Rule 12 Waiver for Newly Reframed Suppression Theories and Continued Foreclosure of § 922(g)(1) Challenges After Vincent II

1. Introduction

Parties and posture. The United States prosecuted James Nemeth for (1) possessing methamphetamine with intent to distribute and (2) being a felon in possession of a firearm. The charges stemmed from a search of Nemeth’s motel room (Room 140 at a Super 8 in Evansville, Wyoming) after a trained narcotics dog (“Duke”) performed a sniff in the motel hallway and alerted at Nemeth’s door. Nemeth entered a conditional guilty plea (preserving the suppression issue) and appealed the denial of (i) his motion to suppress and (ii) his motion to dismiss the felon-in-possession counts.

Key issues on appeal.

• Fourth Amendment (suppression): Whether Nemeth could argue on appeal that the dog sniff violated a reasonable expectation of privacy inside his motel room under Katz v. United States, 389 U.S. 347 (1967), when his district-court framing focused on privacy in the hallway outside the room.
• Second Amendment (dismissal): Whether 18 U.S.C. § 922(g)(1) is unconstitutional under New York State Rifle & Pistol Ass'n, Inc. v. Bruen, 597 U.S. 1 (2022), particularly after United States v. Rahimi, 602 U.S. 680 (2024).

2. Summary of the Opinion

The Tenth Circuit affirmed. It declined to reach the merits of Nemeth’s Fourth Amendment claim because it deemed his appellate theory (privacy inside the motel room) materially different from what he presented below (privacy in the hallway), rendering the appellate argument waived under Federal Rule of Criminal Procedure 12 absent a showing of good cause—none was offered.

The court also rejected the Second Amendment challenge because it remained foreclosed by circuit precedent, specifically Vincent v. Bondi, 127 F.4th 1263 (10th Cir. 2025) (Vincent II), which readopted Vincent v. Garland, 80 F.4th 1197 (10th Cir. 2023) (Vincent I) and reaffirmed the continuing binding effect of United States v. McCane, 573 F.3d 1037 (10th Cir. 2009).

3. Analysis

3.1 Precedents Cited

A. Preservation and waiver in suppression litigation (Rule 12)

The court’s dispositive Fourth Amendment holding is procedural, anchored in Rule 12 and a line of Tenth Circuit cases insisting that suppression theories be articulated with specificity in the district court.

• Fed. R. Crim. P. 12(b)(3)(C) and 12(c)(3): Suppression motions must be filed pretrial when the basis is reasonably available; untimely arguments are barred absent good cause.
• United States v. Warwick, 928 F.3d 939 (10th Cir. 2019): The court invoked Warwick for the proposition that appellate courts must decline review of suppression arguments not made in a motion to suppress, absent good cause.
• United States v. Herrera, 51 F.4th 1226 (10th Cir. 2022): Cited to treat a “new [suppression] argument on appeal” as untimely under Rule 12.
• United States v. Burke, 633 F.3d 984 (10th Cir. 2011): Central authority: Rule 12(c)(3) good-cause—not Rule 52(b) plain error—governs newly raised suppression theories; absent good cause, the issue is waived (barred).
• United States v. Bowline, 917 F.3d 1227 (10th Cir. 2019) and United States v. Lowe, 117 F.4th 1253 (10th Cir. 2024): Confirmed Burke’s approach remains valid after amendments to Rule 12.

What is “new” here? Not the general idea that suppression arguments can be waived, but the court’s insistence that a shift in the location of the asserted reasonable expectation of privacy—“hallway” below versus “inside the room” on appeal—is a sufficiently different legal theory to trigger Rule 12 waiver. The panel underscored that the “precise place of the alleged search” can control the Fourth Amendment analysis, making that shift consequential rather than semantic.

B. Fourth Amendment “reasonable expectation of privacy” framework

Although the panel did not reach the merits, it surveyed (and framed) the substantive landscape, highlighting why the merits question is unsettled.

• Katz v. United States, 389 U.S. 347 (1967): Foundational “reasonable expectation of privacy” test (via Justice Harlan’s concurrence).
• Carpenter v. United States, 585 U.S. 296 (2018) (quoting Smith v. Maryland, 442 U.S. 735 (1979)): Reinforced the “seeks to preserve as private” and “society recognizes as reasonable” formulation.
• California v. Ciraolo, 476 U.S. 207 (1986) and United States v. Nicholson, 144 F.3d 632 (10th Cir. 1998): Reiterated that Fourth Amendment searches are keyed to legitimate expectations of privacy.
• Minnesota v. Carter, 525 U.S. 83 (1998) and United States v. Gordon, 168 F.3d 1222 (10th Cir. 1999): Emphasized that the extent of Fourth Amendment protection depends on “where” and the defendant’s connection to the place.
• United States v. Wells, 739 F.3d 511 (10th Cir. 2014): Cited for the idea that connection to place is a factor in the privacy analysis.
• Stoner v. California, 376 U.S. 483 (1964): Used by the district court (and noted by the panel) to recognize privacy in the motel room itself, even if not necessarily in adjacent common areas.

C. Dog-sniff doctrine and the “dwelling-door” question (survey only)

The panel cataloged Supreme Court and circuit decisions bearing on whether a drug dog’s sniff at a dwelling door can be a Fourth Amendment “search.” It concluded the issue is open in the Supreme Court and the Tenth Circuit and split among other circuits—one reason it declined to excuse waiver.

• Kyllo v. United States, 533 U.S. 27 (2001): Sense-enhancing technology not in general public use to obtain information regarding the interior of the home can constitute a search. Nemeth relied on Kyllo on appeal to analogize a dog sniff to “sense-enhancing” detection.
• Illinois v. Caballes, 543 U.S. 405 (2005), United States v. Place, 462 U.S. 696 (1983), and United States v. Jacobsen, 466 U.S. 109 (1984): Dog sniffs (and contraband-only tests) are often treated as non-searches because they reveal only contraband, in which there is no legitimate privacy interest.
• Florida v. Jardines, 569 U.S. 1 (2013): Held a dog sniff on the front porch was a search on a property-based theory (curtilage intrusion), while not deciding the Katz question; Justice Kagan’s concurrence suggested Kyllo-like reasoning might apply in the home context.
• United States v. Whitaker, 820 F.3d 849 (7th Cir. 2016): Treated a dog sniff at an apartment door as a search under a privacy-based analysis.
• United States v. Lewis, 38 F.4th 527 (7th Cir. 2022): Distinguished hotel rooms from apartment homes and held no legitimate expectation of privacy “to be free of dog sniffs” in an exterior hotel hallway.
• United States v. Thomas, 757 F.2d 1359 (2d Cir. 1985): Held a dog sniff outside an apartment door was a search because of heightened dwelling privacy.
• United States v. Scott, 610 F.3d 1009 (8th Cir. 2010) and United States v. Johnson, 148 F.4th 287 (4th Cir. 2025): Adopted a more categorical reading of Caballes/Place: a dog sniff that reveals only contraband is not a search, even at a dwelling door.

D. Second Amendment challenges to § 922(g)(1) after Bruen and Rahimi

• New York State Rifle & Pistol Ass'n, Inc. v. Bruen, 597 U.S. 1 (2022): Established the “historical tradition” test for Second Amendment questions.
• United States v. Rahimi, 602 U.S. 680 (2024): Further developed Bruen-style methodology; Nemeth argued it undermined prior Tenth Circuit decisions.
• Vincent v. Garland, 80 F.4th 1197 (10th Cir. 2023) (Vincent I), United States v. McCane, 573 F.3d 1037 (10th Cir. 2009), and Vincent v. Bondi, 127 F.4th 1263 (10th Cir. 2025) (Vincent II): The panel treated Vincent II as controlling, expressly noting that McCane remains binding after Rahimi and that Vincent I was readopted.

3.2 Legal Reasoning

A. The suppression appeal failed on Rule 12 preservation

The court drew a sharp line between two theories: (1) the one it understood Nemeth to have advanced below—an expectation of privacy in the motel hallway outside the door—and (2) the one Nemeth pressed on appeal—an expectation of privacy inside the motel room, invaded by a dog sniff conducted from outside. Because the district court resolved only the first (and did not “pass upon” the second), the appellate argument was treated as a new suppression theory, untimely under Rule 12(c)(3), and waived absent good cause.

The court also declined to overlook the waiver under discretionary doctrines (including “waiver of the waiver”), emphasizing that it will do so only in “the most unusual circumstances” and that the merits question—dog sniffs at dwelling doors under Katz—is unsettled and circuit-splitting, making the “proper legal disposition” not “beyond reasonable doubt.”

B. The Second Amendment challenge failed on binding circuit precedent

Nemeth’s argument that the Supreme Court’s handling of Vincent I and the issuance of Rahimi demanded a different result was answered by intervening circuit authority. The panel relied on Vincent II as having already resolved the precise question, reaffirming that McCane remains binding. Accordingly, the district court’s denial of the motion to dismiss was affirmed.

C. The concurrence highlights a live intra-case dispute: what counts as “the same” argument?

Judge Moritz agreed on the Second Amendment issue but would have reached—and rejected—the Fourth Amendment claim on the merits. The concurrence viewed the majority as “pars[ing] the arguments too closely,” reasoning that Nemeth’s district-court briefing already asserted that the dog sniff gathered information about what was occurring inside a protected space. On the merits, the concurrence would have applied Caballes/Place in a largely categorical way: because the dog sniff reveals only contraband and Nemeth disavowed any property-based intrusion theory, no “search” occurred.

Practically, the split between the majority and concurrence flags two competing appellate instincts: (i) procedural rigor in defining whether a theory was fairly presented to the trial judge, versus (ii) pragmatic recognition that Fourth Amendment “place” arguments often blend and that litigation should resolve the constitutional question when it has been teed up.

3.3 Impact

A. Suppression practice: the opinion’s most immediate operational effect

Even as a nonprecedential disposition, Nemeth is a pointed warning about suppression motion drafting:

• Frame the “invaded place” explicitly. A Katz theory must identify whether the defendant’s asserted privacy interest is in the interior (home/room), the threshold/door area, or a common area (hallway). The court treated a shift in that “place” as a different argument for Rule 12 purposes.
• Do not rely on citations alone to preserve a theory. The panel acknowledged Whitaker was cited below, but held Nemeth did not clearly connect it to an “inside-the-room” privacy claim.
• Good cause matters—and must be argued. Once a court characterizes an appellate suppression contention as new, Rule 12(c)(3) requires an affirmative showing of good cause; silence is fatal.

B. Substantive Fourth Amendment law: an open question remains open

The panel expressly avoided resolving whether “a drug dog sniff at the door of a dwelling (here, a motel room) violates the occupant’s reasonable expectation of privacy inside the dwelling,” and emphasized it did not intend to foreclose future litigants from raising the issue. The opinion’s survey nonetheless maps the doctrinal battlefield: Caballes/Place’s “contraband-only” logic versus Kyllo/Jardines’ home-centric privacy concerns, plus an emerging split among circuits.

C. Second Amendment: continued stability (in the Tenth Circuit) for § 922(g)(1)

The decision reinforces that, in the Tenth Circuit, facial and as-applied challenges to § 922(g)(1) remain foreclosed by Vincent II and McCane, notwithstanding Bruen and Rahimi, absent intervening Supreme Court authority or en banc change.

4. Complex Concepts Simplified

• “Reasonable expectation of privacy” (Katz): A two-part idea: (1) you actually expected privacy, and (2) society is willing to recognize that expectation as reasonable—often turning on location (home versus public).
• “Free-air sniff”: Deployment of a trained dog to smell for contraband in the air around an area (here, a car and then motel doors).
• Dog sniff as “search”: Under Caballes/Place/Jacobsen, many courts treat dog sniffs as not being searches because they reveal only contraband. But when the sniff targets a dwelling door, some courts (e.g., Whitaker, Thomas) treat it as a search because the home has heightened privacy protection.
• Property-based vs privacy-based Fourth Amendment theories: A search can occur either by (i) physically intruding on protected property (curtilage/home), or (ii) invading a reasonable expectation of privacy. Nemeth abandoned the property-based approach on appeal.
• Waiver under Rule 12 (suppression): If you do not raise a suppression argument in the district court (or raise a materially different one), appellate courts generally will not consider it—unless you show “good cause.”
• “Waiver of the waiver”: An appellee can forfeit the ability to argue the appellant waived an issue by failing to raise waiver. But the court has discretion to enforce waiver anyway, especially where resolving the new issue would be uncertain or fact-sensitive.

5. Conclusion

United States v. Nemeth affirms convictions while delivering a pointed procedural lesson: in suppression litigation governed by Federal Rule of Criminal Procedure 12, appellate courts in the Tenth Circuit may treat a change in the identified locus of privacy—from a common hallway to the interior of a dwelling—as a new and waived theory unless the defendant shows good cause. Substantively, the decision leaves unresolved (but carefully surveyed) the nationally disputed question whether a drug dog sniff at a dwelling door is a Katz “search.” Finally, the court reiterates that Second Amendment challenges to § 922(g)(1) remain foreclosed in this circuit by Vincent v. Bondi, 127 F.4th 1263 (10th Cir. 2025) (Vincent II) and United States v. McCane, 573 F.3d 1037 (10th Cir. 2009).