The police arrested the man, Walter Fernandez, on charges of domestic violence, and he was taken to the police station. An hour later, the police returned to the home and asked the woman, Mr. Fernandez’s girlfriend, if they could enter. She consented, and the subsequent search turned up a shotgun, ammunition and a knife allegedly used in the robbery.

Mr. Fernandez received an enhanced sentence of 14 years for the gang-related assault and robbery. He appealed, arguing that the enhancement was based on evidence collected in an unlawful search of his home. The state court rejected his appeal, finding that the police’s warrantless entry was legal because he was no longer there to object. Once he was gone, the state claimed that his girlfriend’s consent rendered the search lawful.

But there is no reason to complicate existing law in such circumstances. A tenant’s right to object to a warrantless search should not depend on whether he can permanently stand guard at his front door. If the police have probable cause to make an arrest, they will almost surely have the basis for a warrant as well. Warrants can be issued in a matter of minutes, and, in the meantime, the police can secure the home if they are concerned that evidence may be destroyed.

The state contends that obtaining consent is “simpler, faster and less burdensome” than getting a warrant. But that is precisely the point. By forcing the government to get a judge’s approval before intruding into a private home, the warrant requirement ensures oversight of law enforcement and informs citizens that the search has been authorized by a neutral arbiter.

The home, as the court has said, has long enjoyed “special protection as the center of the private lives of our people.” The justices should reaffirm that principle and require police who wish to search a home to get a warrant, even if the only person standing in their way is in a holding cell.