United States v. Scheffer, 523 U.S. 303

Supreme Court case upholding military polygraph evidence ban but not creating a constitutional prohibition on polygraph evidence.

Legal analysis, policy review, or empirical study examining the intersection of polygraph testing with legal systems and public policy.

In Scheffer, the Supreme Court upheld the military's per se ban on polygraph evidence but importantly did not create a blanket constitutional prohibition. Justice Stevens' dissent noted that polygraph may be more reliable than some currently admitted evidence types. The narrow holding left civilian courts free to make their own admissibility determinations.

Scheffer is often misread as a blanket prohibition; in fact, it only upholds the military rule and leaves civilian admissibility questions open.

Background & Context

United States v. Scheffer, decided in 1998, marked the first time the Supreme Court issued a ruling on the admissibility of polygraph evidence. The case emerged from the military justice system, where debates over polygraph reliability had been particularly intense. The central legal question was whether Military Rule of Evidence 707, which makes polygraph evidence inadmissible in court-martial proceedings, unconstitutionally abridged the right of accused members of the military to present a defense.

This case arrived at a pivotal moment for polygraph testing in American jurisprudence. Polygraph machines were increasingly being used outside the courtroom, with prosecutors using results to extract confessions and defense lawyers using them for leverage in plea bargains. The Supreme Court's ruling would therefore have implications far beyond the military context, potentially influencing how civilian courts across the nation approached polygraph evidence admissibility.

The constitutional stakes were substantial. The lower appellate court had held that a per se exclusion of polygraph evidence offered by an accused to rebut an attack on his credibility violated his Sixth Amendment right to present a defense. The Supreme Court's review would determine whether blanket exclusionary rules for polygraph evidence could survive constitutional scrutiny.

Research Design & Methodology

In March 1992, respondent Edward Scheffer, an airman stationed at March Air Force Base in California, volunteered to work as an informant on drug investigations for the Air Force Office of Special Investigations (OSI). His OSI supervisors advised him that during his undercover work, they would ask him to submit to drug testing and polygraph examinations.

In early April, one of the OSI agents supervising respondent requested that he submit to a urine test. Shortly after providing the urine sample, but before the results were known, respondent agreed to take a polygraph test administered by an OSI examiner. In the opinion of the examiner, the test indicated no deception when respondent denied using drugs since joining the Air Force. However, urinalysis revealed the presence of methamphetamine, and respondent was tried by general court-martial for using that drug and for other offenses.

Respondent was tried by general court-martial on charges of using methamphetamine, failing to go to his appointed place of duty, wrongfully absenting himself from the base, and uttering insufficient funds checks. He testified at trial on his own behalf, relying upon an innocent ingestion theory and denying that he had knowingly used drugs while working for OSI. On cross-examination, the prosecution attempted to impeach respondent with inconsistencies between his trial testimony and earlier statements he had made to OSI. Respondent sought to introduce the polygraph evidence in support of his testimony that he did not knowingly use drugs. The military judge denied this motion based on Military Rule of Evidence 707.

The legal analysis proceeded through multiple levels of military appellate review:

• Scheffer was convicted on all counts and sentenced to a bad-conduct discharge, confinement for 30 months, total forfeiture of all pay and allowances, and reduction to the lowest enlisted grade. The Air Force Court of Criminal Appeals affirmed
• By a 3-to-2 vote, the United States Court of Appeals for the Armed Forces reversed (44 M.J. 442 (1996))
• The U.S. Supreme Court granted certiorari to resolve the constitutional question

Results & Key Findings

The Supreme Court reversed the Court of Appeals for the Armed Forces, holding 8-1 that Military Rule of Evidence 707 does not unconstitutionally abridge the right to present a defense. The Court held that Rule 707 does not violate constitutional principles.

The majority opinion, delivered by Justice Thomas, established several key holdings:

• A defendant's right to present relevant evidence is subject to reasonable restrictions to accommodate other legitimate interests in the criminal trial process. State and federal rulemakers therefore have broad latitude under the Constitution to establish rules excluding evidence
• There is simply no consensus that polygraph evidence is reliable. The scientific community remains extremely polarized about the reliability of polygraph techniques
• The approach taken by the President in adopting Rule 707 is a rational and proportional means of advancing the legitimate interest in barring unreliable evidence. Although the degree of reliability may depend upon various factors, there is simply no way to know in a particular case whether a polygraph examiner's conclusion is accurate. Individual jurisdictions may reasonably reach differing conclusions as to whether polygraph evidence should be admitted
• Rule 707 does not implicate any significant interest of the accused. The court members heard all the relevant details from the accused, and the Rule did not preclude him from introducing any factual evidence—respondent was barred merely from introducing expert opinion testimony to bolster his own credibility. Moreover, Rule 707 did not prohibit respondent from testifying on his own behalf

Justice Kennedy's Concurrence: Kennedy expressed doubt about whether the per se exclusion rule was wise, noting tension between the ruling and the Daubert standard for scientific evidence, and highlighting inconsistency between the Government's extensive use of polygraphs to make vital security determinations and its argument stressing the inaccuracy of these tests.

Justice Stevens' Dissent: Stevens argued that the Government's concerns were plainly insufficient to support a categorical rule that prohibits the admission of polygraph evidence in all cases, no matter how reliable or probative the evidence may be. He noted that there is no question that in recent years polygraph testing has gained increasingly widespread acceptance as a useful and reliable scientific tool.

Discussion & Significance

The Scheffer decision's significance extends far beyond its immediate military context. The ruling is frequently misunderstood as creating a blanket constitutional prohibition on polygraph evidence, but the Court's holding was deliberately narrow. The Court emphasized that individual jurisdictions may reasonably reach differing conclusions as to whether polygraph evidence should be admitted, leaving civilian courts free to develop their own approaches.

The decision reflects deep judicial skepticism about polygraph reliability while acknowledging ongoing scientific debate. The Court noted that although some Federal Courts of Appeal have abandoned the per se rule excluding polygraph evidence, leaving its admission to district court discretion under Daubert, at least one Federal Circuit has reaffirmed its per se ban, and most States maintain per se rules excluding polygraph evidence. This fragmented landscape underscores the lack of consensus that the majority found dispositive.

A critical aspect of the Court's reasoning involved balancing evidentiary reliability concerns against constitutional rights. The Court affirmed that State and Federal Governments have a legitimate interest in ensuring reliable evidence is presented to the trier of fact, and that the exclusion of unreliable evidence is a principal objective of many evidentiary rules. This principle allowed the Court to uphold Rule 707 without finding a constitutional violation.

Limitations & Considerations

The decision's scope is significantly more limited than commonly understood. The Court ruled only on the constitutionality of a military evidentiary rule, not on the scientific validity of polygraph testing or whether civilian courts must adopt similar exclusionary rules. The Court noted there is simply no consensus that polygraph evidence is reliable, and various courts may reasonably reach differing conclusions, explicitly preserving judicial discretion in non-military contexts.

The fractured nature of the opinion reveals internal Court divisions. Justice Thomas announced the judgment and delivered the opinion with respect to certain parts joined by different configurations of justices. Justice Kennedy filed an opinion concurring in part and concurring in the judgment, and Justice Stevens filed a solo dissent. This fragmentation suggests that even among the justices voting to uphold Rule 707, there was substantial disagreement about the reasoning and broader implications.

The tension between the government's operational reliance on polygraphs and its legal arguments against admissibility remains unresolved. Justice Kennedy noted the inconsistency between the Government's extensive use of polygraphs to make vital security determinations and the argument it made stressing the inaccuracy of these tests, a contradiction that continues to generate debate about polygraph validity.

Practical Applications

For polygraph examiners and military legal practitioners, Scheffer definitively establishes that Military Rule of Evidence 707 remains constitutional and enforceable. No polygraph evidence—whether inculpatory or exculpatory—can be admitted in court-martial proceedings under this blanket exclusionary rule. Defense counsel in military cases cannot invoke the Sixth Amendment to override this evidentiary prohibition.

For civilian jurisdictions, however, Scheffer provides guidance rather than mandate. State and federal courts retain discretion to admit or exclude polygraph evidence based on their own evidentiary standards, reliability determinations, and policy considerations. The decision supports but does not require exclusionary approaches. Courts inclined to admit polygraph evidence under appropriate foundational showings can distinguish Scheffer as limited to the military context, while courts favoring exclusion can cite Scheffer's concerns about scientific reliability and jury confusion. The result is a continued patchwork of admissibility standards across American jurisdictions, with Scheffer serving as an influential but not controlling precedent in civilian criminal proceedings.