There’s probably no better example of the “he said/she said” case than one of date rape.  There are no witnesses, at least direct ones, and forensics aren’t much help, since the defendant admits that sex occurred.  Wouldn’t it be nice to be able to reliably determine who was telling the truth? 

Sahil Sharma found himself on the short end of that problem last year; he was indicted for raping a young girl he’d gone out to dinner with.  Shortly after the indictment, his lawyer approached the Summit County Prosecutor’s office and suggested the case be resolved by having Sharma submit to a polygraph exam.  The prosecutor’s office initally consented, but backed off when the victim refused to agree to it.  The defense lawyer went ahead and got not one, but three different polygraph tests, all indicating that the defendant was being truthful in his responses to critical questions concerning the case, some of them initially suggested by the state before it withdrew its consent to a stipulation.

As anybody familiar with this subject knows, the seminal case on polygraph evidence is the 1978 Ohio Supreme Court decision in State v. Souel, where the Court held that a polygraph result could be admitted only by the stipulation of both parties, and with certain other procedural safeguards in place.  There’s not much beyond that; the last Supreme Court decision was in 1991, when the Court declined to extend Souel by requiring that the state produce the polygraph results of three state witnesses in discovery.  The stipulation requirement would seem to have doomed Sharma’s efforts, but his attorney did a nice job in seizing on certain language in Souel to back up his claim that a fresh look at the admissibility of polygraph evidence was needed.  He put together a very nice brief on the subject, which you can find on the court’s website here.  (NOTE:  See Update, below)

And, after conducting an extensive evidentiary hearing, Judge Hunter bought it.  She agreed that Souel had left room for improvement in polygraph techniques, that both Souel and Davis were decided before the new Rules of Evidence on expert witnesses, as well as major developments in the law pertaining to that subject, and that the tests should be admitted.  (Her opinion can be found here.)  She imposed some requirements, the major one being that the defendant had to testify at trial before the experts did.

Hunter’s decision is a gutsy one, but it’s not clear that it will have much impact.  The state tried to appeal her ruling, but the appellate court bounced it as premature.  The defendant wound up waiving a jury and trying it to the bench, resulting in an acquittal.  The state could appeal the ruling (although not the result), but it’s not clear that the court of appeals would even reach that issue.  As it turns out, none of the polygraph experts testified, and Hunter based her verdict on inconsistencies in the victim’s story.  Needless to say, Hunter’s decision on its own has no precedential weight.

What’s more, even she acknowledged that her decision to allow the polygraph results was based on the “unique circumstances” of the case:  the defense attorney did an excellent job, not only in the briefwork, but in selecting the experts and preparing their testimony.

And an argument can certainly be made that Hunter’s decision is wrong.  The reason for the exclusion of polygraph testimony is not because it’s not reliable enough, but because of fears that jurors will think it’s too reliable.  A polygraph expert isn’t like an expert on ballistics or DNA or fingerprints.  Their job is to testify about ballistics or DNA or fingerprints, while the polygraph expert’s job is to testify that someone is or isn’t telling the truth, and that’s a determination that’s been historically and universally regarded as the function of the jury.  You can give all the instructions about weight of the evidence and not infringing on the jury’s function you want, and at the end of the trial it’s going to be damned hard for a juror to conclude that a witness is lying if there’s an expert who said specifically that he wasn’t.

The other problem is that this is a two-edged sword.  If the defense is allowed to introduce polygraph results to shore up the defendant’s credibility, why can’t the prosecution introduce them to buttress the credibility of the victim, or of a key witness?

The dirty little secret — except it’s not so secret — is that law enforcement relies extensively on the polygraph.  As Hunter’s opinion points out, the Summit County prosecutor’s office had dismissed two major sex offense cases within the previous year on the basis of polygraph tests.  All in all, though, maybe that’s the way it should stay.  Putting the polygraph in the courtroom could wind up being a classic example of the Law of Unintended Consequences.

UPDATE:  I’ve reset the links to the brief and opinion about 5 times, but the Summit County website keeps changing them.  Go to the docket of the case here.  The Brief was the document filed on 3/26/07, and the Court’s order was made on 5/11/07.  Download the documents for that day.