Washington ? The Supreme Court refused on Tuesday to require special treatment for young people under questioning by police, ruling narrowly against a 17-year-old interrogated for two hours without being told of his rights.

The case set the stage for the court’s consideration this fall of the constitutionality of executing juvenile killers.

The justices voted 5-4 to reinstate a young man’s murder conviction and said police have no obligation to treat younger suspects differently from adults under the 1966 Miranda v. Arizona ruling that led to the warning that begins, “You have the right to remain silent.”

“The unfortunate result of this decision will be police circumventing the reading of Miranda warnings to children, the very class of persons who need to be informed of their rights the most,” said Tara Allen, the attorney for Michael Alvarado.

Police have to give warnings to people who are in custody. Warnings are not required if a suspect isn’t under arrest and talks to police.

That’s what police said Alvarado did when his parents brought him to a California police station. The parents were forced to wait outside the interrogation room as their son gave incriminating statements that were used later to convict him of second-degree murder.

Police argued that Alvarado could have left the station. Four justices said that because of his youth, he would not have understood that he could have walked out of the questioning.

Alvarado was sentenced to 15 years to life in prison for his part in a 1995 murder at a shopping mall in Santa Fe Springs, Calif., during an attempted carjacking.

Justice Anthony M. Kennedy, writing for the majority, said the court has never said that age must be considered in determining whether people are in custody and thus entitled to be told their rights.

Charles Hobson, an attorney with the Criminal Justice Legal Foundation, said a ruling the other way would have impeded police investigations. Establishing suspects’ ages, especially immigrant suspects, can be difficult, he said.

“Making a special rule for age would make it more complicated than necessary,” Hobson said. “They would have had to set up a new protocol for juveniles.”

Justice Sandra Day O’Connor agreed with the outcome, but wrote separately to add that age may be a factor in some cases. She noted that Alvarado was 17 1/2, an age at which “many can be expected to behave as adults.”

O’Connor is expected to be a swing vote when the court considers another juvenile case this fall: whether it is constitutional to execute underage killers. States are now allowed to put to death people who were 16 or 17 when they committed crimes.