1. What exactly is a polygraph test?
The word "polygraph" literally means "many writings." What we refer to as a Polygraph or Lie Detector is actually a scientific instrument (not a machine) which is capable of simultaneously recording two or more channels of data. This data is the specific physiological changes produced by an individual when they are asked questions pertaining to a specific area under investigation. These recordings or graphs which are known as "polygrams" are then interpreted by a certified expert or Licensed polygraphist. Polygraph examiners use conventional instruments, often referred to as analog instruments, or computerized instruments.
2. What types of situations can polygraph testing be used?
Polygraph testing is often used to either confirm or exonerate a person's involvement in any suspect activity or wrongdoing. Polygraph testing is of great assistance in the absence of other corroborative evidence (i.e. one person's word against another). Polygraphs are frequently used in the following situations:
Domestic dispute resolution
Media and current affairs
Sexual harassment claims
3. Who uses polygraph examinations?
Three segments of society that use polygraph testing include law enforcement agencies, the legal community, and the private sector/individuals. These segments are further described as follows:
Law Enforcement - Criminal investigations and pre-employment; federal, state, and local law enforcement agencies such as Police and Sheriff s Departments.
Legal Community - Attorneys (Prosecutors, Defense Attorneys and Civil Attorneys) for both criminal and civil matters; Parole and Probation Departments for monitoring purposes
Private Sector - Citizens for personal issues not involving the legal or criminal justice system (i.e. marital infidelity); Companies and Corporations under the restrictions and limitations of EPPA (Employee Polygraph Protection Act); Clinical Treatment Facilities for monitoring and treatment issues; Insurance Investigations; Employee Theft Investigations; Armored car, Security Guard personnel for Pre-employment.
4. What happens during a polygraph test?
A polygraph test consists of three (3) parts:
1) A structured pre-test interview with the examinee
2) The collection of charts (a minimum of three)
3) Chart analysis and post-test interview
More details of the process are:
o The polygraph examiner receives and reviews the facts of the case.
o The examiner formulates the specific test questions based upon the facts of the case and the examinee' s version of the events.
o The examiner explains the test process to the examinee and reviews the facts of the case during the pretest interview. At this time the examiner reads each question to the examinee to make sure each one is easily understood.
o If at any time or for any reason, the examinee feels uncomfortable with the examiner, the examination should be stopped. Arrangements should be made for another examiner to conduct the test at another time.
o The examinee is attached to the polygraph instrument and given additional instructions.
o The questions are read to the examinee three times while they are attached to the polygraph instrument using sensors that measure blood pressure, heart rate, breathing and sweat gland activity. These measurements are charted on graphs or stored in the memory of computerized polygraph units.
o Upon completion of the questions, the examiner will analyze the charts and numerically score the charts to make sure that his analysis is within the acceptable limits of the instrument. This score results in a conclusion that the examinee has answered either truth, deception or is determined to be inconclusive.
o The examiner will transmit the test results to the client verbally as soon as is practical. A written report will be provided if requested.
NOTE: Polygraph exams are conducted in private. No other persons are allowed in the examination room during the test. Exceptions may be made if an examinee requires an interpreter. Most reputable examiners videotape the examination for the protection of all parties involved.
5. What kinds of questions can be asked and how many questions can be asked?
Questions used in a polygraph test must be clear and concise. All test questions must be limited to "yes" or "no" answers from the examinee. The test questions must have definite objective answers and may not be opinions. The test questions must relate to past events of a factual nature. The wording of the questions must only have one interpretation.
There are never any questions pertaining to religion or politics.
There will be no questions pertaining to sexual subject matter during either the interview or polygraph examination unless such subject matter is relevant or necessary to conduct the investigation.
An example of a "good" and "bad" question: Bad - "Did you ever cheat on your wife?"
Good - "Since you married Janet, have you had sexual intercourse with anyone other than Janet?"
Separate issues can not be asked within the same test. Questions in the same test must be related to one another. The examiner can ask about drug use and alcohol use in the same examination, but not ask about drug use and extramarital sex in the same test. Distinctly separate types of issues require separate examinations.
An examiner can usually cover three (3) relevant questions during an exam. This assumes these questions are related to one another (see the question above). It takes about 90 minutes to cover these three questions effectively. If it is necessary to ask more questions, another exam must be designed and conducted, usually at a later time. This will add to the time and cost involved. Test results are usually less reliable with an increase in the number of relevant test questions. A healthy individual can only produce readable polygraph charts for a limited period of time; after this time has passed it is impossible to generate a conclusive polygraph test. Any further testing would need to be scheduled for a different day.
6. What does a polygraph record?
A polygraph instrument will collect physiological data from at least three systems in the human body. Convoluted rubber tubes that are placed over the examinee's chest and abdominal area will record respiratory activity. Two small metal plates, attached to the fingers, will record sweat gland activity, and a blood pressure cuff, or similar device will record cardiovascular activity.
7. How accurate is polygraph testing?
U. S. government studies have concluded that when a qualified examiner conducts the test properly, the polygraph exam is between 87 and 98 percent accurate. It is the most accurate means available for determining the truth or deception of a person answering a direct question.
Considerable scientific research has demonstrated that the pattern of physiological changes during a polygraph test provides the basis for making highly accurate inferences concerning truth or deception.
8. Can someone beat the test?
People don't beat a polygraph test they beat the examiner conducting the test. This is why it is imperative to ensure that the examiner conducting the test is certified and qualified to conduct the test. A polygraph is an instrument that records changes in autonomic reactivity when confronting a given stimulus (question). If a person engages in behaviors that are designed to distort the polygraph tracings then it is the job of a competent and qualified examiner to identify and determine when this is occurring.
In most cases it is easy for a qualified examiner to determine when an examinee is attempting to influence the outcome of the exam. Although some parameters can be consciously controlled these are usually easily detected. Typically truthful examinees are cooperative and follow instructions whereas deceptive examinees will attempt to engage in certain behavior in an effort to distort the tracings. When such behaviors are identified verbal warnings are given and if the behavior continues the test is stopped and a Purposeful Non Cooperation (PNC) result is returned.
The polygraph works by recording changes caused by a person's sympathetic nervous system. This is the part of the nervous system that makes your heart beat and causes you to breathe, it can only be consciously controlled very slightly. Attempts to control breathing or heart rate are usually picked up by the trained examiners. A dishonest person might try to affect the outcome of their examination by using drugs or other countermeasures in an attempt to mask the changes caused by their sympathetic nervous system when they answer a question untruthfully.
A person that is under a physician's care should continue to take their medication as prescribed. Failure to follow the prescribed regimen of any medication could cause a metabolic imbalance and have potentially serious medical consequences for the examinee. Prescription medications taken as prescribed should not normally affect the outcome of a polygraph examination. Ifdrugs or alcohol impairs an examinee at the time of their test, it is usually obvious to the examiner.
Attempts to beat the test using medications use of diazepam (Valium) or methylphenidate (Ritalin) are usually unsuccessful. A study published in 1983 showed that the accuracy rate actually IMPROVED in examinees taking these medications before the test. Ifthe use of drugs is suspected, a pre-test (or post-test) drug screening is advised. While the use of certain drugs and medications may affect the exam, such use generally results in an "inconclusive" test rather than changing the result from deceptive to truthful.
The use of hypnotically induced amnesia to defeat a polygraph examination was the subject of a study published in 1945. While the subjects in this study showed complete posthypnotic amnesia for certain learned words, they recognized the words at the unconscious level.
Some examinees will attempt to defeat the test by inflicting pain on themselves, excessive movement or controlling their breathing. Use of a motion detection chair will identify many of these attempts. The examinee' s fear of detection in answering relevant questions will usually create more measurable responses than self-inflicted pain during the other questions.
It is virtually impossible to change a result from "deceptive" to "truthful" through the use of drugs, medications or other countermeasures prior to an exam. This can be demonstrated through verified accuracy rates as high as 95%.
There are books claiming to tell how to beat the polygraph. Some of the books recommend using medications, drugs, hypnosis or self-inflicted pain in an attempt to beat the test. These countermeasures have been proven ineffective.
One of these books was written by a man that administered over 6,000 tests as part of his job as a police officer. In thousands of tests, he rendered a decision on the truthfulness or deception of the examinee. His decisions affected the employment and the freedom of thousands of people. Now he claims the tests are inaccurate and are not capable of determining truthfulness or deception.
Was he telling the truth then? Or is he telling the truth now?
9. Can nervousness or medications affect the test results?
Being nervous is common. Ifa person is not nervous when they take a polygraph test then that is unusual. Being nervous doesn't cause a person to fail a polygraph test, lying does.
10. Are polygraph results admissible in courts?
This is one of the most common misunderstood issues regarding polygraph testing. The fact of the matter is that it is used in court in certain situations and in certain jurisdictions. Each jurisdiction must be checked to determine admissibility standards; some courts allow the introduction of polygraph evidence while others have not.
In most cases, polygraph evidence is used during pre-trial investigation and preparation rather than during the actual trail. It is the role of the courts and juries to determine guilt or innocence and not the results of a polygraph examination. However, polygraph testing can be a beneficial aid when conducting an investigation. Polygraph testing has allowed investigators to either exonerate or implicate suspects or witnesses. Poly graph testing can substantially save investigators and companies in investigative costs and resources by narrowing the focus of inquiry and providing further investigative leads.
In the 0. J. Simpson civil trial, the results of a polygraph were admitted into evidence and this established a precedent across the nation allowing polygraph examinations trials such as divorce cases.
11. Are special examiners needed for sex crimes?
Most licensed examiners can handle routine sex crimes, but there is a new certification for examiners called "Certified Post-Conviction Sex Offender Examiner" which requires 40 hours of additional specialized training. Ifyour exam involves allegation of a sex crime it is advisable to seek out an examiner with this additional training and certification.
12. Can an employer require an employee to take a polygraph?
Yes, under certain conditions and in compliance with the Employee Polygraph Protection Act of 1988 which mandates:
1) That the employer has suffered a specific, non accidental economic loss of money, merchandise or property and the loss has been reported to the appropriate authorities.
2) That the employee to be tested had access to the missing property or loss which is the subject of the investigation . .
3) That the employer must have reasonable suspicion that the employee was involved in the incident or activity under investigation.
If these conditions exist and the employer desires to have an employee tested, the employer must make the request in ViTiting. This form can be downloaded from our website and must be printed on the employer's letterhead. This request must advise the employee that the exam is voluntary and that no action can be taken against him/her solely for refusing to take it.
The employee must also be advised of the incident under investigation, his/her legal rights, and a number of other notifications required under the law. This request must be presented to the employee at least 2 business days (48 hours) prior to the scheduled exam. Within 48 hours notice the employee must be given their legal rights as defined by the Employee Polygraph Protection Act.
Questions must be limited to the specific loss only. The examiner is not permitted to ask questions about losses other than those listed in the notification form.
If an employee "fails" a polygraph under these conditions, the employer still may not take action against the employee without additional supporting evidence indicating the employee's involvement in the loss.
Exemptions granted by The Employee Polygraph Protection Act of 1988 allow pre-employment polygraph examinations for employees of banks, hospitals, nursing homes, drug warehouses, armored car companies and law enforcement agencies. Ifyou have questions about pre-employment polygraph screening for your employees, please contact us.
13. Can someone under age 18 take a polygraph?
Yes, but the examiner must first have written consent of a parent or guardian. However, most examiners will not test anyone less than 14 years old barring extraordinary circumstances.
14. What should I look for when hiring a polygraph examiner?
The rapport between the examiner and examinee is paramount in conducting an effective polygraph examination. Ifat any time or for any reason, the examinee feels uncomfortable with the examiner, the examination should be stopped. Arrangements should be made for another examiner to conduct the test at another time.
Most importantly, if your state requires licensing, make sure the examiner has a current license.
Every examiner must attend a polygraph-training program, which lasts 7 to 8 weeks. Upon completion of this training the examiner must conduct a certain number of exams under the guidance of an experienced examiner. After this internship period, the school reviews the examiner's work and grants the certification if this work was done to their standards.
Most examiners complete a certain amount of continuing education or advanced training programs. As technology changes, examiners must keep up with new techniques and equipment.
Look for an examiner with professional affiliations and memberships, such as the American Polygraph Association or other professional organizations that set standards for examiners.
Last, you want to be sure that the examiner you choose has experience in the type of situation you are testing for. Someone that has spent all their time doing tests for retail theft and white-collar crimes might not be the best choice to test a sex offender.
15. What is the Employee Polygraph Protection Act of 1988 (EPPA)?
On December 27, 1988, the Employee Polygraph Protection Act (EPPA) became law. This is a federal law that established guidelines for polygraph testing and imposed restriction on most private employers.
This legislation only affects commercial businesses. Local, State and Federal governmental agencies (such as police departments) are not affected by the law, nor are public agencies, such as a school system or correctional institution.
(Link to EPPA)
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