"There is simply no consensus that polygraph evidence is reliable," the court said, ruling 8 to 1 in the case of a California airman who wanted to tell a court-martial jury that he passed a lie-detector test.
Various courts "may reasonably reach differing conclusions as to whether polygraph evidence should be admitted," Justice Clarence Thomas wrote for the court.
"To this day, the scientific community remains extremely polarized about the reliability of polygraph techniques," Thomas wrote. "There is simply no way to know in a particular case whether a polygraph examiner's conclusion is accurate."
The military ban on use of such evidence "does not unconstitutionally abridge the right to present a defense," Thomas added.
Tuesday's ruling reverses a military appeals court's decision that said an airman should not have been automatically barred from introducing lie-detector results during his court-martial on charges of using drugs and writing bad checks.
A military rule signed by President Bush in 1991 forbade any reference to lie-detector tests in criminal trials.
But the U.S. Court of Appeals for the Armed Forces said that rule violated Edward G. Scheffer's right under the Constitution's Sixth Amendment to present relevant evidence in his defense. The military appeals court said Scheffer should be given a chance to convince a judge that the test results should be allowed.
When the Supreme Court heard arguments last November, some justices questioned whether letting defendants who pass polygraph tests seek to use the results in court could open the door to prosecutors seeking to present failing test results as evidence of someone's guilt.
In saying the military rule does not violate the Constitution, the Supreme Court noted that most state courts ban polygraph evidence. Some federal courts have recently dropped a ban on such evidence, leaving the decision to trial judges, Thomas noted.
His opinion was joined in full by Chief Justice William H. Rehnquist, and Justices Antonin Scalia and David H. Souter.
Joining in part were Justices Anthony M. Kennedy, Sandra Day O'Connor, Ruth Bader Ginsburg and Stephen G. Breyer.
Writing for the four, Kennedy agreed the military rule did not violate the Constitution. "I doubt, though, that the rule of. . .exclusion is wise," Kennedy said, adding that a future case might present a more compelling reason for allowing such testimony to be introduced.
Justice John Paul Stevens dissented, saying the ruling "rests on a serious undervaluation of the importance of the citizen's constitutional right to present a defense to a criminal charge."
By Laurie Asseo ©1998 The Associated Press. All Rights Reserved. This material may not be published, broadcast, rewritten, or redistributed