Government Forfeiture of Appeal-Waiver by Silence: Clarifying Jurisdiction and Forfeiture in United States v. Riojas

Introduction

United States v. Riojas, decided June 4, 2025 by the Fifth Circuit, addresses two interrelated issues:

Whether an unconditional guilty plea—ordinarily a waiver of all non-jurisdictional appellate challenges—must be invoked by the government or can be raised sua sponte by the court.
Whether the warrantless search of Mr. Riojas’s vehicle, following a traffic stop, satisfied the Fourth Amendment’s requirements under the automobile exception.

The case arises from a late-night traffic stop in Corpus Christi, Texas, during which officers detected the odor of marijuana, observed paraphernalia, and seized controlled substances. Isaac Riojas pleaded guilty unconditionally to drug and firearms charges, but later sought to challenge the constitutionality of the search on appeal. The government did not invoke the plea-waiver, raising a novel question for this Court: must the waiver be raised by the government or may the appellate court do so on its own motion?

Summary of the Judgment

The Fifth Circuit unanimously held:

An unconditional guilty plea ordinarily waives all non-jurisdictional defects, including pre-plea suppression rulings.
The government never invoked that waiver on appeal and has therefore forfeited the benefit of the plea-waiver bar.
Appeal waivers are non-jurisdictional claim-processing rules and do not deprive the court of subject-matter jurisdiction.
Reaching the merits, the Court affirmed the district court’s denial of Riojas’s suppression motion under the automobile exception to the Fourth Amendment.

Analysis

1. Precedents Cited

Tollett v. Henderson, 411 U.S. 258 (1973): Established that an unconditional guilty plea “breaks the chain of events” and generally bars independent review of pre-plea constitutional claims.
United States v. Coil, 442 F.3d 912 (5th Cir. 2006): Confirmed that an unconditional plea waives all non-jurisdictional defects, including suppression rulings.
Jacobo Castillo (9th Cir. en banc), 496 F.3d 947 (2007): Held that a guilty plea does not deprive the court of jurisdiction; waivers are claim-processing rules that the government must invoke.
United States v. Combs (7th Cir.), 657 F.3d 565 (2011): Treated the plea waiver as jurisdictional and enforced it sua sponte, creating a direct circuit split with Castillo and the Tenth Circuit’s decisions.
United States v. De Vaughn (10th Cir.), 694 F.3d 1141 (2012): Adopted the Ninth Circuit’s approach, emphasizing limited exceptions to the Tollett bar but declining to treat the waiver as jurisdictional.
Jurisdictional principles from 28 U.S.C. § 1291, Steel Co. v. Citizens for Better Environment, 523 U.S. 83 (1998), and ancillary precedents confirm that subject-matter jurisdiction cannot be conferred or ousted by party agreement.

2. Legal Reasoning

The Court’s reasoning proceeds in two steps:

Jurisdiction and Waiver-Forfeiture:
- Appeal waivers embedded in unconditional guilty pleas are non-jurisdictional claim-processing rules, not jurisdictional bars.
- Subject-matter jurisdiction under 28 U.S.C. § 1291 remains intact despite contractual waiver of appellate rights.
- The government’s silence on appeal amounts to forfeiture of its own right to invoke the waiver—it did not “intentionally relinquish” (waiver), but it failed to “timely assert” (forfeiture) the plea-waiver.
- Absent government invocation, the Court may—and here must—address the merits of suppression claims.
Fourth Amendment Merits:
- The district court correctly applied the automobile exception to the Fourth Amendment warrant requirement.
- Probable cause existed based on:
  - The smell of actively burning marijuana upon opening the vehicle door;
  - Officer Perez’s extensive experience with drug interdiction and recognition of paraphernalia;
  - Physical evidence (ashes on the defendant’s lap, a “roach” on the floorboard) and the defendant’s furtive movements;
  - The vehicle’s ready mobility.
- Because probable cause justified the warrantless search under the automobile exception, suppression was properly denied regardless of any plain-view analysis missteps.

3. Impact

This decision clarifies and cements several important legal principles:

Non-invocation ≠ Bar: An appellate waiver must be invoked by the government or is forfeited; the appellate court will not raise it sua sponte.
Jurisdiction Remains Unaffected: Contractual waivers of appeal rights do not oust federal courts of subject-matter jurisdiction; § 1291 governs finality and appealability.
Encouragement of Clear Preservation: Parties must explicitly invoke plea waivers in briefs to preclude merits review—a procedural obligation underscored by Riojas.
Reinforcement of Automobile Exception: Affirms that an officer’s reliable sensory observations—especially the odor of contraband—can furnish probable cause for a vehicle search.
Uniformity Across Circuits: The Fifth Circuit’s stance aligns with the Ninth and Tenth Circuits, narrowing the existing circuit split and providing guidance for future appeals.

Complex Concepts Simplified

Unconditional Guilty Plea: A plea in which the defendant admits guilt without retaining the right to appeal non-jurisdictional issues (e.g., Fourth Amendment claims). Such pleas normally bar those issues on appeal.
Plea-Waiver vs. Forfeiture:
- Waiver = intentional relinquishment of a known right.
- Forfeiture = failure to timely assert a right, allowing the court to decline application of the rule.
Automobile Exception: Under the Fourth Amendment, officers may search a vehicle without a warrant if they have probable cause to believe it contains contraband or evidence of crime, given the vehicle’s inherent mobility.
Subject-Matter Jurisdiction: The court’s legal authority to hear a case, derived from statute (e.g., 28 U.S.C. § 1291). It cannot be created or destroyed by parties’ agreements.

Conclusion

United States v. Riojas solidifies the principle that an unconditional guilty plea’s appeal-waiver is a claim-processing rule—non-jurisdictional and forfeitable if not invoked by the government. The Fifth Circuit thus retains jurisdiction, addresses the suppression issue on the merits, and confirms that the automobile exception justified the search. This ruling guides criminal practitioners to invoke or preserve plea-waivers affirmatively and underscores the interplay between appellate procedure and Fourth Amendment jurisprudence.