The following editorial appeared in the Los Angeles Times on Friday, Nov. 15:

Seven years ago, the Supreme Court rightly ruled that police couldn’t conduct a warrantless search of a home shared by two people if one of the residents was present and objected. This week, the justices heard arguments in a case from California that threatens to make that decision a dead letter.

The court should reject the argument that police can get around a resident’s objection to a warrantless search by arresting him and then seeking permission from his spouse or roommate.

That’s what occurred in 2009 when police tracked a suspect in a robbery to a Los Angeles apartment. A woman who showed signs of having been beaten opened the door, and then Walter Fernandez appeared and objected to a search of the premises, saying, “I know my rights.” Concerned about possible domestic violence, police took Fernandez into custody and arrested him on robbery charges. Later they returned to the apartment, where the woman gave them permission to conduct a search. It turned up gang paraphernalia, a knife and a gun.

Fernandez was convicted of robbery and domestic abuse and received a 14-year sentence. But on Wednesday, his lawyer argued that the search of Fernandez’s apartment was illegal under Georgia v. Randolph, the 2006 decision in which the court ruled that police couldn’t search a married couple’s house for illegal drugs after the husband objected — even though his wife had agreed.

At Wednesday’s argument, Justice Sonia Sotomayor remarked that upholding Fernandez’s conviction would mean that “there’s nothing left to Randolph; the police just remove the person.” A lawyer for the state of California suggested that there might be a difference between a valid arrest, such as the one in this case, and a ruse by police to lure a suspect away from his residence so that they could obtain a roommate’s permission for a search. But given the ease with which police can place someone under arrest, that distinction doesn’t offer much reassurance.

Sotomayor is right. If the court meant what it said in 2006 — that a warrantless search can’t occur if one resident is on the scene and objects — then it must rule for Fernandez. Such a ruling wouldn’t make it impossible for police to search the premises of people they have probable cause to believe committed a crime. As Fernandez’s lawyer pointed out, it takes only 15 minutes on average for police in Los Angeles to obtain a warrant via telephone. But it would make it less likely that police who lack probable cause would be able to invade the privacy of one citizen on the say-so of another.