Enforcing Appeal Waivers to Bar Review of Plea-Withdrawal Denials and Applying Leon Good-Faith Where Warrants Show a “Modicum of Evidence” of Nexus

I. Introduction

Case: United States v. Claibon Burrus (Sixth Circuit, Mar. 12, 2026) (unpublished).
Parties: United States of America (Plaintiff-Appellee) v. Claibon Burrus (Defendant-Appellant).
Background: Memphis police investigated a fatal overdose involving J.O. A confidential informant and family members connected J.O.’s drug purchases to a dealer known as “Yai/Yay,” associated with a phone number ending in 7846 and a residence at 3038 Brookdale in Memphis. Officers obtained warrants for (1) phone records/GPS data tied to the number, (2) a search of the Brookdale residence, and (3) searches of three storage units linked to a key found in the residence and later corroborated by storage-employee identification and a K9 sniff.

Procedural posture and key issues on appeal:

  • Plea withdrawal/vacatur: After pleading guilty under a written plea agreement containing an appeal waiver, Burrus moved to vacate his plea, claiming his strained attorney relationship affected his understanding. The district court denied the motion. On appeal, Burrus sought review of that denial.
  • Suppression motions: Burrus appealed the denial of motions to suppress evidence from the phone-records warrant, the residence warrant, and the storage-unit warrants—arguing primarily lack of probable cause/nexus, informant unreliability, staleness, and K9 unreliability (a “false alert” on an ultimately empty unit).

II. Summary of the Opinion

The Sixth Circuit affirmed in full. It held that Burrus’s challenge to the denial of his motion to vacate his guilty plea was barred by the appeal waiver in his plea agreement because (a) the claim fell within the waiver’s scope and (b) Burrus entered the waiver knowingly and voluntarily.

As to suppression, the court relied on the good-faith exception under United States v. Leon, concluding that—even assuming arguendo some deficiency in probable cause—the affidavits were not “bare bones” and provided at least a minimally sufficient nexus (a “modicum of evidence”) between alleged drug activity and the targeted phone records, residence, and storage units. Therefore, suppression was inappropriate.

III. Analysis

A. Precedents Cited

1. Appeal waivers and their enforcement

  • United States v. Mendez-Santana, 645 F.3d 822 (6th Cir. 2011)
    Used for the threshold proposition that a defendant must show he has preserved the right to appeal the issue presented. In Burrus’s case, the appeal waiver foreclosed review of the plea-vacatur denial.
  • United States v. Detloff, 794 F.3d 588 (6th Cir. 2015)
    Provides the standard of review: whether a defendant waived appellate rights in a plea agreement is reviewed de novo. The panel applied this framework to interpret the waiver’s scope and validity.
  • United States v. Ellis, 115 F.4th 497 (6th Cir. 2024)
    Central authority for two points: (i) appeal waivers are “routinely” enforced when entered knowingly and voluntarily; (ii) the plea colloquy creates a “formidable barrier” to later claims of misunderstanding. The court used Ellis to emphasize the primacy of the plea agreement’s text and the plea-hearing record.
  • Garza v. Idaho, 586 U.S. 232 (2019)
    Cited to situate appeal waivers within broader doctrine: waivers can validly limit appellate review even while certain rights/claims may remain in other contexts. Here, it supported the general legitimacy of waivers.
  • United States v. Milliron, 984 F.3d 1188 (6th Cir. 2021)
    Supplies the two-part test applied by the panel: an appeal waiver is enforced if (1) the claim is within its scope and (2) the defendant knowingly and voluntarily agreed.
  • United States v. Beals, 698 F.3d 248 (6th Cir. 2012)
    Quoted via Ellis for the contract-like principle that courts enforce waivers “according to [their] terms” to give effect to party intent as reflected in the plain language.

2. Suppression standards, probable cause, and good-faith reliance

  • United States v. McPhearson, 469 F.3d 518 (6th Cir. 2006) and United States v. Williams, 962 F.3d 1218 (6th Cir. 1992)
    Provide appellate review standards for suppression rulings: factual findings for clear error, legal conclusions de novo, viewing evidence in the light most supportive of the district court’s decision.
  • United States v. Leon, 468 U.S. 897 (1984)
    The backbone of the court’s suppression analysis. The panel treated Leon as dispositive: if officers reasonably relied on a facially valid warrant, evidence generally is not excluded even if probable cause was arguably lacking.
  • United States v. Christian, 925 F.3d 305 (6th Cir. 2019) (en banc)
    Key to the “bare bones” analysis: defines when an affidavit is so deficient that good faith cannot apply—i.e., one stating suspicions or conclusions without underlying facts regarding veracity, reliability, and basis of knowledge. The court emphasized the “high burden” and the “woefully deficient” threshold.
  • United States v. White, 874 F.3d 490 (6th Cir. 2017)
    Used for operational standards: (i) suppression is appropriate only if a reasonably trained officer would have known the search illegal despite the warrant; (ii) examples of conclusory/bare-bones affidavits; and (iii) the “modicum of evidence” phrasing for nexus in good-faith analysis.
  • United States v. Washington, 380 F.3d 236 (6th Cir. 2004)
    Cited (through Christian) for the “bare bones” definition and the emphasis on needing underlying factual circumstances.
  • United States v. Carpenter, 360 F.3d 591 (6th Cir. 2004) and United States v. Laughton, 409 F.3d 744 (6th Cir. 2005)
    Provide the “minimally sufficient nexus” and “some modicum of evidence” benchmarks: if such a nexus exists between illegal activity and the place to be searched, the affidavit is not bare bones and reliance is reasonable.

B. Legal Reasoning

1. The appeal waiver foreclosed review of the plea-vacatur denial

The panel’s waiver reasoning is straightforward and textual. Burrus’s plea agreement broadly waived the right to appeal his conviction and sentence, preserving only narrow exceptions: certain sentencing challenges (if the sentence exceeded the statutory maximum or resulted from an upward departure) and the denial of the two suppression motions. The motion to vacate the guilty plea did not fit those carve-outs.

The court then anchored “knowing and voluntary” in two sources: (i) the written agreement (Burrus’s signed representations) and (ii) the plea colloquy, where the district court questioned Burrus about the agreement and forfeited rights and Burrus affirmed understanding and voluntariness. Under Ellis, those sworn statements are a “formidable barrier” to later claims of misunderstanding. Because both prongs of Milliron were met, the appellate court declined to reach the merits of the plea-vacatur argument.

2. Good-faith reliance under Leon disposed of the suppression challenges

Burrus attacked probable cause on multiple fronts (informant reliability, staleness, nexus, K9 reliability). The court largely sidestepped disputed probable-cause details by applying Leon: even if probable cause were borderline, suppression is unwarranted unless the affidavit is “bare bones” or otherwise makes reliance objectively unreasonable.

a. Phone records warrant

The court found the affidavit contained multiple factual anchors: the affiant’s experience; statements from J.O.’s mother and boyfriend identifying “Yay” and the number ending in 7846 as the source of drugs; investigative corroboration that the number contacted other known drug dealers; and an undercover call where the answering man refused to sell only because he did not recognize the caller “as a usual customer,” which the court treated as confirmatory of drug-sales usage. This was enough to defeat any characterization as “bare bones” under Christian and White.

b. Residence warrant (3038 Brookdale)

The affidavit linked “Yai” to the residence through informant information and then added police surveillance: Burrus leaving the residence in the described vehicle, meeting individuals, exchanging unknown objects for cash, slow driving patterns, and returning home with cash—behavior officers attested was indicative of trafficking. Even if Burrus contested the nexus, the panel held this supplied at least a “modicum of evidence” connecting drug trafficking to the home, making officer reliance reasonable under Carpenter/Laughton/White.

c. Storage unit warrants and the K9 “false alert”

The affidavits connected the units to Burrus via: items found at the residence (drugs, cash, and a “Move N Store” key), the inference the key belonged to a storage unit, identification of Burrus by U-Store employees as paying for units in cash, and a lock brand matching the key. The K9 “Rocky” alerted to two units; one alert corresponded to an empty unit, which Burrus argued showed unreliability. The court nevertheless treated the overall showing—plus the affiant’s training/experience statement that traffickers use storage units to conceal evidence—as sufficient to support a good-faith belief in the warrants’ validity. In short, a later-discovered empty unit did not retroactively render reliance unreasonable.

C. Impact

  • Reinforcement of broad appeal-waiver enforcement: The decision underscores that, when the plea agreement preserves only certain issues (here, suppression rulings and narrow sentencing claims), appellate courts will enforce the waiver as written and will not entertain collateral challenges framed as “plea withdrawal/vacatur” unless explicitly preserved.
  • Leon as a practical “gatekeeper” in warrant litigation: The panel’s approach illustrates that suppression appeals often turn less on whether probable cause was perfect and more on whether the affidavit was so deficient that reliance was objectively unreasonable. This incentivizes litigants to focus on the “bare bones” threshold and not merely on arguable weaknesses (e.g., informant credibility or staleness) when good faith is likely available.
  • Nexus requirement in good-faith terms: By repeatedly invoking “a modicum of evidence” and “minimally sufficient nexus,” the opinion signals that modest corroboration (surveillance consistent with trafficking, linkage items like keys/locks, payment records, admissions on calls) will frequently suffice to preserve evidence under Leon, even if contested on probable-cause grounds.
  • K9 imperfections may not defeat good faith: The opinion suggests that a K9 alert that proves inaccurate as to one unit does not necessarily invalidate reliance on a warrant when other connecting facts exist; defendants will likely need stronger showings (e.g., known systemic unreliability, material omissions, or reckless misstatements) to overcome good faith.

IV. Complex Concepts Simplified

  • Appeal waiver: A contractual term in a plea agreement where the defendant agrees not to appeal (or to appeal only limited issues). Courts generally enforce it if the defendant understood it and entered it voluntarily.
  • Plea colloquy: The in-court questioning by the judge to ensure the defendant understands the plea’s consequences and is pleading voluntarily. Statements made under oath here strongly undermine later claims of confusion.
  • Probable cause: A “fair probability” that evidence of a crime will be found in the place to be searched. It is a practical, common-sense standard, not proof beyond a reasonable doubt.
  • Nexus: The connection between (a) the suspected criminal activity and (b) the specific place or data to be searched. For good-faith purposes, the Sixth Circuit asks whether there is at least a minimal factual bridge.
  • “Bare bones” affidavit: An affidavit that contains only conclusions or suspicions with no real facts showing why probable cause exists. If an affidavit is truly bare bones, officers cannot reasonably rely on it and Leon does not save the search.
  • Leon good-faith exception: Even if a warrant is later found lacking probable cause, evidence is usually not suppressed if officers reasonably relied on the warrant issued by a magistrate.
  • Staleness: The idea that old information may no longer support probable cause because circumstances could have changed. In this case, the court did not need to resolve staleness because it upheld admissibility under Leon.

V. Conclusion

United States v. Claibon Burrus delivers two practical rules. First, a properly executed appeal waiver will be enforced according to its terms, barring appellate review of issues (like denial of a plea-vacatur motion) not expressly preserved. Second, in warrant challenges, the Sixth Circuit will often resolve suppression disputes through United States v. Leon: if affidavits provide at least a minimal, fact-based nexus—and are not “bare bones”—officers’ reliance is objectively reasonable and suppression is unavailable, even where defendants point to informant issues, staleness arguments, or an imperfect K9 alert.