A polygraph is used to monitor a persons

Dr. Ekman’s work in the field of deception detection largely focuses on nonverbal communication of emotion observed in the face and body.

Table of Contents Show

The challenges of deception detection
Do lie detectors actually work?
B. Sample Condition Language
C. Purpose
D. Method of Implementation

The challenges of deception detection

There is no single, definitive sign of deceit itself; no muscle twitch, facial expression, or gesture proves that a person is lying with absolute certainty. Therefore, most modern-day methods of deception detection heavily rely on a variety of methods to collect, analyze and interpret emotional and physiological data.

However, any data collected merely expose emotional clues that may or may not be related to deception. For example, sweaty palms during a job interview could indicate an interviewee’s fear of being caught in a lie about their qualifications. Or, sweaty palms could be illustrating their fear that the interviewer won’t believe their qualifications despite being totally honest on their resume. Or, their palms could be sweaty because they’re worried about something else entirely, like a sick child at home.

There are still many more possible reasons why a person might experience sweating palms, especially during high stakes scenarios. To determine the actual cause, further investigation and analysis is needed. Jumping to conclusions, while easy to do, can be harmful to everyone involved and must be avoided.

Do lie detectors actually work?

The polygraph lie detector works on the same principles as detecting behavioral betrayals of deceit, and it is vulnerable to the same problems. The polygraph exam does not detect lies, just signs of emotion and requires further investigation.

A lie detector test is a device that measures the involuntary physiological changes of a subject’s body as the subject responds to a question or statement. Polygraphs are the most popular lie detector tests used in the United States. Polygraphs measure physiological arousal factors, including heart rate, blood pressure, respiration, perspiration, and skin conductivity. The theory of the lie detector test is that these physiological responses will be different when the subject is truthful versus when the subject lies. Therefore, the term ‘lie detector test’ is a misnomer of sorts, since the test does not speak to the truth of the answer or statement, but rather to the fear, stress, and anxiety of the subject as they answer.

The administrator of the test first differentiates between the subject’s physiological response to answering a question honestly and answering dishonestly, and then looks for those responses as a series of questions are asked. Different examiners utilize different questioning techniques. Usually, the subject of the test will be asked direct questions and control questions and their response will be observed as they answer. Alternatively, the subject’s response may be observed as they hear and react to statements or information that are read out loud to them.

The use of lie detector tests such as polygraphs is controversial as their validity can be questionable. Notably, the test is incapable of differentiating between the physiological factors that often accompany dishonesty, and those factors that may simply be a result of the subject’s anxiety at undergoing questioning. Because there is no uniform psychological and physiological response to dishonesty, someone lying could be very calm while they answer, while another person answering truthfully could be very anxious. Moreover, countermeasures exist that may be employed by subjects to help them ‘beat’ the test.

Due to the unreliable nature of lie detector tests, the results from these tests and the inferences of the examiner are generally inadmissible as evidence during a trial. Most state and federal jurisdictions have per se rules against the admittance of lie detector evidence. Some states allow admittance of lie detector evidence only if there is a stipulation between the parties agreeing to the admittance. Although the Federal Rules of Evidence do not explicitly bar lie detector evidence in federal courts, such evidence is nonetheless blocked in most circuits by Rule 702, as the science behind lie detector tests is unreliable and prone to error. The Supreme Court decided in United States v. Scheffer that the exclusion of lie detector evidence does not violate a defendant’s right to a fair trial, even if the defendant wishes the evidence to be admitted.

Although the results are usually inadmissible as evidence, lie detector tests can nonetheless be useful in interrogations during criminal investigations. Many confessions have been made after a criminal suspect fails a lie detector test. However, any results of a lie detector test conducted on a criminal defendant that become publicized can be very influential on public opinion of the case, especially if picked up by the news media.

Federal and most state law bans employers in the private sector from requiring employees and prospective employees to submit to a lie detector test. If an employee decides to submit to a test, these laws also prohibit an employer from taking adverse employment action against an employee based upon the results. Some states allow exceptions for embezzlement concerns, in which case the testing procedure is heavily regulated and often monitored. The government may use polygraphs as part of personnel screening for employment, especially for positions dealing with national security.

[Last updated in June of 2020 by the Wex Definitions Team]

wex
- THE LEGAL PROCESS
- evidence
- wex definitions

Under 18 U.S.C. § 3563(b)(9), the court may provide that the defendant “undergo available medical, psychiatric, or psychological treatment.”

Under 18 U.S.C. § 3563(b)(22), the court may provide that the defendant “satisfy such other conditions as the court may impose.”

B. Sample Condition Language

You must submit to periodic polygraph testing at the discretion of the probation officer as a means to ensure that you are in compliance with the requirements of your supervision or treatment program.

C. Purpose

This condition serves the statutory sentencing purposes of public protection, deterrence, and rehabilitation. 18 U.S.C. § 3553(a)(2)(B)-(D).
The polygraph examination is used to provide historical information about the defendant’s past behaviors, which is used for assessing risks and targeting treatment interventions, and to increase disclosure of activities, which may serve as a deterrent to re-offending behavior during the supervision period.
This condition enables the probation officer to satisfy the statutory requirements to keep informed as to the conduct and condition of the defendant, report the defendant’s conduct and condition to the sentencing court, and aid the defendant and bring about improvements in his or her conduct and condition. 18 U.S.C. §§ 3603(2)-(3).

D. Method of Implementation

The physical and psychological harm caused by sex offenses is particularly traumatic, and probation and pretrial services officers should give priority to minimizing the impact on victims and to preventing new sex crimes from occurring. Not all persons charged with or convicted of sex offenses are alike. Rather, they present a spectrum of criminogenic risk and therapeutic need. Officers’ investigation and supervision techniques should vary accordingly.
The polygraph test measures and records physiological responses such as heart rate, blood pressure, breathing patterns, and galvanic skin response while a person is asked and responds to specific questions. Testing consists of taking physiological measurements, interpreting the results, and offering an opinion by a professional polygraph examiner regarding deception.
Types of Polygraph Examinations
1. Sexual History Disclosure: A sexual history disclosure examination is used to investigate the examinee’s lifetime history of involvement in unknown or unreported offenses and other sexual compulsion, sexual preoccupation, or sexual deviancy behaviors. The instant offense may also be examined if the defendant exhibits denial regarding the commission of, or circumstances surrounding, the crime of conviction.
2. Maintenance and Monitoring:
  1. A maintenance examination is used to verify the defendant’s compliance with treatment and supervision conditions. Maintenance examinations are administered periodically, usually every six months. Maintenance polygraph examinations cover a wide variety of sexual behaviors and compliance issues that may be related to victim selection, deviancy activities, or high-risk behaviors.
  2. A monitoring examination may be used to investigate the possibility of new unlawful sexual behavior while on supervision based on concerns expressed by the supervision and treatment team. Other relevant questions dealing with behaviors related to probation and treatment compliance should not be included.
3. Issue-Specific: Issue-specific examinations can be used to follow up on previous unresolved/deceptive maintenance/monitoring examinations.
The probation officer should collaborate with the polygraph examiner in the design of the questions presented during a polygraph test. The questions should consider any treatment issues (if the defendant is in treatment), behavior that is not in compliance with the conditions of supervision, and other supervision concerns.
Polygraph examinations, which consist of interviews before, during, and after the polygraph test itself, may detect deception from the person’s demeanor during the interviews, deter unwanted activities by persons who know they will be asked about such activities, and elicit admissions or confessions of undesired activity.1
Under approved judiciary procedures, polygraph results may be used to increase the level of supervision, modify treatment plans, or generate a separate investigation. A polygraph result may not be used as the sole basis to revoke supervision.2
If the defendant refuses to answer a specific question during the polygraph examination or in any other interview on the grounds that it is incriminating, the probation officer may not compel (e.g., through threat of revocation) the defendant to answer the question. If there is uncertainty about whether the question may lead to a realistic chance of incrimination, the probation officer should refer the matter to the court to make this determination.3
Probation officers must be aware of situations that may lead to reasonably foreseeable risk of harm to a third party (see: Chapter 2, Section XII), which may include information received during a polygraph examination.
After the polygraph test is administered, the probation officer should interview the defendant to discuss the results and future treatment and supervision needs.

1 National Research Council, The Polygraph and Lie Detection (Washington, D.C.: The National Academies Press, 2003).

2 For a further discussion of guidance provided to federal probation officers during polygraph examinations, which has been endorsed by the Criminal Law Committee of the Judicial Conference of the United States, see Stephen E. Vance, Looking at the Law: An Updated Look at the Privilege Against Self-Incrimination in Post-Conviction Supervision, 75 Fed. Probation 33, 37 (June 2011).

3 Id.