The second case tests whether police and prosecutors may use physical evidence, such as a gun or drugs, despite a Miranda violation.
The violation in the case of Samuel Patane is minor at best, legal experts say. Patane had been arrested for threatening a former girlfriend in Colorado Springs, Colo., and was ordered not to contact her. Shortly after he was released, Patane began calling his former girlfriend.
A police officer and federal agent went to Patane's apartment and handcuffed him. When they began to give Patane his Miranda rights, he cut them off in mid-sentence. When the officer asked about his gun, Patane said, "The Glock is in my bedroom on a shelf." He was indicted for being a felon in possession of a gun. However, a federal judge held that the officers violated the Miranda rules because they did not fully warn him of his rights and obtain a waiver before questioning him. Based on this conclusion, the U.S. Court of Appeals in Denver said the physical evidence against him -- the Glock pistol -- should have been thrown out.
In U.S. vs. Patane, the government's lawyers are urging the court to rule that physical evidence may be used against suspects, even when their Miranda rights are violated.
Under the so-called "fruit of the poisonous tree" doctrine, the government cannot use evidence that was obtained after violating a suspect's constitutional rights. If police without a search warrant break into a suspect's house, the usual rule is that any evidence found may not be used against the suspect.
It is not clear whether the rule applies to Miranda violations. Olson said the court should rule that the Miranda decision prevents only a suspect's "unwarned statements" from being used in court. Lawyers for the American Civil Liberties Union say a broader rule is needed to deter police misconduct.
In the third case, police in Lincoln, Neb., went to arrest and question John Fellers after he was indicted on charges of drug dealing. Without giving Fellers Miranda warnings or consulting his lawyer, the officers asked him about the people named in the indictment. Fellers said he had used drugs with them.
In the mid-1960s the high court had said police could not question an indicted defendant without speaking to his or her lawyer. But in Fellers vs. United States, the government's lawyers say voluntary statements to the police should not be suppressed.
Criminal law experts say it is hard to forecast the outcome because the current justices have dealt little with the practical aspects of police questioning.
Some predict the court will make it easier, not harder, to make use of voluntary confessions by criminals.
The justices "want to limit the damage of having guilty criminals going free because of technical mistakes by the police," said Kent Scheidegger of the Criminal Justice Legal Foundation in Sacramento. He said it was unlikely Miranda would be repealed.
"That's overblown," Scheidegger said. "If [the justices] had wanted to get rid of Miranda, they would have done it three years ago."