Foreign nationals arrested in the United States have a right to consult with diplomatic personnel from their home countries, but failure of the US to allow such consultation does not warrant the exclusion of any incriminating statements from their trial.
In a 6-to-3 decision announced Wednesday, the US Supreme Court ruled that an international treaty calling for consulate access to arrestees does not authorize the broad use of the so-called exclusionary rule.
Instead, alleged violations of an international treaty must be dealt with via remedies available under state and federal laws, the court said.
"Under our domestic law, the exclusionary rule is not a remedy we apply lightly," writes Chief Justice John Roberts for the majority.
The ruling comes in two consolidated cases involving a Mexican national and a Honduran national. Both men were convicted of serious crimes in the US, and both were never told that they had a right to meet with consular officials after their arrest.
Lawyers for the men argued that the Vienna Convention on Consular Relations empowered their clients to seek a remedy in American courts.
In one case, lawyers suggested that the appropriate remedy would be to bar all statements their client had made to police from use as evidence at his trial.
The Supreme Court disagreed, saying such a remedy would be "vastly disproportionate" to the alleged treaty violation. Chief Justice Roberts said there was nothing in Article 36 of the Vienna Convention authorizing exclusion of evidence as a remedy for a treaty violation.
"If we were to require suppression for Article 36 violations without some authority in the convention, we would in effect be supplementing those terms by enlarging the obligations of the United States under the convention," Roberts writes. "This is entirely inconsistent with the judicial function."
Roberts adds, "Courts must apply the remedy as a requirement of federal law. But where a treaty does not provide a particular remedy ... it is not for the federal courts to impose one on the states through lawmaking of their own."
In a dissent, Justice Stephen Breyer said the majority was wrong to rule out suppression of evidence as a possible remedy to treaty violations. He said that sometimes such a remedy might be the best approach.
"I would hold that whether the convention requires a state court to suppress a confession obtained after an Article 36 violation depends on whether suppression is the only remedy available that will effectively cure the related prejudice," he writes.
Justice Breyer says the majority's approach "leaves states free to deny effective relief for convention violations."
He adds, "That approach risks weakening respect abroad for the rights of foreign nationals.... And it increases the difficulties faced by the United States and other nations who would, through binding treaties, strengthen the role that law can play in assuring all citizens, including American citizens, fair treatment throughout the world."
In an apparent response, Roberts writes: "Our holding in no way disparages the importance of the Vienna Convention.... It is no slight to the convention to deny petitioner's claims under the same principles we would apply to an act of Congress, or to the Constitution itself."
In addition to the substance of the court's holding, the opinion offers important insight into an ongoing debate among the justices over the relevance of international law and foreign judicial decisions to American jurisprudence.
The majority justices did not reach the most significant issue raised in the case – whether the treaty grants enforcement rights to individuals in addition to the signatory nations.
Four dissenting justices, Breyer, John Paul Stevens, David Souter, and Ruth Bader Ginsburg have stated their view that the treaty grants individually enforceable rights.
But Roberts dodged the issue in his majority opinion, saying that the court would assume, without deciding, that such rights were granted. That leaves the questions open for another day.
Under the Constitution's supremacy clause, treaties ratified by the Senate carry the force of US law. But what happens when an international organization issues rulings interpreting (and in some cases redefining) American treaty obligations? To what extent must US courts abide by such rulings?
Article 36 of the Vienna Convention on Consular Relations establishes two requirements for countries that arrest or detain a foreign national. First, the arrestee is to be informed without delay that he or she has a right to meet with consular officials. Second, the consulate is to be notified of the arrest if the arrestee requests such notification.
The requirements are clear. But what is less clear is what happens if the detaining nation does not comply with the requirements.
The International Court of Justice has ruled that the treaty empowers individual arrestees to sue the detaining country in its own courts. But other courts have rejected that view, ruling that the treaty must be enforced nation to nation.
Of the two consolidated cases under consideration by the Supreme Court, one involved Moises Sanchez-Llamas, a Mexican national, who was convicted in Oregon of shooting a police officer. He was sentenced to 20 years in prison.
On appeal, he argued that even though he had been warned by police that he had a right to remain silent and to consult a lawyer, he was never advised of his right to consult with Mexican consular officials before police questioned him. He said incriminating statements he made to police should be suppressed because they were obtained in violation of the Vienna Convention.
The Oregon Supreme Court rejected the argument and affirmed Mr. Sanchez-Llamas's conviction.
The second case involved the trial of Mario Bustillo, a Honduran national convicted in Virginia of killing a man by striking him with a baseball bat. He was sentenced to 30 years in prison. Mr. Bustillo said police had the wrong man, that an individual nicknamed "Sirena" was the killer. Bustillo's lawyers obtained a secretly recorded videotape of Sirena admitting the killing.
The lawyers also argued that their client should receive a new trial because the US had failed to notify Bustillo of his right to consult with Honduran consular officials. Honduran officials said that had they known about the case earlier, they could have helped Bustillo locate and identify Sirena, who fled to Honduras the day after the victim in the case died, according to court records.
The Virginia Supreme Court denied Bustillo's appeal, saying it had not been filed in the required amount of time.
In its ruling Wednesday, the Supreme Court upheld the rulings of both the Oregon and Virginia courts.