I Must Not Tell Lies: The Callous (and Absurd) Use of Lie Detectors on Sex Offenders

polygraph“Do you know why I called you in today?”

Clark gave the probation officer a blank stare; of course he knew why she called him to her office. Clark was informed of “deception indicated” as soon as the polygraph was over. He told the polygraph examiner that he was worried about the results because he was in pain due to a hand injury. The polygrapher assured Clark that pain would not skew the results. Clark was still skeptical, and rightfully so.

However, he was not going to load her with more ammunition. She had her “answer” and that was all she cared about.

The probation officer slid a piece of paper and a pen across the desk. Clark had not given her any trouble so she was only going to issue a light sanction of color-coded drug testing for three months. Submitting to drug testing meant that Clark was to call a hotline every morning at 9 AM to listen for the new randomized color. He’d have until 5 PM that day to come in for testing if his color was called.

Clark begrudgingly signed the paper. What choice did he have? The polygraph said he lied, so that was that. It could have been worse; he could have gotten thrown back into jail. He would have to suffer the consequences of explaining to his employer why he needed to leave work if his color was called.

As a registered sex offender, Clark must abide by a dizzying morass of rules and regulations. On probation, those rules are more stringent and expensive. Polygraph tests are designed to assess whether a sexual offender on probation is compliant with the rules and regulations. The underlying theory is that lying is stressful and stress can be quantified via a machine. Thus, a sex offender probationer can be monitored and their risk consistently assessed.

Clark signed on the dotted line upon release from incarceration, but did not realize how invasive and ambiguous the bi-annual mandatory polygraph testing would be.

Have you lied to anyone who trusts you? How many sexual partners have you had? How many times a week do you masturbate? What do you fantasize about when you masturbate? Have you had sexual relations with another person while in a relationship? Have you ever worn clothing meant for the female gender? Since your last polygraph, did you once look at someone under the age of 18? Did you do anything sexual with your victim that you did not tell me?

These questions are representative of the three types of polygraph exams: the instant offense test, the sexual history test, and a maintenance test. The instant offense test attempts to have an offender divulge the crime for which they are to be treated. It is usually administered when an offender denies their crime or is accused of committing a new offense. The sexual history test attempts to uncover any sexual behavior patterns by thoroughly examining a probationer’s previous sexual history. The intent is for probation officers to be able to use this information to better monitor and treat offenders. Finally, the maintenance test is run to assess whether a probationer is compliant with probationary rules and restrictions. For instance, whether or not the offender is using drugs or alcohol, or violating curfew.

In order to assess these questions, polygraph examiners attach varying instruments to a test taker that are designed to measure physiological responses. Sensors are clamped onto fingers to measure perspiration, rubber tubing is placed across the chest to monitor breath patterns, and a blood pressure cuff is attached to the upper arm.

Clark recalled that, “there was also this mat I had to sit on. It was supposed to detect clenching. I just hoped I didn’t have an itch. All the instruments were discomforting. The first couple polygraphs I was scared to even blink during testing.”


Two hours would be a long time to not blink. Each testing session can last up to two hours, and includes a pre-interview portion, the actual exam, and then a follow-up to discuss the results at the close of the session. In order to make their assessment, polygraph examiners compare questions representative of  normative expectations for deceptive or truthful persons with answers to relevant questions. If a person reacts more to the control question than the relevant question, they are seen as “truthful.” A polygrapher then returns one of three possible results – no deception indicated, deception indicated, or inconclusive.

“No deception indicated” is the only acceptable result to a probation officer. If inconclusive, the probationer has thirty days to retake the test, at additional cost. The cost of a polygraph examination was $175 by the time Clark completed his last one. Worse yet, if a probationer fails the polygraph completely or misses an appointment without first seeking a probation officer’s permission, they have a month to retest at an additional cost equal to the first test.

As Clark discovered, “deception indicated” leads to sanctions and potential jail time. The problem is that polygraph determinations are based on the recommendations of one examiner and questionable technology that isn’t admissible in a court of law.  

Polygraph examiners claim to be able to detect physiological arousal from examinees under questioning and determine whether the examinee is lying. These claims are subject to intense scrutiny. Psychologists and the courts have “repeatedly rejected the use of polygraph evidence because of its inherent unreliability.”

One driving critique is that polygraph testing procedures cannot adequately discern the relationship between lies and their appropriate physiological reaction. As Patrick Thomassey, a longtime defense attorney in Allegheny County, said, “I’ve had absolutely very, very guilty people pass polygraphs, and I’ve had people who were as innocent as the new-driven snow flunk them — because so much has to do with the internal mechanism of the person and the examiner’s opinion.”

Furthermore, examinees can employ countermeasures to favorably alter their internal mechanism. A quick Google search pulls up any number of ways to “beat the polygraph.” A recent New York Times article suggests, “envision[ing] the scariest thing you can in order to trigger physiological distress.”  A website against the use of polygraphs proposes “simply biting the side of the tongue” to “augment [your] physiological reactions to the ‘control’ questions.”

Clark figured out another method after he was found to be deceptive.

“I felt backed into a corner so I popped a couple Vicodin. It relaxed and numbed me. I felt like I was floating throughout questioning. I did not want to risk another sanction, especially when I was truthful the first time and labeled a liar. It was clear [that] truth and lies were divided by a thin line. I might as well have some say in which side I was on.” In hindsight Clark realizes this was not the most brilliant of moves, but he was terrified of losing what little freedoms he had.


Clark did have another option besides the sanction: he could have retaken the test. However, the test was expensive and entirely funded out of pocket. Clark did not have that kind of money. Not only did he have employment restrictions while on probation, but he also had to factor in the stigma attached to the label of sex offender. Many employers did not want to risk hiring Clark. Virginia’s sex offender registry requires registrants to list their places of employment. He was lucky to find a minimum wage job, but it didn’t pay all his monthly expenses. Clark said at one point the price of a polygraph test rose from $150 to $175. Taking it twice in the same month would cost $350 more than he had to spend.

In spite of these inherent problems, probation offices are increasingly relying on polygraphs to punish probationary sex offenders. California recently moved towards requiring all paroled sex offenders to undergo polygraph testing. Unlike Clark’s experience in Virginia, test results cannot be used to punish, but rather only to investigate new suspected crimes. An offender in Pennsylvania and in Maine may be jailed for refusing to take a polygraph. The results of a polygraph test ended up forcing a Missouri man to serve out his suspended sentence. Asserting his 5th Amendment right to not self-incriminate and refusing a polygraph test sent a Delaware sex offender on probation to jail. Many other states have similar polygraph regulations.

Polygraph examinations are an unfair regulation sex offenders on probation experience. Results from these so-called “lie detectors” are subjective to an examiner who may be privately contracted to perform the polygraph. Questions are not limited to the crime for which the probationer has been convicted or even to their probation regulations. If the result returns unfavorable, it is then used to induce further sanctions on an already restricted probationer. Worse yet, because the offender is on probation, there is no 5th Amendment protection against self-incrimination These examinations are not only inexact, but also notoriously untrustworthy, which can lead to undue punishment.

Unfortunately, the public largely agrees the punishment is fitting. Punishment is unending and Kafkaesque. Probationary sex offenders not only have to worry about polygraph examinations, but also curfews, Halloween, and travel restrictions. This is in addition to registration and notification, residency restrictions, and GPS monitoring, among other mandates extending far beyond probation. The truth is that research shows these restrictions are largely producing the opposite effect, yet the public advocates for a tighter rein in the interest of safety. In turn the fantasy that sex offenders are deviant and unmanageable is perpetuated. With the absurdity of polygraph testing, we are left questioning what our real intentions are in managing the supposed problem of sex offenders.  

Honesty is not always detected as truth in polygraph regulations. Quicker breathing, heavier sweating, and blood pressure spikes are the gold standard of deceit according to a polygraph. The sex offender is faced with an inherent contradiction, truth or self-control. Polygraphs, in reality, reveal very little; but fail and you’re labelled a liar regardless of the truth. This amounts to little more than criminal wizardry in an effort to treat and monitor sex offenders on probation.  

Magical measures to ferret out the truth, however, are best left to Veritaserum.

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