Karen Lowy v. Daniel Defense, LLC

Circuit 4Feb 11, 2026

Split Score

SplitScore: 54/100

Case Summary

Disposition

Reversed in Part

The Fourth Circuit held that the plaintiffs—victims of a 2022 D.C. school shooting—adequately alleged Article III standing to sue numerous firearms and accessories manufacturers for deceptive marketing and negligence. It therefore reversed the district court’s dismissal for lack of standing, vacated the district court’s alternative PLCAA merits rulings as advisory, and remanded for further proceedings.

View Full Opinion Document (PDF)

Circuit Split Identified

Legal Issue

What level of causation is required to satisfy Article III's traceability element when a plaintiff's injury is inflicted by an independent third party—must the defendant's conduct have a 'determinative or coercive effect' on the third party, or is a 'predictable effect' sufficient?

Circuit Positions

Circuit 4(this circuit)

Plaintiff must allege the defendant’s conduct had a determinative or coercive effect on the third party to satisfy Article III traceability.

Circuit 2

A predictable effect on the third party’s actions satisfies Article III traceability; no determinative or coercive showing is required.

Conflict Summary

The Fourth Circuit has traditionally required plaintiffs to show the defendant’s actions had a ‘determinative or coercive effect’ on the third party (per Bennett v. Spear and Fourth-Circuit precedent such as Sheppheard v. Morrisey). The Second Circuit, however, recently held that standard ‘overstates the showing that is required,’ concluding that injury is fairly traceable so long as the defendant’s conduct had a ‘predictable effect’ on the third party’s actions (Ateres Bais Yaakov v. Clarkstown).

Parties & Counsel

Parties

Appellant:Karen Lowy and Antonio Harris
Appellee:Daniel Defense, LLC, et al.

Legal Counsel

Appellant:Elizabeth C. Lockwood, ALI & LOCKWOOD LLP (lead), with Kathryn M. Ali and Meghan Palmer
Appellee:Brian W. Barnes, COOPER & KIRK, PLLC (lead), plus multiple firm counsel for individual defendants