Police do not need a search warrant if, after knocking on a closed door and announcing their presence, they discern that evidence of a crime is being destroyed on the other side, the US Supreme Court ruled Monday.

In an 8-to-1 decision, the high court sought to clarify an exception to the Fourth Amendment’s requirement that police obtain a court-authorized search warrant before entering a private home.

The justices said in certain emergency circumstances a warrant is not necessary, provided that law enforcement officials act reasonably in compliance with Fourth Amendment protections and do not threaten to violate them.

The case involved a dispute over whether police in Lexington, Ky., were justified in the events that led to the arrest and conviction of Hollis King for drug trafficking.

Police were in pursuit of an individual who had just purchased crack cocaine during an undercover sting operation. Uniformed police officers followed the suspect into an apartment complex, but did not see which of two apartments he entered – the door on the right or the door on the left.

Strong odor of marijuana

As they approached, police noticed a strong odor of marijuana coming from under the door on the left. They assumed the suspect was hiding in that apartment. (In fact, he had entered the door on the right.)

Police knocked on the door on the left, announcing their presence. When no one answered, they pounded on the door. After hearing noises suggesting evidence was being destroyed, the police kicked the door open.

Once inside the apartment, they noticed marijuana and powder cocaine in open view. A subsequent search revealed crack cocaine, cash, and drug paraphernalia.

Mr. King was convicted of drug trafficking and sentenced to 11 years in prison. On appeal, his lawyer argued that the police violated King’s Fourth Amendment rights by failing to obtain a search warrant before entering the apartment.

Did police create the exigency?

An intermediate appellate court disagreed and upheld the conviction, but the Kentucky Supreme Court reversed. The state high court said that police could not rely on the so-called “exigent circumstances” exception to the warrant requirement when police themselves created the exigency used to justify the subsequent warrantless search.

In King’s case, the Kentucky Supreme Court said, the warrantless search of the apartment was improper because it was reasonably foreseeable by the police that the occupants of the apartment would start destroying evidence once officials banged on the door, and announced: “Police-police-police.”

That action would then create the emergency that would be used to justify breaking down the door and conducting the search without a warrant, the Kentucky high court said.

In reversing that decision on Monday, the US Supreme Court said the correct test is not whether the actions of police might trigger the attempted destruction of evidence. The proper test, the court said, is whether police conducted themselves in a reasonable manner prior to the emergency that required the warrantless search.

“Where, as here, the police did not create the exigency by engaging or threatening to engage in conduct that violates the Fourth Amendment, warrantless entry to prevent the destruction of evidence is reasonable and thus allowed,” wrote Justice Samuel Alito in the majority opinion.

“Occupants who choose not to stand on their constitutional rights but instead elect to attempt to destroy evidence have only themselves to blame for the warrantless exigent-circumstances search that may ensue,” he wrote.

Justice Alito drew the distinction between officers knocking on a door and announcing their presence versus a police officer threatening to kick down the door unless it is opened immediately. In the first example, if officers suddenly detected sounds of evidence being destroyed their warrantless entry would be justified. But in the second example, it would most likely not be justified, he said.

Justice Ginsburg is lone dissenter

In a lone dissent, Justice Ruth Bader Ginsburg said Monday’s decision would arm the police with a way to routinely by-pass Fourth Amendment search warrant requirements in drug cases.

“In lieu of presenting their evidence to a neutral magistrate, police officers may now knock, listen, then break the door down,” she said. “Never mind that they had ample time to obtain a warrant.”

Justice Ginsburg said that in her view the emergency cited by police to justify the warrantless search must already exist when police arrive at the scene, not subsequent to their arrival and prompted by their own conduct.

She said there was nothing in the record suggesting that police – before knocking – couldn’t have posted officers outside the residence while other officers sought a warrant authorizing their entry and search.

The Supreme Court decision establishes a rule for police conduct in situations in which an exigency exists. In King’s particular case, the Kentucky Supreme Court still needs to decide whether one existed. The high court remanded the case to decide that question. The case is Kentucky v. King (09-1272).