Constructive Possession through “Tools-of-the-Trade” & the Nexus Test under § 924(c):
Commentary on United States v. Carlisa Allen, No. 24-4169 (4th Cir. Aug. 13 2025)

1. Introduction

In United States v. Carlisa Allen, the U.S. Court of Appeals for the Fourth Circuit affirmed the conviction and 336-month sentence of Ms. Carlisa Renea Allen for multiple federal drug-trafficking and firearm offenses stemming from a two-year narcotics conspiracy in the Research Triangle of North Carolina. The appellate decision is significant because it crystallises two doctrinal points:

1. Constructive Possession via “Tool-of-the-Trade” Containers: The court treated a camouflage bookbag and a Toyota RAV4, both repeatedly used in drug dealings, as “tools of the trade,” allowing a jury to infer Allen’s knowledge of—and intent to distribute—the drugs found inside, even though she never physically opened the bag in officers’ view.
2. Nexus Requirement under 18 U.S.C. § 924(c): The opinion highlights how proximity, ready accessibility, and contextual evidence (text messages, cash, baggies, scale) establish that a firearm was possessed “in furtherance of” a drug-trafficking crime, notwithstanding lawful ownership of the weapon.

Because digital evidence (text messages, phone notes), forensic toxicology, and eyewitness testimony were seamlessly knitted together, the Fourth Circuit’s discussion offers a contemporary template for future prosecutions involving fentanyl-laced narcotics, constructive possession, and the gun-drug interface.

2. Summary of the Judgment

• The panel (Niemeyer, J., joined by Diaz, C.J., and Berner, J.) affirmed all five counts of conviction.
• Applying the substantial-evidence standard, the court held that:
  • Allen constructively possessed cocaine and fentanyl with intent to distribute on March 15 2023.
  • She possessed a Glock .45 “in furtherance of” those offenses, satisfying § 924(c)(1)(A).
  • Fentanyl and cocaine sold by Allen’s co-conspirator were the “but-for” cause of student Joshua Zinner’s death, supporting the penalty enhancement under 21 U.S.C. § 841(b)(1)(C).
• The court emphasized its limited role on appeal: resolving only whether a rational trier of fact could find guilt beyond a reasonable doubt when evidence is viewed in the Government’s favor.

3. Detailed Analysis

3.1 Precedents Cited

1. United States v. Williams, 130 F.4th 177 (4th Cir. 2025) – Restates the substantial evidence benchmark and the appellate obligation to draw all inferences for the Government.
2. United States v. Roe, 606 F.3d 180 (4th Cir. 2010) – Quoted for principle that appellate courts assume jury resolved testimonial conflicts in the Government’s favor.
3. United States v. Moore, 769 F.3d 264 (4th Cir. 2014) & United States v. Lomax, 293 F.3d 701 (4th Cir. 2002) – Both outline factors evidencing a firearm’s advancement of drug dealing (accessibility, strategic location).
4. Muscarello v. United States, 524 U.S. 125 (1998) – Interprets § 924(c) broadly to cover guns mixed with drug trafficking.

These authorities collectively bolster the court’s refusal to disturb the jury’s findings. Notably, Williams is the court’s own recent en banc clarification of the sufficiency standard, making Allen the first published application to a fentanyl death-result case.

3.2 Legal Reasoning

a. Constructive Possession & Intent to Distribute

The panel analogised the bookbag and RAV4 to business instruments. Because text messages showed Allen regularly stored narcotics in the bag—often specifying pockets—the jury could infer:

• Knowledge – She knew what the bag contained on March 15.
• Dominion & Control – Frasier handed the bag to her; she placed it on the passenger seat; both routinely used her vehicle.
• Intent to Distribute – Quantity (7.34 g fentanyl, 80 oxycodone), tools (scale, baggies), and $12,000 cash far exceeded personal-use scenarios.

b. Firearm “In Furtherance” of Drug Trafficking

Following Moore/Lomax, the panel listed five nexus factors, all present here:

1. Proximity: Glock at Allen’s feet.
2. Accessibility: Loaded, extended magazine.
3. Strategic Location: Same vehicle habitually used for drug runs.
4. Contextual Evidence: Large cash, drug inventory, scale, baggies.
5. Prior Use: Texts showing Allen carried “purple” Glock for protection during deals.

The court rejected Allen’s claim of “general self-protection,” reiterating that lawful gun ownership does not negate § 924(c) liability when the firearm advances drug activity.

c. Causation of Death Enhancement

To sustain the § 841(b)(1)(C) enhancement, the jury had to find that fentanyl/cocaine were the but-for cause of Zinner’s death (Burrage v. United States, 571 U.S. 204 (2014) – implicitly guiding the analysis, though not cited). Evidence included:

• Lethal concentrations in toxicology.
• Empty baggies of Allen-Frasier “signature” (.5 g Ziplocs) near the body.
• Expert testimony deeming the drugs the “straw that broke the camel’s back.”

The panel held that cross-examination regarding Zinner’s Amoxicillin use went only to weight, not admissibility or sufficiency.

3.3 Impact on Future Litigation

1. Digital Breadcrumbs as Circumstantial Evidence – Courts will likely rely more heavily on text logs and cloud-stored notes to establish knowledge and intent.
2. Expansive View of “Tools-of-the-Trade” – Allen broadens the construct to encompass personal vehicles and containers when there is a demonstrated history of drug use.
3. Firearms & Fentanyl Era Enforcement – Prosecutors may invoke Allen to argue that any gun within reach of fentanyl is presumptively “in furtherance,” especially where lethal doses elevate penalties.
4. Appellate Deference after Williams – Allen illustrates that overcoming jury findings in the Fourth Circuit now faces an especially steep climb.

4. Complex Concepts Simplified

Constructive Possession

Legal fiction allowing a person to be treated as possessing contraband without physical custody if they have knowledge of it and the ability to exercise control.

Tool-of-the-Trade Doctrine

Recognises certain objects (cars, stash houses, containers) so commonly used in drug trafficking that their possession can suggest intent to distribute.

“In Furtherance” (18 U.S.C. § 924(c))

Requires a nexus between gun and drug crime—i.e., the firearm’s presence must advance or facilitate the offense, not merely coincide with it.

But-For Causation

A fact is a but-for cause if the result would not have occurred in its absence. In drug-death cases, the Government must show the victim would have lived had they not taken the charged drugs.

Substantial-Evidence Review

On appeal, verdicts stand if any rational juror could find guilt beyond a reasonable doubt when all evidence is viewed in the prosecution’s favor.

5. Conclusion

United States v. Carlisa Allen is less a doctrinal earthquake than a clarifying beacon in three crowded legal corridors: constructive possession, gun-drug nexus, and drug-induced deaths. By situating routine objects—a bookbag and an SUV—within the “tool-of-the-trade” framework, the Fourth Circuit makes it easier for prosecutors to prove intent without eyewitness testimony of the defendant opening a bag of contraband. Simultaneously, the panel underscores that lawful gun ownership cannot insulate defendants from § 924(c) where contextual clues reveal an unmistakable link between the firearm and narcotics commerce. Finally, the court’s acceptance of robust—but not exhaustive—medical evidence signals flexibility in proving but-for causation in fentanyl cases, a pressing concern amid the opioid crisis.

Going forward, investigators will likely foreground digital communications, recurring storage containers, and firearm placement to secure convictions, while defense counsel must focus on disrupting the “tool-of-the-trade” narrative and the nexus factors to create reasonable doubt. Ultimately, Allen fortifies prosecutorial pathways in the modern landscape of polysubstance trafficking and underscores the Fourth Circuit’s unwavering deference to jury verdicts under the substantial-evidence standard.