The Supreme Court on Monday gave law enforcement officers new authority to enter a home without a warrant when they have reason to believe that drug evidence is being destroyed.

The court ruled 8 to 1 that Kentucky police who smelled marijuana at an apartment door, knocked loudly and announced themselves, and then kicked in the door when they thought the drugs were being destroyed did nothing wrong.

Justice Samuel A. Alito Jr., writing for the majority, said the conduct of the police before they entered the apartment was “entirely lawful” and neither violates nor threatens a person’s Fourth Amendment protection against unreasonable searches or seizures.

Justice Ruth Bader Ginsburg strongly disagreed.

“The court today arms the police with a way routinely to dishonor the Fourth Amendment’s warrant requirement in drug cases,” Ginsburg wrote. “In lieu of presenting their evidence to a neutral magistrate, police officers may now knock, listen, then break the door down, nevermind that they had ample time to obtain a warrant.”

Generally, the Constitution requires police to receive permission or obtain a warrant before entering someone’s home, which Ginsburg called “our most private space.” But the court has recognized exceptions in “exigent” circumstances: For instance, when a life might be endangered, a suspect might escape or evidence might be destroyed.

Lexington police said that was the case with defendant Hollis King. Police entered his apartment complex looking for a different man they had spotted selling drugs. They had a choice of two apartments into which the man could have entered, and picked one when they smelled marijuana.

They knocked loudly, announced “Police, police, police” and then knocked down the door when they heard activity inside the apartment that they interpreted as attempts to dispose of the evidence. They found King and others smoking marijuana, plus other drugs and money. (The original suspect, who was in a different apartment, was arrested but never convicted.)

King was convicted, but the Kentucky Supreme Court said the judge in the case should have suppressed the evidence. The state justices said police had created the emergency circumstances that they used to justify their failure to get a warrant to enter the apartment.

But Alito said the police did nothing wrong. If officers don’t create the emergency “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.”

He said King could have told police they could not enter. “Occupants who choose not to stand on their constitutional rights but instead elect to attempt to destroy evidence have only themselves to blame” when police force their way in, he said.

Alito said an exigent circumstance might not exist if police “without a warrant or any legally sound basis for a warrantless entry, threaten that they will enter without permission unless admitted.”

The case is Kentucky v. King.

Whistleblower claims

The court made it harder for whistleblowers to bring lawsuits alleging corporate wrongdoing when they use government information to support their claims.

By a 5 to 3 vote, the court stopped a lawsuit brought under the federal False Claims Act based on information that Daniel and Linda Kirk obtained through a Freedom of Information Act request.

The False Claims Act allows private citizens to bring civil lawsuits against companies in the government’s name, and receive a share of any money recovered. In this case, Daniel Kirk said his former employer, Schindler Elevator, had violated the terms of its government contracts involving reports about the employment of Vietnam veterans.

But the False Claims Act does not allow lawsuits based on information disclosed in public reports. Justice Clarence Thomas, writing for the majority, said Congress was concerned that private citizens not base their complaints on information the government itself generated.

“The sort of case that Kirk has brought seems to us a classic example of the ‘opportunistic’ litigation that the public disclosure bar is designed to discourage,” Thomas wrote. “Although Kirk alleges that he became suspicious from his own experiences as a veteran working at Schindler, anyone could have filed the same FOIA requests and then filed the same suit.”

Thomas was joined by Chief Justice John G. Roberts Jr. and Justices Antonin Scalia, Anthony M. Kennedy and Alito.

Ginsburg dissented, along with Justices Stephen G. Breyer and Sonia Sotomayor.

“Why should a whistleblower . . . be barred from court if he seeks corroboration for his allegations?” Ginsburg asked.

“After today’s decision, which severely limits whistleblowers’ ability to substantiate their allegations before commencing suit, that question is worthy of Congress’s attention,” she said.

Justice Elena Kagan did not take part in the case because she had worked on it in her previous job as solicitor general.

The case is Schindler Elevator Corp. v. United States, ex rel. Kirk.