Whether officers may enter a home without a warrant when they have an objectively reasonable basis to believe an occupant is seriously injured or imminently threatened with serious injury.
Holding
Yes. The officers' warrantless entry was reasonable under the Fourth Amendment because they had an objectively reasonable basis to believe that an injured person might need aid and that further violence was imminent.
Reasoning
Warrantless entries into a home are presumptively unreasonable, but the Fourth Amendment's ultimate standard is reasonableness. One established exigency permits officers to enter without a warrant to render emergency assistance to an injured occupant or to protect an occupant from imminent injury.
The officers confronted a live, escalating disturbance rather than a completed offense. At 3 a.m., they heard loud fighting, crashing, and pleas to stop. From the backyard, they saw adults struggling with a juvenile, then saw the juvenile strike an adult hard enough to make the adult spit blood. Those facts objectively supported a belief that the injured adult could need help and that more violence could follow.
The Fourth Amendment did not require the officers to wait for someone to become unconscious, semiconscious, or more severely injured. Police may act to prevent violence and restore order, not merely provide aid after a serious injury has already occurred.