Concluding that lie-detector tests cannot always be trusted to tell the truth, the Supreme Court ruled Tuesday that no one has a right to use one to defend himself in court.
The 8-1 decision upholds a rule that bars the use of polygraphs in military courts-martial. By implication, it also upholds the rule in most state courts that exclude the use of polygraphs.
“There is simply no consensus that polygraph evidence is reliable,” wrote Justice Clarence Thomas. “To this day, the scientific community remains extremely polarized about the reliability of polygraph evidence.”
The ruling came in the case of Edward G. Scheffer, an airman who had been stationed in 1992 at March Air Force Base near Riverside, Calif. He had been accused of writing bad checks and ingesting illegal drugs. He denied the drug charge, and a polygraph analyst found “no deception” in his answers.
Scheffer was prevented from introducing that result in his court-martial under a military rule of evidence and was convicted. The U.S. Court of Appeals for the Armed Forces concluded that he was denied his right to present a defense.
Overturning that result in the case (U.S. vs. Scheffer), the justices said the military’s policy was reasonable and violated no constitutional right. Justice John Paul Stevens dissented.
In a separate case arising from the political firestorm over government support of the arts, the justices heard lively arguments about a 1990 law that requires the National Endowment for the Arts to consider “general standards of decency” in awarding grants to artists. The court is to decide by July whether the decency standard unconstitutionally impairs free expression.
The court’s lie-detector ruling came 100 years after the first crude lie-detection device was invented, and 75 years after judicial hostility toward polygraph evidence first became rooted in precedent.
New Mexico is the only state that permits polygraph evidence to be admitted over an objection. But five of the 11 U.S. circuit courts recently retreated from their absolute bans on polygraph evidence and left the matter up to trial judges.
Still, the Supreme Court refused to open the door any wider.