Troyer

“[T]he ‘physical entry of the home is the chief evil against which the wording of the Fourth Amendment is directed.’ ” (Payton v. New York (1980) 445 U.S. 573, 585 [ 63 L.Ed.2d 639 , 100 S.Ct. 1371 ].) Thus, “searches and seizures inside a home without a warrant are presumptively unreasonable.” (Id. at p. 586.) “Nevertheless, because the ultimate touchstone of the Fourth Amendment is ‘reasonableness,’ the warrant requirement is subject to certain exceptions.” (Brigham City v. Stuart (2006) 547 U.S. 398, 403 [ 164 L.Ed.2d 650 , 126 S.Ct. 1943 ].) In particular, “law enforcement officers may enter a home without a warrant to render emergency assistance to an injured occupant or to protect an occupant from imminent injury.” (Ibid.)

In this case, both the trial court and the Court of Appeal found the record sufficient under the emergency aid exception to justify a warrantless entry by police into a residence to search for additional victims of a recent shooting. The Court of Appeal, however, reversed the judgment because it found the police erred in entering a locked upstairs bedroom, where marijuana, related paraphernalia, and firearms were found in plain view. Because the…