Polygraph evidence after United States v. Scheffer.

In United States v. Scheffer,(1) the Supreme Court, by an 8-to-1 margin, upheld a Military Rule of Evidence that prohibits reception of polygraph evidence.(2) The defendant challenged the rule on Sixth Amendment and due process grounds when the trial court refused to admit proof of an exculpatory polygraph examination administered by a government examiner at the government's request.(3)

The Court's decision dealt a serious blow to proponents of polygraph evidence. A close examination of the ruling, however, suggests that the Court may be more receptive to the evidence than one might suppose from the margin of the government's victory.

Justice Clarence Thomas wrote the opinion for the Court. The principal opinion is straightforward enough. Due process and the Sixth Amendment's Compulsory Process Clause together establish a constitutional right of criminal defendants to put on exculpatory evidence, but the right to put on a defense is subject to rules of evidence or procedure that are not "arbitrary or disproportionate" in light of legitimate government interests.(4) The military's per se prohibition of polygraph evidence serves several such legitimate interests and so is constitutionally permissible.

Thomas identified three legitimate state interests supporting the per se exclusionary rule. First, because there is reasonable disagreement about the accuracy of the polygraph technique, the exclusionary rule serves a legitimate interest in excluding unreliable evidence.(5) Second, the rule preserves the jury's traditional role as the arbiter of credibility.(6) Third, the rule avoids extensive litigation on motions in limine over the utility of polygraph evidence on a case-by-case basis.(7)

Justice John Paul Stevens, the lone dissenter, challenged each of these interests. Polygraph evidence, the dissenting opinion maintains, is at least as reliable as much of the other evidence that is routinely admitted, even if one accepts the estimates of reliability given by opponents of polygraph evidence.(8) Indeed, the government itself makes extensive use of the polygraph technique.

Admitting polygraph evidence, in Stevens's view, would not displace or disparage the jury. On the contrary, denying jurors evidence because they cannot be trusted with it shows far more disrespect for the jury than would admitting the evidence.(9) As for the burden of litigating admissibility questions, that burden attends the reception of all expert testimony and could be minimized by a rule that set standards for admissibility rather than banning the evidence no matter how the examination was conducted.(10)

Concurring opinion

Justice Anthony Kennedy filed a concurring opinion, joined by Justices Sandra Day O'Connor, Ruth Bader Ginsburg, and Stephen Breyer. Kennedy agreed with the justices joining the Thomas opinion that the political branches of government are constitutionally free to ban polygraph evidence because there is a genuine debate about its reliability.

The concurrence, however, agreed with Stevens's dissent with respect to the role of the jury and the burden of litigating admissibility issues. Moreover, Kennedy frankly expressed "doubt... that the rule of per se exclusion is wise."(11)

Thus, eight justices agree that a per se rule excluding polygraph evidence is a constitutional option for legislatures or state courts to adopt, but five justices believe that this approach is unwise as a matter of policy. The difference is important, for while the federal courts may not, after Scheffer, compel the reception of exculpatory polygraph evidence in state courts on constitutional grounds, the Federal Rules of Evidence do not contain any specific rules about this evidence.

Most of the states now follow some version of the federal rules. Most have, however, by way of judicial decision, adopted a per se bar to the introduction of polygraph evidence.(12)

Thus, in both civil and criminal litigation, in both state and federal court, the admissibility of polygraph evidence depends on the interpretation given to the rules of evidence governing expert testimony. If Edward Scheffer had been prosecuted in federal district court, the judge, following the Supreme Court's Daubert(13) decision, could easily have come to the conclusion that the polygraph evidence was admissible.(14)

If the government appealed such a ruling and the case came to the Supreme Court, it seems likely that the four justices joining the Thomas opinion would conclude that, as a matter of law, polygraph evidence is not based on valid science and would not be helpful to the jury, and so should be excluded under Daubert.

But five justices accept the possibility that at least in some cases the evidence could satisfy the Daubert standard for admissibility. Indeed, if Kennedy's skepticism about the per se exclusionary rule is taken seriously, there would seem to be five justices willing to agree that there are cases in which polygraph evidence ought to be admitted under Daubert.

Motions to suppress

In at least one context, the reasoning of the Scheffer case is irrelevant. When criminal courts rule on motions to suppress evidence on account of unconstitutional police action, the underlying constitutional right may imply special constitutional rules of evidence, such as the rule that a defendant's testimony at a suppression hearing may not be used against him or her at a subsequent trial.(15)

Moreover, suppression motions are heard by the court sitting without a jury. Thus, the admissibility of polygraph evidence at a suppression hearing is a question not properly subject to deference to legislative evaluation of polygraph reliability. Nor is it a question in which the jury plays the role of assessing credibility. The Fifth Circuit's recent decision setting aside the per se exclusionary rule in the suppression hearing context(16) should therefore emerge unscathed by the Supreme Court's ruling in Scheffer.

Nonetheless, the Scheffer decision is an exasperating one. Courts routinely receive eyewitness testimony, lay opinion testimony about the speed of automobiles or the emotional state of other people, social framework evidence, hypnotically enhanced testimony, handwriting analysis, and other evidence of distinctly doubtful reliability.

Polygraph evidence is as reliable as many other types of evidence, as the government's widespread use of the technique in both the national security and the criminal investigation contexts suggests. This evidence could hardly be worse than jury evaluation of witness demeanor, celebrated by Thomas but belied by a great mass of empirical evidence.(17)

One wonders what the officers on Scheffer's jury would say if told that they had been denied access to the exculpatory polygraph examination. The Court, in the name of the jury, basically delivered Jack Nicholson's message from A Few Good Men: "You can't handle the truth."

Scheffer also raises the unattractive prospect of resurrecting the Frye(18) test in the context of right-to-put-on-a-defense claims. Eight justices agree that reasonable disagreement about the reliability of scientific evidence suffices to insulate an exclusionary rule from constitutional attack by the criminal defendant.

Thus, to overcome a State rule banning, say, proof of post-traumatic stress disorder or voiceprint evidence, the criminal defendant must show general acceptance of the scientific technique in dispute. That is precisely the inquiry that was rejected as too restrictive and too indeterminate in Daubert; it may now reenter the law through the back door.

That is not likely to happen. Although resurrecting Frye in constitutional cases follows logically from the Scheffer case, Scheffer clearly treats polygraph evidence as sui generis. Indeed, the Scheffer opinions all accept the continuing authority of Rock v. Arkansas,(19) in which the Court struck down a state's per se rule barring hypnotically enhanced testimony.

There never has been a consensus on the reliability of this evidence. If Rock is still good law, the reliability of evidence for due process purposes is a question of federal constitutional law, rather than of state or congressional discretion.

The reaffirmation of Rock v. Arkansas makes the peculiarity of polygraph evidence pretty obvious. It seems unlikely that an opinion of an expert about credibility based on a polygraph examination is less reliable than the testimony of a witness whose recollection has been "enhanced" by hypnotism.

The justices clearly see something somehow unique, and somehow sinister, about polygraph evidence. If that is indeed the case, then, for purposes of future claims of constitutional right to introduce exculpatory evidence, the fewer generalizations drawn from a case about polygraph evidence, the better.

Notes

(1.) 118 S. Ct. 1261 (1998).

(2.) See MIL. R. EVID. 707.

(3.) The Court of Military Appeals had struck down the rule. See United States v. Scheffer, 44 M.J. 442 (C.A.A.F. 1996), rev'd, 118 S. Ct. 1261 (1998).

(4.) See Scheffer, 118 S. Ct. 1261, 1264-65.

(5.) Id. at 1266.

(6.) Id. at 1266-67.

(7.) Id. at 1267.

(8.) Id. at 1276 (Stevens, J., dissenting) ("even the studies cited by the critics place polygraph accuracy at 70 percent") (footnote omitted).

(9.) Id. at 1278 (Stevens, J., dissenting) ("As with the reliance on the potential unreliability of this type of evidence, the reliance on a fear the average jury is not able to assess the weight of this testimony reflects a distressing lack of confidence in the intelligence of the average American.") (footnote omitted).

(10.) See id. at 1278-79 (Stevens, J., dissenting).

(11.) Id. at 1269 (Kennedy, J., concurring).

(12.) See id. at 1266.

(13.) Daubert v. Merrell Dow Pharm., Inc., 509 U.S. 579 (1993).

(14.) Some federal courts have reached the conclusion that polygraph evidence passes the Daubert test, while others have rejected these claims. Compare United States v. Crumby, 895 F. Supp. 1354 (D. Ariz. 1995), with United States v. Black, 831 F. Supp. 120 (E.D.N.Y. 1993). On the emerging trend toward a warmer judicial reception for polygraph evidence, see James R. McCall, Misconceptions and Reevaluation--Polygraph Admissibility After Rock and Daubert, 1996 ILL. L. REV. 363.

(15.) See United States v. Salvucci, 448 U.S. 83 (1980); Simmons v. United States, 390 U.S. 377 (1968).

(16.) United States v. Posado, 57 F.3d 428 (5th Cir. 1995).

(17.) See Olin Guy Wellborn III, Demeanor, 76 CORNELL L. REV. 1075, 1075 (1991) ("According to the empirical evidence, ordinary people cannot make effective use of demeanor in deciding whether to believe a witness. On the contrary, there is some evidence that the observation of demeanor diminishes rather than enhances the accuracy of credibility judgments.")

(18.) Frye v. United States, 293 F. 1013 (D.C. Cir. 1923), superseded by statute as stated in Daubert, 509 U.S. 579.

(19.) 483 U.S. 44 (1987).

Donald A. Dripps is a professor at the University of Illinois College of Law.