NACo Legal Advocacy: William Trevor Case v. State of Montana

County Nexus 

Counties and their law enforcement partners are on the front lines of responding to emergency-aid situations that include mental and behavioral health crises, welfare checks, and calls involving vulnerable residents every day. The question at hand in William Trevor Case v. State of Montana is how the “emergency-aid” exemption to the Fourth Amendment is defined and whether it should require “probable cause,” a higher legal threshold that would be needed to justify officers entering the premises of a home in an emergency-aid scenario. 

Background

In September 2021, law enforcement in Anaconda–Deer Lodge County, Montana, received a 911 call from the petitioner’s ex-girlfriend reporting that he was suicidal and had threatened to shoot responding officers if they came to his home. The call went silent, and she could not reach him again. Officers arrived, observed a quiet scene, and were unable to make contact. Concerned that he might have harmed himself, they entered the home without a warrant under the emergency-aid doctrine. Inside, they encountered the petitioner and ultimately recovered evidence that led to criminal charges.

William Trevor Case, the petitioner, moved to suppress the evidence, arguing that the officers violated the Fourth Amendment because they did not have probable cause of an actual emergency before entering his home. The trial court denied the motion, and a jury convicted him. The Montana Supreme Court, in a 4–3 decision, affirmed the conviction and held that officers need an “objectively reasonable basis,” not “full probable cause,” to believe someone inside needs help in order to enter a home without a warrant under the emergency-aid exception. In practical terms, the U.S. Supreme Court is deciding whether the emergency-aid exception uses: A) a flexible “objectively reasonable basis” standard (as many courts have applied), or B) a more demanding “probable cause of an emergency” standard before officers may enter a home to render aid. 

NACo Advocacy 

In a Local Government Legal Center (LGLC) amicus brief in support of the plaintiff-appellees, LGLC argues that the Fourth Amendment’s “ultimate touchstone” is overall reasonableness, not a single, one-size-fits-all probable cause rule, which is strongly supported in the Court’s own precedents. In emergency-aid situations, where officers are responding to potential threats to life or safety rather than conducting a traditional criminal investigation, we argus that it is appropriate to use a different threshold: an objectively reasonable basis to believe someone inside needs immediate help. The brief further explains that many real-world welfares checks, and crisis calls are based on incomplete information, like silence after a suicide threat, a missing elder, or a distressed hotline call, which often do not rise to classic probable cause justification, yet clearly demand an immediate response.  

Requiring probable cause in these situations would discourage early intervention, delay life-saving action, and pressure agencies to reframe health and welfare calls as criminal investigations. We warn that such a rule would create perverse incentives and greater liability risk for counties, undermining co- and crisis-response models that depend on quick action concluding that preserving the current “objectively reasonable basis” standard best protects both residents and local governments by allowing officers to act when there are reasonable indicators of danger while still respecting home privacy and maintaining community trust. Shifting to a strict probable cause requirement would break from decades of Supreme Court precedent and undermine community trust by limiting the ability of counties to respond when residents call for emergency help.  

Current Status

William Trevor Case v. State of Montana was argued before the U.S. Supreme Court on October 15, 2025, and remains pending. A decision is expected by June 2026, before the end of the Court’s October 2025 term.

Through the Local Government Legal Center, NACo will continue to monitor the case, provide updates to counties, and analyze what the Court’s eventual ruling means for local crisis-response practices, co-responder models, and county liability in emergency-aid situations.