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YOUR LEGAL RIGHTS | The truth about lie detectors

Knowing that the folks who protect us were hired on the basis of a test that is as reliable as a Ouija board does not exactly make me feel secure.
Attorney David Betras

Ouija boards, phrenology, seances, crystal balls and polygraph machines have one thing in common: They are all based on BS. 

While there is little harm associated with using a Ouija or a medium to converse with your late Aunt Tillie or measuring the bumps and lumps on a subject’s head to determine if they are mentally ill, the results of so called “lie detector” tests can have a devastating impact on the lives of those who are hooked up to one of these totally bogus contraptions.

And believe me, I know from personal experience that they are bogus because on a few occasions during my legal career, I allowed a client to submit to a polygraph “examination.” The outcome: Clients I knew to be guilty passed with flying colors, and those I knew to be innocent failed miserably. In the final analysis, the tests proved one thing: Lie detectors cannot detect a darn thing.

My opinion is backed up by numerous objective studies. According to Leonard Saxe, a psychologist at Brandeis University who has conducted extensive research into polygraphs: “There’s no unique physiological sign of deception. And there’s no evidence whatsoever that the things the polygraph measures — heart rate, blood pressure, sweating and breathing — are linked to whether you’re telling the truth or not.” In an exhaustive report issued in 2003, the National Research Council concluded: “Almost a century of research in scientific psychology and physiology provides little basis for the expectation that a polygraph test could have extremely high accuracy.”

The overwhelming weight of scientific evidence explains why the results of lie detector tests are not admissible as evidence in court unless both the prosecution and the defense agree to let them in — a mistake I will not make again. In addition, suspects are under absolutely no legal obligation to undergo a test, even if law enforcement attempts to pressure them into taking one, and a defendant’s refusal to submit to a polygraph may not be used against them in court. 

The prohibition against the use of polygraphs moved to the workplace when Congress, motivated by the growing use of the unreliable technology by employers, enacted the Employee Polygraph Protection Act of 1998. The EPPA bars employers from:

  • Requiring, requesting, suggesting or causing an employee or prospective employee to take or submit to any lie detector test;
  • Discharging, disciplining, discriminating against, denying employment or promotion or threatening to take any such action against an employee or prospective employee for refusing to take a test, on the basis of the results of a test or for exercising any rights afforded by the Act.

In other words, with few exceptions, people may not be forced to submit to a polygraph to get or keep a job.

The exceptions? Private sector employees who work in security-related fields or the pharmaceutical industry may be hooked up to the infernal machines, and, of course, federal, state and local governments are not covered by the law. There is a special irony in that exclusion because the FBI, CIA, NSA, TSA, ICE and other agencies charged with keeping the nation safe force all applicants and employees to be polygraphed.

Knowing that the folks who protect us were hired on the basis of a test that is as reliable as a Ouija board does not exactly make me feel secure.

—  Attorney David Betras, a senior partner at Betras, Kopp & Harshman LLC., directs the firm’s non-litigation activities and practices criminal defense law in both the state and federal courts. He has practiced law for 35 years. Have a legal question you'd like answered here? Send it to

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