The ruling comes the same day President Barack Obamafederal appeals judge Sonia Sotomayor to the replace retiring Justice David Souter.
In a 5-4 ruling, the high court overturned the 1986 Michigan v. Jackson ruling, which said police may not initiate questioning of a defendant who has a lawyer or has asked for one unless the attorney is present.
The Michigan ruling applied even to defendants who agree to talk to the authorities without their lawyers.
The court's conservatives overturned that opinion Tuesday, with Justice Antonin Scalia saying "it was poorly reasoned, has created no significant reliance interests and (as we have described) is ultimately unworkable."
Scalia, who read the opinion from the bench, said their decision will have a "minimal" effects on criminal defendants. "Because of the protections created by this court in Miranda and related cases, there is little if any chance that a defendant will be badgered into waiving his right to have counsel present during interrogation," Scalia said.
The Michigan v. Jackson opinion was written by Justice John Paul Stevens, the only current justice who was on the court at the time. He dissented from the ruling, and in an unusual move read his dissent aloud from the bench. It was the first time this term a justice had read a dissent aloud.
"The police interrogation in this case clearly violated petitioner's Sixth Amendment right to counsel," Stevens said. Overruling the Jackson case, he said, "can only diminish the public's confidence in the reliability and fairness of our system of justice."
The decision comes in the case of Jesse Jay Montejo, was found guilty in 2005 of the shooting death of Louis Ferrari in the victim's home on Sept. 5, 2002.
He was appointed a public defender at his Sept. 10, 2002 hearing, but was never indicated that he accepted the lawyer's help. Montejo then went with police detectives to help them look for the murder weapon. While in the car, Montejo wrote a letter to Ferrari's widow incriminating himself.
When they returned to the prison, a public defender was waiting for Montejo, irate that his client had been questioned without him being present.
Montejo was convicted and sentenced to death. He appealed, but the Louisiana Supreme Court upheld the conviction and sentence.