By Stephen Young
By Stephen Young
By Stephen Young
By Jim Schutze
By Rachel Watts
By Lauren Drewes Daniels
In 1993, the U.S. Supreme Court concluded that the test for polygraph testimony is governed by the rules for all scientific evidence--that it must be both credible and relevant.
Today, 26 states have allowed polygraph exams into evidence in some form--either when both sides agree to allow it, or only in front of a judge, or for appeals purposes. But in Texas, thus far no polygraph examiner has convinced a judge that lie detectors are reliable enough to allow him to testify in front of a jury.
As far as prosecutor Norm Kinne is concerned, that's as it should be. While he believes polygraph examiners provide a useful tool in the investigative process, he doesn't think they have any place in a jury trial.
"I know the examiners are going to jump up and down and get mad at me, but I think it's still an art, not a science," he says. "If the testing were truly scientific, different examiners should be able to obtain the same result when testing a defendant. But we have cases where someone fails one exam and passes another."
He points to the high-profile case of Walker Railey, the infamous Methodist minister who was acquitted by a jury in 1993 in the attack on his wife that left her severely brain damaged. According to Kinne, Railey took three different polygraphs; he passed one and failed another, and the third was inconclusive.
"Doesn't sound real scientific to me," Kinne says.
Holden says he is aware of the Railey polygraphs and says there is a professional explanation for every one of those test results, but he refuses to discuss them in detail. He will only say, "Someone said he passed or failed, but that is not necessarily what the data really show."
Such equivocating is precisely what Kinne sees as the problem with considering polygraph examinations a science. "To me, a layman, science means you get the same results no matter who is giving the test. For example, either you have a 0.10 blood alcohol level or you don't, and it doesn't matter who's administering the test."
What Kinne fears most is the inevitable prospect of "courtroom swearing matches between polygraph examiners" if they were allowed to testify.
"How is that different from disagreements between two psychologists or two handwriting analysts?" Holden retorts. He claims studies show that polygraph exams are far more reliable than eyewitness testimony, which is used all the time--frequently with dire results. "Just ask Ricky Dale Thomas," Holden says. "The state trooper believed in his heart that Thomas was the man he stopped on the highway that night."
It is interesting to note that local prosecutors have no qualms about using the expert testimony of psychiatrists who are quick to label defendants sociopaths and to predict their future dangerousness with a degree of certainty the psychiatric profession says is impossible and unethical.
Lawyers need to learn how to cross-examine polygraph examiners, Holden says. Once they do, they'll be able to expose faulty tests, and juries will be able to determine which expert's work is most believable.
The debate that rages in legal circles is not fueled by questions about the reliability of polygraphs, defense attorneys say, but by prosecutors' and jurists' fear of the impact polygraph testimony may have in the courtroom.
It's one thing if experts disagree about peripheral issues concerning evidence--a defendant's state of mind, handwriting, etc.--but polygraph examiners are dealing with the absolute heart of a case: Did the defendant commit the offense?
"The argument is that the jury is supposed to judge a defendant's believability, and introducing the results of a lie-detector test substitutes a machine for the intuition of the jury," attorney Troy says. "The fear is that they'll be unreasonably swayed by this expert testimony, in part because it will take the burden of deciding guilt or innocence off of them."
Kinne adds: "If these examinations were that good, you could do away with juries, grand juries, DAs, defense attorneys. And that's not going to happen."
Holden and his colleagues would never argue that polygraphs should be used in place of other evidence, only that it should be considered with it. "I think we should be allowed to testify," Holden says. "We meet the standards of scientific reliability. When we're held accountable for our opinions, when we have to produce our data and charts and files and hold them up to scrutiny, it's going to make us better and better."
Can the crucial interview component of the exam ever be controlled enough to minimize examiner error?
"The proof of the test is the outcome," Holden says. "If we do what we're taught properly and have the skill to understand the subtleties of human interaction and communication, I think we can. It's a goal I'll shoot for till the day I die."
There is something decidedly intriguing--and more than a little scary--about the possibility of polygraphs playing a bigger role in deciding guilt and innocence. But Holden is certain that day is not too far in the future.
"I think the science of polygraphing is ready for court and would make a significant contribution in court. We have an enormous contribution to make. Just ask Ricky Dale Thomas and Adonis Baxter.