The U.S. Supreme Court on Monday declined to hear a case exploring the limits of the "protective sweep doctrine," which allows law enforcement officers to conduct limited warrantless searches of homes they have lawfully entered. 

The case stemmed from a warrantless search police conducted of David McMaster's home after they arrested him in a neighbor's backyard as he was "excited, incoherent, naked, and appeared to be under the influence of a controlled substance," according to McMaster's petition for certiorari.

A detective entered McMaster's home, purportedly to perform a "protective sweep" to search for others who may have needed medical help. However, McMaster had told police that no one else was in his home, and there was no evidence to the contrary, according to the petition.

During the search, a police officer found "vegetation" that appeared to be a controlled substance, prompting officers to obtain a search warrant. They later recovered psilocybin mushrooms and marijuana, among other items, resulting in criminal charges against McMaster.

A trial court later suppressed evidence from the search of McMaster's home, saying officers' entry and search of the home was illegal and not valid under the protective sweep or emergency aid doctrines. Pennsylvania appealed the ruling, and a Pennsylvania appellate court reversed the decision, saying the detective's initial search of the home was lawful as a "minimally intrusive protective sweep," according to the petition. After the Pennsylvania Supreme Court declined to hear his appeal, McMaster filed his petition with the nation's highest court.

In his petition for certiorari, McMaster argued that there was not enough evidence to justify even the protective sweep.

"Pointedly, there was no objective basis to conclude that another person was inside McMaster's house, let alone someone in danger," according to the petition, which was filed in June.

The court's denial of certiorari in McMaster comes roughly a month after it heard oral arguments in Case v. Montana, a case that tests the limits of the emergency aid doctrine — the standard for when police may enter a person's home without a warrant to address a potential emergency. The court has not ruled in that case. 

McMaster is represented by Heidi Freese, Barbara Zemlock and J. Andrew Salemme of Tucker Arensberg PC.

The government is represented by Robert Bain II of the Office of the Adams County District Attorney.

The case is David A. McMaster Jr. v. Commonwealth of Pennsylvania, case number 24-1244, in the Supreme Court of the United States.

--Editing by Rich Mills.