At about one o'clock in the morning, officers on patrol in La Mesa, Calif., received a radio call of an "unknown disturbance" involving a baseball bat in a residential street. Officer Stanton was familiar with the neighborhood, which was known for violence associated with gangs. When he and his partner arrived in a marked car, a group of three men started running or walking quickly away.
Stanton called out in a loud voice, "Police! Stop!" One of the men hurried through the gate to a nearby residence, which was surrounded by a high wooden fence. Stanton pursued, kicking open the gate and accidentally injuring resident Drendolyn Sims, who was standing behind the gate. She filed a federal lawsuit for illegal entry into the curtilage of her home, claiming a violation of her Fourth Amendment rights.
Attorneys for Officer Stanton asked the court to grant him qualified immunity, arguing as follows: (1) Under the Supreme Court ruling in Illinois v. Wardlow, police may detain a person based on unprovoked flight from police in a high-crime area. (2) A state statute made it a misdemeanor to resist a lawful detention. (3) The Supreme Court has held that a person may not defeat a lawful arrest by retreating into private premises. (U.S. v. Santana) Therefore, (4) officers were entitled to enter Sims's premises to prevent his escape from a lawful detention and arrest, albeit for a misdemeanor.
The trial court granted Officer Stanton qualified immunity, on the ground that no clearly established rule prohibited officers from making a warrantless entry into private premises to complete the detention or arrest of someone police lawfully attempted to detain or arrest in public, even though for a comparatively minor offense. The Ninth Circuit Court of Appeals reversed this ruling, declaring that it was "clearly established" that police may not enter private premises to complete an arrest when the underlying offense is a misdemeanor. In support of this ruling, the Ninth Circuit cited one of its own precedents, as well as the Supreme Court's ruling in Welsh v. Wisconsin.
On further appeal, the U.S. Supreme Court summarily and unanimously reversed the Ninth Circuit.