WASHINGTON -- The U.S. Supreme Court is set to hear a case today that could provide a glimpse of the justices' thinking about when interrogations by law enforcement officials become abusive.

The court's ruling could be highly significant as the government is seeking intelligence about al-Qaida and other terrorist groups and is placing some terrorism suspects on a separate legal track that leaves them without traditional protections.

It would apply to U.S. citizens under questioning but not foreigners such as those being held at Guantanamo Bay, Cuba.

Civil libertarians are indignant over the government's use of "enemy combatant" status to jail and question some U.S. citizens without giving them access to a lawyer or the outside world. Just what those interrogations are like is unknown.

At issue before the nation's high court is whether a suspect's constitutional rights are violated if police question him aggressively without reading him his rights but his answers are never used against him in a criminal proceeding.

"There are certainly parallels" to counterterrorism interrogations, said David Rudovsky, a University of Pennsylvania Law School professor who is an expert in police procedures.

"Some of the justices will have to be wondering, 'If I rule against the police here, will that hamper the government in the war against terrorism?'"

The case involves Oliverio Martinez, an Oxnard, Calif., farm worker who was heading home on his bicycle in November 1997 when he came upon police investigating drug activity.

Police ordered Martinez off his bike and discovered he had a knife. A struggle ensued, during which Martinez seized the gun of one of the officers, police say. Another police officer shot Martinez five times.

Oxnard police patrol supervisor Sgt. Ben Chavez arrived on the scene shortly after the shooting and accompanied Martinez to the hospital, quizzing him in the ambulance and in the emergency room about what had happened and tape-recording the interrogation.

Martinez lapsed in and out of consciousness during the 45-minute interview, complained that he was in pain and said he feared he was about to die.

Martinez twice told Chavez he didn't want to talk. But Chavez persisted, even when medical staff told him to leave the trauma room. Chavez left, but returned and continued to tape his interview. Chavez never read Martinez the Miranda warning advising him that he had the right to remain silent and to speak to an attorney.

Martinez -- who was left blind and paralyzed -- was never charged with a crime. Now 34, he sued Chavez under the Civil Rights Act, saying the "coercive" interrogation violated his constitutional rights. Chavez countered that as a public official he was immune to such lawsuits.

The U.S. District Court for Central California, and later the 9th U.S. Circuit Court of Appeals, disagreed.

The appeals court held that Martinez's Fifth Amendment right against self-incrimination and his 14th Amendment right to due process had been violated. The court ruled that Chavez was liable, even as a public official, because his conduct violated "clearly established" constitutional rights.

In a brief filed with the Supreme Court, Chavez maintained that Martinez's words were never used against him in court, so his rights could not have been violated.

"Persistent questioning of a seemingly dying witness may make judges [and many other people] squeamish but that is not a constitutional violation," Chavez's court petition said.

Chavez claimed he thought Martinez might die and was trying to get his "dying declaration" about what had happened, not to build a case against him.

Martinez's court filing said the interrogation "violated values at the core of constitutional constraints on abusive government conduct."

"Self-incrimination and due process rights are not limited to when a statement is introduced at criminal trial," it said.

The Supreme Court in 2000 reaffirmed the Miranda decision, which said police must inform suspects of their rights.

The question posed in Chavez vs. Martinez is whether the Miranda decision guarantees the right to silence or, more narrowly, the right against the judicial admission of incriminating testimony.