Family Law

The Supreme Court narrowed police search powers yesterday, ruling that officers must have a warrant to look for evidence in a couple's home unless both of the partners present agree to let them in.

The 5-to-3 decision sparked a sharp exchange among the justices. The majority portrayed the decision as striking a blow for privacy rights and gender equality; dissenters said it could undermine police efforts against domestic violence, the victims of which are often women.

The ruling upholds a 2004 decision of the Georgia Supreme Court, but still makes a significant change in the law nationwide, because most other lower federal and state courts had said police could search with the consent of one of two adults living together.

Now, officers must first ask a judicial officer for a warrant in such cases. Quarrels between husbands and wives or boyfriends and girlfriends keep police nationwide busy; in Washington, for example, almost half of the 39,000 violent crime calls officers answered in 2000 involved allegations of domestic violence.

Chief Justice John G. Roberts Jr., writing his first dissent since joining the court, said the ruling's ''cost" would be ''great."

Roberts wrote that the ruling made no sense, given that the court had previously said it is constitutional for police to enter a house with the permission of one partner when the other is asleep or absent. Those rulings were unchanged by yesterday's decision.

Just by agreeing to live with someone else, a co-tenant surrenders a good deal of the privacy that the Constitution's Fourth Amendment was designed to protect, Roberts said. ''The majority's rule apparently forbids police from entering to assist with a domestic dispute if the abuser whose behavior prompted the request for police assistance objects," he wrote.

The case arose out of a 2001 quarrel over child custody at the home of Janet and Scott Randolph in Americus, Ga. When officers arrived, she told them where they could find cocaine.

For more about the ruling, go to the Boston Globe.