Monell Liability Requires an Underlying Fourth Amendment Violation: Hearsay (Including Double Hearsay) Can Support Probable Cause Under Jones

1. Introduction

In Mendenhall v. City and County of Denver (10th Cir. Jan. 16, 2026), plaintiff-appellant Michael Mendenhall brought a municipal-liability action under 42 U.S.C. § 1983 against the City and County of Denver (“Denver”), challenging a search warrant used to search his townhome and seize a baseball bat after a third party reported that Mendenhall threatened him.

The central issue was not whether the warrant application contained hearsay—it did—but whether the use of hearsay (and “double hearsay”) to establish probable cause can itself constitute a Fourth Amendment violation sufficient to support municipal liability under Monell v. Dep't of Social Servs., 436 U.S. 658 (1978). Mendenhall candidly framed the case as a “test case” designed to challenge and “ultimately overturn” Jones v. United States, 362 U.S. 257 (1960), which permits reliance on informant information (i.e., hearsay) in probable-cause determinations.

2. Summary of the Opinion

The Tenth Circuit affirmed the district court’s dismissal at the pleading stage. The court held that controlling Supreme Court authority—Jones v. United States—permits officers to rely on hearsay in warrant applications, and Tenth Circuit precedent likewise recognizes that even multiple layers of hearsay may support probable cause. Because the alleged conduct (using hearsay to support probable cause) was constitutionally permissible under binding precedent, Mendenhall failed to plausibly allege an underlying constitutional violation. Without an underlying constitutional violation by a municipal employee, a Monell claim fails as a matter of law.

The court also emphasized institutional limits: lower federal courts must follow Supreme Court precedent even if a litigant seeks its reconsideration; any change must come from the Supreme Court.

3. Analysis

3.1. Precedents Cited

  • Monell v. Dep't of Social Servs., 436 U.S. 658 (1978)
    Role in the decision: The foundation for municipal liability under § 1983. The panel treated Monell as requiring a constitutional tort attributable to an official policy/custom (or a facially constitutional policy causing a violation). Here, because the pleaded “violation” was not a violation under controlling Fourth Amendment doctrine, Monell never got off the ground.
  • Burke v. Regalado, 935 F.3d 960 (10th Cir. 2019)
    Role in the decision: Quoted for the critical gating principle: “a municipality may be liable only if a municipal actor committed a constitutional violation.” This case supplied the doctrinal bridge from the Fourth Amendment issue to the failure of the municipal-liability claim.
  • Finch v. Rapp, 38 F.4th 1234 (10th Cir. 2022)
    Role in the decision: Provided the three elements of a Monell claim—(1) official policy/custom, (2) causation, (3) deliberate indifference—reinforcing that a plaintiff must clear multiple hurdles, beginning with an underlying constitutional violation.
  • Hinton v. City of Elwood, 997 F.2d 774 (10th Cir. 1993)
    Role in the decision: Directly supported dismissal by stating that the absence of an underlying constitutional violation by city officers “precludes the imposition of any liability against” the municipality under Monell.
  • Jones v. United States, 362 U.S. 257 (1960)
    Role in the decision: The dispositive Fourth Amendment precedent. The panel relied on Jones for the rule that an officer may rely on informant information (hearsay) in a warrant application, so long as it is “reasonably corroborated by other matters within the officer's knowledge.” Because Mendenhall’s theory treated hearsay itself as unconstitutional, Jones foreclosed the claim.
  • United States v. One Hundred Forty-Nine Thousand Four Hundred Forty-Two & 43/100 Dollars ($149,442.43) in U.S. Currency, 965 F.2d 868 (10th Cir. 1992)
    Role in the decision: Reinforced within-circuit acceptance of hearsay—and “perhaps multiple hearsay”—as a permissible basis to establish probable cause for a search warrant.
  • United States v. Mathis, 357 F.3d 1200 (10th Cir. 2004)
    Role in the decision: Strengthened the court’s response to “double hearsay” arguments by explicitly restating that multiple layers of hearsay may support a finding of probable cause.
  • Hutto v. Davis, 454 U.S. 370 (1982) and Jewell v. United States, 749 F.3d 1295 (10th Cir. 2014)
    Role in the decision: These cases anchored the panel’s institutional point: lower courts are bound by Supreme Court precedent. The panel used them to explain why it would not entertain a merits-based invitation to “overturn” Jones.
  • Johnson v. Smith, 104 F.4th 153 (10th Cir. 2024)
    Role in the decision: Set the appellate standard of review for a motion to dismiss (de novo, accepting well-pleaded allegations as true and viewing them favorably to the plaintiff). Even under that plaintiff-friendly lens, binding Fourth Amendment doctrine defeated the claim.
  • United States v. Salvucci, 448 U.S. 83 (1980)
    Role in the decision: Mentioned only to clarify that Jones has an overruled “automatic standing” component, but that the overruled portion is not relevant here. The court thereby insulated its reliance on the still-valid portion of Jones concerning hearsay and probable cause.

3.2. Legal Reasoning

The court’s reasoning proceeded in a structured sequence typical of § 1983 municipal-liability cases:

  1. Identify the alleged constitutional violation.
    Mendenhall alleged the Fourth Amendment was violated because the warrant rested on hearsay (indeed, “double hearsay”): the complainant’s statements and the officer’s relay of those statements in the affidavit.
  2. Apply controlling Fourth Amendment precedent to determine whether the pleaded facts describe unconstitutional conduct.
    The panel treated Jones v. United States as dispositive: hearsay can support probable cause in a warrant application. The court then confirmed that Tenth Circuit cases ($149,442.43 in U.S. Currency and Mathis) likewise allow multiple layers of hearsay to support probable cause.
  3. Conclude there is no plausible underlying constitutional violation.
    Because hearsay-based probable cause is constitutionally permissible, the complaint did not plausibly allege that any Denver officer violated the Fourth Amendment by using hearsay to obtain the warrant and seize the bat.
  4. Apply the Monell “no violation, no municipal liability” rule.
    Under Burke v. Regalado and Hinton v. City of Elwood, the absence of an underlying constitutional violation forecloses municipal liability. Thus, the court affirmed dismissal without reaching broader Monell elements (policy/custom, causation, deliberate indifference) in any depth.
  5. Reinforce the hierarchy-of-courts constraint.
    Invoking Hutto v. Davis and Jewell v. United States, the panel emphasized that a litigant’s strategic goal of overturning Supreme Court precedent cannot be realized in a circuit court.

3.3. Impact

Although the disposition is labeled an “Order and Judgment” and “not binding precedent” (except under law-of-the-case, res judicata, and collateral estoppel), it carries clear persuasive implications for Fourth Amendment and municipal-liability litigation in the Tenth Circuit:

  • Hearsay-based warrant challenges face an immediate doctrinal barrier. Plaintiffs who frame hearsay (even multilayer hearsay) as inherently unconstitutional will likely be dismissed at the pleading stage because Jones and Tenth Circuit cases treat hearsay as a permissible ingredient in probable cause.
  • Monell claims remain structurally dependent on an underlying constitutional violation. The decision underscores a practical litigation sequence: unless the plaintiff can plead facts showing an officer committed a constitutional tort, courts will not proceed to policy/custom and deliberate-indifference inquiries.
  • “Test case” strategies must account for vertical stare decisis. The opinion is a direct reminder that lower courts will not entertain invitations to overrule Supreme Court holdings; litigants must preserve arguments for Supreme Court review rather than expecting doctrinal innovation at the circuit level.

4. Complex Concepts Simplified

  • Probable cause (search warrant context): A “fair probability” that evidence of a crime will be found in the place to be searched. It does not require proof beyond a reasonable doubt.
  • Hearsay vs. “double hearsay” in warrant affidavits: “Hearsay” is information the affiant officer learned from someone else. “Double hearsay” adds another layer (e.g., A tells B, and B tells the officer). Under Jones and Tenth Circuit precedent, hearsay—even multiple layers—can contribute to probable cause.
  • Monell claim (municipal liability): A city is not automatically liable for its employees’ actions. A plaintiff must show an underlying constitutional violation and that the violation was caused by an official policy/custom (and typically deliberate indifference).
  • Vertical stare decisis: Lower courts must follow Supreme Court precedent. Even if a litigant argues a Supreme Court case is wrong, the circuit court must apply it unless and until the Supreme Court changes it.
  • Motion to dismiss (Rule 12(b)(6)) and de novo review: At the dismissal stage, the court assumes the complaint’s well-pleaded facts are true but asks whether they plausibly state a legal claim. On appeal, “de novo” means the appellate court reviews the issue fresh, without deferring to the district court.

5. Conclusion

Mendenhall v. City and County of Denver reinforces two settled propositions: (1) under Jones v. United States and Tenth Circuit authority, hearsay—including multiple layers of hearsay—may support probable cause for a search warrant; and (2) a Monell municipal-liability claim fails absent a plausible allegation of an underlying constitutional violation by a municipal employee. The decision also serves as a procedural and institutional reminder: lower federal courts will apply controlling Supreme Court precedent, leaving doctrinal change to the Supreme Court itself.