The Supreme Court agreed yesterday to decide whether to narrow the scope of "interrogation" covered by the so-called Miranda rules, which are intended to implement the constitutional protection against self-incrimination.

The court acted in a Rhode Island murder case hinging on what police officers may say in the presence of a suspect who doesn't have a lawyer.

The case began in January 1975, when Providence taxi driver John Mulvaney was kidnaped, robbed, and murdered with a shotgun blast to the back of the head. His body was found four days later in a shallow grave.

Police arrested Thomas J. Innis, who had phoned for the cab and had made statements to witnesses implicating himself.

The arresting officer advised Innis of his right to be silent under the high court's 1966 Miranda decision and to have the advice of counsel. Miranda warnings also were given by a sergeant who arrived at the scene shortly afterwards. When the warnings were given a third time, by Police Capt. John J. Leyden, Innis said he wanted to see an attorney.

Leyden assigned three patrolmen to drive Innis to headquarters in a police cruiser. He ordered them not to question or coerce Innis in any way.

En route to headquarters at about 4:30 a.m., two of the officers had a conversation, heard in full by Innis.This raises the key issue in the case: whether the police car conversation, even if indirect, was an impermissible "interrogation."

Recalling the episode at Innis' trial, Officer Joseph Gleckman said that in "talking back and forth," he told Officer Richard McKenna that "I frequent this area while on patrol and there's a lot of handicapped children running around [because of a school for them].... God forbid one of them might find a weapon with shells and they might hurt themselves."

On hearing this, Innis expressed fear that such just a tragedy might occur and asked to be returned to the scene of his arrest so that he could show the policemen where the shotgun was hidden. There, Innis led the officers to the shotgun and some shells.

At the trial, the prosecution introduced the shotgun as evidence, over defense objection, and used it to help obtain a conviction. Innis received a life sentence for murder, 20 years for kidnaping and 30 years for robbery to be served concurrently.

Last August, a divided Rhode Island Supreme Court reversed. "Police officers... must not be permitted to achieve indirectly, by talking with one another, a result which the [U.S.] Supreme Court has said they may not achieve directly by talking to a suspect who has been ordered not to respond," the majority opinion said. "The same 'subtle compulsion' exists."

The majority also rejected the trial judge's contention that Innis had made an "intelligent waiver" of his right to remain silent. The court said that the shotgun was inadmissible as evidence because its seizure was "the product of the improper remarks of Officer Gleckman," and contended that Gleckman's remarks were not innocent.

The dissenters said that the Constitution does not require policemen in the company of a suspect "to assume the role of contemplative monks." They found nothing to support the notion that Gleckman had "deliberately set out to elicit incriminating remarks."