Comparative Negligence in Jail-Custody Cases: Estate of Mabee v. Wheatland County Confirms “Special Circumstances” as the Exception

Introduction

In Estate of Mabee v. Wheatland County, 2025 MT 252, the Montana Supreme Court clarifies a pivotal question at the intersection of custodial care and tort law: when may a jailer invoke the defense of comparative negligence against a detainee (or the detainee’s estate) in a negligence action? The Court affirms that, as a general rule, comparative negligence applies in jailer–detainee cases in Montana; however, an important exception exists. Where “special circumstances” are present—namely, when the jailer knows or has reason to know the detainee faces a particular risk of harm—the jailer’s duty to act becomes paramount and the detainee’s comparative negligence is not to be weighed.

The case arises from the tragic death of Richard Mabee, who overdosed on methamphetamine while in the Wheatland County Jail. His Estate alleged negligence in failing to provide adequate medical care; the County defended, in part, by asserting Mabee’s comparative negligence. The district court allowed the jury to apportion fault, which it did—assigning 95% to Mabee and 5% to the County—precluding recovery under Montana’s more-than-50% bar. On appeal, the Estate argued that comparative negligence should not apply at all in a jailer–detainee context. The Supreme Court disagreed, while carefully delineating the governing exception for “special circumstances.”

• Court: Supreme Court of Montana
• Date: November 4, 2025
• Citation: 2025 MT 252 (DA 24-0554)
• Parties: Estate of Richard Mabee (Appellant) v. Wheatland County and Wheatland County Sheriff’s Office (Appellees)
• Disposition: Affirmed

Summary of the Opinion

The Montana Supreme Court affirms judgment for the County. It holds that under Montana law, comparative negligence is available to a jailer as an affirmative defense in negligence actions arising from the jailer–detainee relationship except where “special circumstances” exist. Special circumstances arise when the jailer knows or should know the detainee is at risk of a particular harm, including self-inflicted harm. In those situations, the jailer’s elevated duty to protect supersedes the detainee’s duty to protect themselves, and comparative negligence is not appropriate. Because the Estate did not preserve a jury-instruction challenge to define and invoke this special-circumstances exception at trial, the Court declines to decide whether the evidence could have supported that exception here and instead affirms the comparative-negligence apportionment and resulting judgment.

Core holding: A jailer may assert a detainee’s comparative negligence unless the jailer knew or should have known that the detainee was at risk of harm; if such “special circumstances” exist, the jailer’s duty to act becomes paramount and the detainee’s negligence is not compared.

Analysis

Precedents Cited and How They Shaped the Ruling

• Pretty On Top v. Hardin, 182 Mont. 311, 597 P.2d 58 (1979): The anchor Montana case on a jailer’s duty. It establishes:
  • General duty: A jailer must exercise reasonable and ordinary care to keep a prisoner safe, free from harm, render medical aid when necessary, and treat the prisoner humanely.
  • No liability for intentional self-harm absent “special circumstances.”
  • “Special circumstances” arise when the jailer knows or should know of a specific risk (e.g., suicide risk), elevating the jailer’s duty to take reasonable steps to prevent the foreseeable harm.
  The Court uses this framework to distinguish between ordinary jailer duty (where comparative negligence can be applied) and elevated duty (where it cannot).
• Giambra v. Kelsey, 2007 MT 158, 338 Mont. 19, 162 P.3d 134: Provides Montana’s articulation of comparative negligence and the more-than-50% bar, rooted in § 27-1-702, MCA. The Court leverages Giambra to underscore that, ordinarily, the factfinder compares the plaintiff’s and defendant’s negligence by reasonable-person standards.
• Bassett v. Lamantia, 2018 MT 119, 391 Mont. 309, 417 P.3d 299: Emphasizes that all persons owe a duty of reasonable care. The Court uses Bassett to explain why, under the general rule, the parties’ conduct can be compared: both parties owe independent duties of reasonable care.
• Sandborg v. Blue Earth County, 615 N.W.2d 61 (Minn. 2000), and Restatement (Second) of Torts § 452 cmt. d: These authorities support the proposition that in certain custodial scenarios, the duty to protect against a known possibility of self-inflicted harm “transfers entirely” to the custodian, making comparative fault inappropriate. The Montana Supreme Court cites Sandborg to corroborate its articulation of the special-circumstances exception.
• Peterson v. Eichhorn, 2008 MT 250, 344 Mont. 540, 189 P.3d 615: Cited to reinforce comparative negligence principles and the mechanics of comparing fault where parties owe separate duties.
• Standards of Review and Instructional Cases:
  • State v. Lynch, 2005 MT 337 (entitlement to assert an affirmative defense: de novo review).
  • Spotted Horse v. BNSF Ry. Co., 2015 MT 148 (jury-instruction review: abuse of discretion; instructions must fully and fairly reflect applicable law).
  • State v. Erickson, 2014 MT 304 (duty to instruct on issues supported by evidence).
  • Camen v. Glacier Eye Clinic, P.C., 2023 MT 174 (party must show prejudice from instructional error).
  • Vincent v. BNSF Ry. Co., 2010 MT 57 (failure to propose proper instructions forfeits challenge on appeal).
  • Bonilla v. Univ. of Mont., 2005 MT 183 (breach is a fact question for the jury).

The Court’s Legal Reasoning

• 1) Framing the duties: The Court begins from Pretty On Top’s baseline. Jailer duty is one of reasonable and ordinary care to keep the detainee safe and render medical aid as necessary. Under this baseline, the detainee still has a concurrent duty to exercise ordinary care for their own safety; thus, comparative negligence principles are potentially in play.
• 2) Integrating Montana’s comparative negligence scheme: Under § 27-1-702, MCA, a plaintiff cannot recover if more than 50% at fault; if less than 50% at fault, recovery is reduced in proportion to the plaintiff’s fault. The Court reiterates that comparative negligence compares the conduct of both parties based on reasonable-and-prudent-person standards (Giambra; Bassett).
• 3) Carving out the special-circumstances exception: Where the jailer knows or has reason to know of a particular risk of harm to the detainee (including self-inflicted harm), the jailer’s duty is elevated. In that setting, the detainee’s comparative negligence is not weighed because the duty to act rests predominately with the jailer. The Court explicitly aligns this with Pretty On Top and supportive authorities like Sandborg and the Restatement.
• 4) Rejecting the Estate’s proposed categorical bar: The Estate argued that the jailer–detainee relationship per se forecloses comparative negligence. The Court rejects this, noting it would contradict Pretty On Top’s framework. Instead, the correct approach distinguishes between the ordinary rule and the special-circumstances exception.
• 5) Application to the case: The Court concludes the trial court did not err in allowing the County to assert comparative negligence in the absence of a properly presented and preserved instruction defining “special circumstances.” The jury was correctly allowed to apportion fault, resulting in a 95/5 split against the Estate due to Mabee’s substantial share of fault.
• 6) Jury instructions and preservation: The Estate secured an instruction on the general jailer duty (Instruction No. 11) but did not propose an instruction explaining when “special circumstances” elevate that duty and preclude comparative negligence. The Court applies Vincent to hold that the Estate failed to preserve this issue for appellate review. It further holds there was no prejudice warranting reversal because the instructions, in context, allowed the Estate to argue foreseeability and the presence of “special need.”
• 7) Important clarifications: The Court notes it does not accept the County’s suggestion that its duty would become absolute only once it learned Mabee had a lethal dose of methamphetamine. The trigger is knowledge (actual or constructive) of risk of harm, not forensic certainty about lethality.

Impact

• Doctrinal clarity on comparative negligence in custody cases: The decision provides a clear, workable rule: comparative negligence is generally available to jailers, but it is foreclosed when the jailer knows or should know of the detainee’s specific risk of harm. This resolves uncertainty about whether incarceration alone bars comparative negligence.
• Heightened importance of “knowledge of risk” proof: Future plaintiffs must develop evidence that jail personnel had actual or constructive knowledge of a detainee’s particular risk (e.g., known intoxication, acute withdrawal, suicidal ideation, observable medical crisis) and that the risk was foreseeable. Personnel policies (e.g., hourly physical checks) and practitioner training, logs, video footage, prior familiarity with the detainee, and observed behavior will be central.
• Instructional practice and preservation: Trial counsel must request a precise instruction defining “special circumstances,” explaining how knowledge of risk elevates the duty and bars comparative negligence. Failure to do so risks forfeiting the argument on appeal, as occurred here.
• Operational and risk-management consequences for sheriffs and counties: Agencies should ensure policies for monitoring and intervention are followed and documented. Deviations from policy may supply “reason to know” evidence and feed the special-circumstances analysis. Training to recognize signs of overdose, withdrawal, or mental health crises—and to move from video-only monitoring to in-person checks—will be pivotal.
• Case selection and settlement dynamics: Where plaintiffs can plausibly meet the special-circumstances threshold, comparative negligence may drop out entirely, shifting settlement leverage. Where that threshold is doubtful, defendants will emphasize the general rule and the plaintiff’s conduct, knowing a 50%+ allocation to the detainee is case-dispositive.
• Beyond overdose cases: The opinion’s reasoning extends to other self-harm contexts (suicide, self-injury, complications from intoxication or withdrawal) and other custodial settings with analogous duties. The key remains whether the custodian knew or should have known of a specific risk.

Complex Concepts Simplified

• Comparative negligence: A system for allocating fault between plaintiff and defendant. In Montana (§ 27-1-702, MCA), a plaintiff who is more than 50% at fault recovers nothing; if 50% or less at fault, recovery is reduced by the plaintiff’s percentage of fault.
• Special circumstances (in the jailer–detainee context): Situations where the jailer knows or should know the detainee faces a particular, foreseeable risk of harm (including self-harm). When present, the jailer’s duty to protect is elevated and the detainee’s own negligence is not compared.
• Actual vs. constructive knowledge: “Knows” refers to what the jailer actually knew; “should have known” refers to what a reasonably prudent jailer would have recognized under the circumstances—through training, observations, policies, and available information.
• Affirmative defense: A legal defense that, even if the plaintiff proves the basic elements of negligence, can reduce or bar recovery. Comparative negligence is such a defense; entitlement to assert it is reviewed de novo on appeal.
• Preservation of error: To challenge jury instructions on appeal, a party must have proposed proper instructions or made specific objections at trial. Failure to do so generally forfeits the argument (Vincent).
• Foreseeability: A core concept in negligence assessing whether a reasonable person in the defendant’s position would have anticipated the risk of harm. In this case, foreseeability ties directly to whether “special circumstances” existed.

What the Court Did and Did Not Decide

• Decided:
  • Comparative negligence generally applies in jailer–detainee negligence claims.
  • Exception: when the jailer knew or should have known of the detainee’s risk, the jailer’s duty becomes paramount and the detainee’s negligence is not compared.
  • No reversible instructional error or prejudice occurred given the Estate’s failure to propose a special-circumstances instruction and the instructions’ overall adequacy.
• Not decided:
  • Whether the trial evidence in this case would have supported a finding that “special circumstances” existed (the issue was not preserved).
  • The precise contours of what specific facts amount to constructive knowledge in all scenarios; that remains fact-intensive.
  • Any categorical rule that incarceration alone eliminates comparative negligence—indeed, the Court rejected such a categorical bar.

Practice Guidance

• For plaintiffs: Build a record of actual or constructive knowledge—policy requirements (e.g., hourly in-person checks), past familiarity with the detainee, observable signs (e.g., shaking, disorientation, incoherent speech), training of personnel (e.g., EMT credentials), and any deviations from monitoring protocols. Propose a clear jury instruction defining “special circumstances,” explicitly stating that if such circumstances are found, comparative negligence should not be applied.
• For defendants: Emphasize the general rule of comparative negligence by showing that staff lacked knowledge (or reason to know) of a specific risk and that detainee conduct was an independent, unforeseeable cause. Preserve and request foreseeability and reasonable-person standard instructions. Document compliance with policies and timely responses to developing situations.
• For trial courts: Expect targeted instructions on “special circumstances.” Where evidence supports it, instruct the jury on both the baseline jailer duty and the heightened duty that precludes comparative negligence if knowledge or reason to know of risk is found.

Key Citations from the Opinion

• “A jailer owes a prisoner in his custody a duty ‘to keep the prisoner [safe] and free from harm, to render him medical aid when necessary, and to treat him humanely and refrain from oppressing him.’” (quoting Pretty On Top)
• “Special circumstances arise when the jailer knows or should know that the prisoner is at risk of harm … [and] must exercise reasonable care to protect the prisoner from that particular, foreseeable harm.”
• “Under these standards, a jailer may assert a detainee’s comparative negligence as a defense unless the jailer knew or should have known that the detainee was at risk of harm…”
• The Court rejects an “absolute” bar on comparative negligence in jailer–detainee cases and rejects a rule making the duty “absolute” only upon learning of a lethal dose; the trigger is knowledge of risk, not certainty about lethality.

Conclusion

Estate of Mabee v. Wheatland County establishes a clear, two-tier framework for Montana negligence claims arising from custodial settings. As a baseline, jailers and detainees are subject to the ordinary rules of comparative negligence because both owe duties of reasonable care. Yet when “special circumstances” exist—where the jailer knows or should know of a specific, foreseeable risk to the detainee—the jailer’s duty becomes paramount and the detainee’s negligence is not compared. This careful calibration preserves accountability for detainee conduct in ordinary circumstances while recognizing the heightened protective obligations that arise once risk becomes known or should be known to custodial authorities.

For practitioners, the case underscores the centrality of evidence and instructions. Plaintiffs must prove knowledge or reason to know of risk and must request instructions that operationalize the special-circumstances exception. Defendants, conversely, will focus on absence of knowledge and adherence to policy to maintain access to comparative negligence. As a result, Mabee will shape pleading, discovery, trial presentation, and jury instructions in Montana custodial-negligence litigation for years to come.