Frequently Asked Questions (FAQs)

How are polygraphs used? Who requests them?
Polygraph examinations are used to protect the public, to verify the truth, to identify the innocent, to determine deception; and to help identify the guilty.  Polygraphs are most commonly used for criminal and civil matters, government and law enforcement pre-employment screening, homeland security, commercial theft investigations, and to monitor convicted sex offenders being supervised by probation and parole, and while under treatment.  Private parties also request polygraph examinations to help resolve personal matters, such as theft, sex crimes, domestic issues (unfaithfulness), etc.

Who can be tested?

Virtually anyone that knows the difference between right and wrong can be administered a polygraph examination. Juvenile subjects must have parental / guardian approval. All polygraphs are voluntary.

How accurate is the polygraph?

The American Polygraph Association (APA) believes that scientific evidence supports the high validity of polygraph examinations. The APA has a compendium of 80 research projects published since 1980 on the validity and reliability of polygraph testing. In research conducted on the validity of field examinations, accuracy rates were in the range of 92 – 98%.
Research clearly indicates that when administered by a competent polygraph examiner, the polygraph test is the most accurate means available to determine truth and deception.

I’m extremely nervous about taking a polygraph, will nerves affect the outcome of my test?

No. All examinees have some type of general nervous tension. It is normal to feel nervous when going into a polygraph, especially if you have never taken one before.

Who can be present in the room during an examination?

Only the examinee and the examiner can be in the room during the examination. Additional people present during the examination will adversely affect the test. All examinations conducted by Thurston Polygraph are recorded from beginning to end.

When will I know the results?

The results of the examination can be determined shortly after the end of the examination and a written report will be emailed to the examination requestor, with the exception of adultery polygraph examinations, which will be reported by the end of the business day after the examination.

Will I know what the questions are prior to the test?
Yes. There are no surprises on a polygraph examination. Before the exam, the examiner will thoroughly explain the whole polygraph process and review the test questions with you prior to administering the examination.

What kind of questions are asked on the exam?

All test questions must be limited to "yes" or "no" answers. ALL QUESTIONS ARE REVIEWED with the examinee BEFORE the exam.  There are no surprises on a polygraph examination. Before the exam, the examiner will thoroughly explain the whole polygraph process and review the test questions with you prior to administering the examination.  The test questions must have definite objective answers and may not be opinions.

How long does the polygraph exam take?

A typical polygraph examination will include a pre-test interview phase, a chart collection phase and a test data analysis phase. The typical polygraph exam will generally last 2 – 3 hours from beginning to end.

Are polygraphs examinations admissible in court?

Polygraph results are admissible in some federal circuits and some states. The United States Supreme Court has yet to rule on the issue of polygraph admissibility so it has been up to individual jurisdictions to allow polygraph results. In the majority of cases, pending polygraph results were stipulated to by opposing attorneys.

How does the polygraph work?

All people have an emergency, or survival system, commonly known as the “fight or flight” system. Any time and individual perceives danger, this system is automatically activated, causing sudden changes to take place within the body to better prepare the person to meet the threat.

If, during the test, the examinee is asked a questions he/she has decided to lie to, his/her brain will perceive this questions as a threat; therefore the body’s emergency system will activate. The examinee will experience sudden changes taking place within his/her body, and simultaneously the polygraph instrument will permanently record them.

For the examinee’s protection, the examiner will run more than one test (asking the same questions more than once). This is to ensure that any changes taking place in the examinee’s body are due to the fear of detection caused by lying to a specific question, and is not exclusively due to a coincidental physiological change.

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