In September 2021, law enforcement officers in Anaconda, Montana, entered the home of William Trevor Case after his ex-girlfriend reported he had threatened suicide, was acting erratically and may have fired a gun. When Case appeared to reach for a weapon, an officer shot him. Case was convicted of assaulting an officer, and the Montana Supreme Court affirmed his conviction, saying the officers properly entered Case’s home based on objective, verifiable facts that he could be in danger.

Case appealed to the Supreme Court, arguing the Fourth Amendment requires police to have probable cause rather than reasonable suspicion of a need to render emergency aid before entering a home.

The Fourth Amendment requires that all government searches and seizures be “reasonable” and that magistrates may only issue warrants supported by probable cause, according to Molly McInnis, associate member of the University of Cincinnati Law Review.

Maclin said the ruling is “consistent with this court’s very conservative, narrow approach to the Fourth Amendment.” The amendment’s framers would never have allowed police officers to enter a home, “which they considered the most sacred place,” without probable cause, he said.

Justice Elena Kagan wrote in the opinion that the “very core” of the Fourth Amendment is “the right of a man to retreat into his own home and there be free from unreasonable intrusion.” While reasonableness “usually means having a warrant,” she wrote, that is subject to exceptions. “And among those is one pertinent here, involving the need to provide an occupant with emergency aid.”

In an amicus brief filed by a coalition including the National League of Cities and National Association of Counties, the civic groups argued that welfare checks and crisis calls “are a central function of modern policing” and imposing a probable cause requirement “would impede public safety and endanger lives.”

“We knew at the time our officers did the right thing in trying to help one of our citizens,” Anaconda-Deer Lodge Police Chief Bill Sather said in a statement. “Today’s decision makes it much easier for officers to do their job.”

Case v. Montana “creates a new situation in which police can forcibly enter private homes without warrants,” the Constitutional Accountability Center said in a statement. “It remains to be seen whether the Court’s alternative standard — police must have an ‘objectively reasonable basis for believing’ that an emergency is occurring — is rigorous enough to prevent officers from using emergency aid as a pretext for home intrusions spurred by other motives.”

Matthew Cavedon, director of the Cato Institute’s Project on Criminal Justice, said in a statement that Justice Neil Gorsuch’s concurring opinion “reiterated that emergency aid entries are not an excuse to search for evidence of criminal activity.” Cavedon said the decision “rightly clarified that home entries should not be undertaken lightly.”