2016): underscored that reliance on clearly erroneous facts is an abuse of discretion. Jackson attempted to recharacterize the record as mere “presence,” but the panel found the district court’s factual inferences permissible.

2. Jointly undertaken activity and mutual protection

  • United States v. Ellis, 23 F.4th 1228, 1251 (10th Cir. 2022): the key Tenth Circuit analogue. In Ellis, coordinated travel and plausible mutual assistance/protection supported a finding of jointly undertaken criminal activity even when the defendants’ direct transactions were separate. The panel used Ellis to rebut Jackson’s attempt to treat each seller as an isolated “standalone” actor.
  • United States v. Damon, 595 F.3d 395, 402 (1st Cir. 2010): persuasive authority illustrating that when participants coordinate to achieve an unlawful acquisition objective “at the same time” and “through the same proxy,” each can be responsible for all firearms under § 1B1.3(a)(1)(B). The Tenth Circuit invoked this to show that firearms accountability can be collective when the criminal activity is collective.
  • United States v. Rollins, 861 F. App’x 257, 260 (10th Cir. 2021): another example of attribution in a felon-in-possession setting, where a defendant driver was treated as engaged in jointly undertaken criminal activity when the passenger fired a gun. The citation signals that “felon-in-possession” does not categorically cabin relevant conduct to a single defendant’s hands.

3. Guidelines commentary example adopted as an analogy

The court relied heavily on the Sentencing Commission’s own illustration in U.S.S.G. § 1B1.3 n.4(C)(viii) (the “drug backpackers” example). The example distinguishes coordinated, mutually protective joint conduct (aggregate accountability) from independent operations (individual accountability). The court treated Jackson’s conduct as the coordinated version of that example.

B. Legal Reasoning

1. The court’s narrowing move: focusing on August 13

The panel affirmed without needing to resolve the more complex question of whether a cohort’s August 12 machinegun-conversion device firearm could be drawn into Jackson’s “expanded” relevant conduct under § 1B1.3(a)(2). Instead, it found the August 13 cohort sale sufficient because it occurred “during” the offense timeframe and directly supported the contested enhancements.

2. The operative attribution rule: § 1B1.3(a)(1)(B)

The enhancements rose or fell on whether the cohort’s August 13 firearm was part of Jackson’s relevant conduct as an act of another person within “jointly undertaken criminal activity,” meaning:

  • a “criminal plan, scheme, endeavor, or enterprise” undertaken in concert (even if not charged as a conspiracy);
  • within the scope of the jointly undertaken activity;
  • in furtherance of that activity; and
  • reasonably foreseeable in connection with that activity.

3. “Implicit agreement” inferred from coordinated conduct

Jackson argued the district court improperly “assumed” an implicit agreement based on mere presence. The panel rejected that characterization, emphasizing the district court’s supported inference from coordination: Jackson and Beach arrived together at the 7-Eleven to sell firearms, facilitated each other’s dealings, and functioned with mutual awareness and protection while armed sales occurred. That evidence, the panel held, supports an implicit agreement “fairly inferred” from conduct—precisely the method endorsed by § 1B1.3 n.3(B).

4. “Particularized findings” on scope were sufficiently made

Jackson also contended the district court failed to make specific scope findings. The panel pointed to the sentencing transcript where the district court:

  • explicitly addressed the “scope” requirement;
  • invoked the explicit/implicit agreement framework from the commentary; and
  • found that coordinated travel, presence during transactions, and mutual awareness fairly inferred a scope encompassing the transportation, possession, and sale of multiple firearms during the joint outings.

These findings mattered because the Guidelines do not impose vicarious liability for everything an associate does; they impose liability for what falls within the scope of the jointly undertaken activity. The panel concluded that the district court meaningfully identified that scope rather than applying a blanket “guilt by association” rule.

5. Furtherance and foreseeability were straightforward on these facts

Finally, the panel treated “furtherance” and “reasonable foreseeability” as obvious. This was not a case where an unplanned act (e.g., a sudden, unrelated shooting) occurred during a criminal episode. The entire objective was the illegal sale of firearms, and the cohort’s gun possession and sale directly advanced that objective.

C. Impact

Practically, the decision reinforces several points likely to influence future sentencing disputes (even if only as persuasive authority):

  • Firearms guideline exposure can expand quickly through § 1B1.3: A defendant convicted of possessing a single gun can face enhancements triggered by other guns present in the jointly undertaken venture (e.g., large-capacity magazine firearms, NFA-described firearms, or firearm counts).
  • Coordination evidence is pivotal: Courts may infer “implicit agreement” from coordinated travel, synchronized transactions, mutual awareness, and protective posture—facts that often appear in undercover buy operations.
  • Scope findings remain a litigation checkpoint: The opinion signals that defendants can still contest whether the district court identified the scope with sufficient specificity, but also shows what will usually satisfy that requirement: tying scope to concrete coordination behaviors and the objective of the outing.
  • Offense-of-conviction date framing matters: By affirming on the August 13 transaction, the panel illustrates an appellate path: uphold enhancements based on conduct “during” the offense, avoiding harder “same course of conduct/common scheme” disputes under § 1B1.3(a)(2) when unnecessary.

IV. Complex Concepts Simplified

  • Relevant conduct: Not just what the defendant was convicted of, but additional acts the Guidelines treat as part of sentencing—sometimes including acts of others.
  • Jointly undertaken criminal activity: A shared criminal plan carried out together. It can exist without a charged conspiracy.
  • Implicit agreement: An agreement inferred from coordinated actions (showing teamwork), not necessarily from explicit words.
  • Scope (for § 1B1.3(a)(1)(B)): The boundaries of what the defendant agreed to jointly do. A defendant is not automatically responsible for all wrongdoing by associates—only what falls within the jointly undertaken plan’s scope.
  • In furtherance / reasonably foreseeable: The other person’s act must advance the shared plan and be the kind of act one would expect given that plan.
  • § 2K2.1(a)(1) and § 2K2.1(b)(1)(A): Guideline provisions that can increase a firearm offender’s advisory range based on the type of firearm involved (e.g., large-capacity magazine) and the number of firearms involved.

V. Conclusion

United States v. Jackson affirms that, for firearms sentencing, jointly undertaken criminal activity can make a defendant accountable for cohort firearms when coordination and mutual protection demonstrate an implicit agreement and the acts fall within the scope, furtherance, and foreseeability limits of U.S.S.G. § 1B1.3(a)(1)(B). The opinion’s core takeaway is doctrinally modest but practically significant: in coordinated gun-sale outings, defendants risk enhancements driven by the group’s firearms, not merely the one named in the indictment.