Polygraph Examiner:

Pat Boone - biography

State of Texas Polygraph License # 1104


What is a Polygraph?

A polygraph examination is a scientific test (Psycho-physiological detection of deception (PDD) test) that collects physiological data from a person with the purpose of identifying reactions associated with dishonesty. At least three systems in the human body are recorded during a polygraph examination:

  1. Respiratory activity is monitored by placing the chest tubes across the examinee's upper portion and abdominal portion of the chest. 

  2. Electro-dermal (sweat gland) activity is recorded by placing two small attachments on the fingers or palm of the hand.

  3. Cardiovascular activity (blood pressure and pulse) is collected by a blood pressure cuff.


See the following link for the requirements for minimum instrumentation for a Polygraph Exam given in the State of Texas http://www.tpeb.state.tx.us/consumer.html


What does a polygraph examination entail?

A professional polygraph examination has three phases: a pretest phase, testing phase, and a post-test phase.  A typical polygraph examination will last at least one and half hours or longer.

Pretest Phase:  In the pretest phase, the polygraph examiner will complete the required paperwork and talk with the examinee about the test. During this period the examiner will discuss and review the questions that will be asked, discuss the issue being tested on, and familiarize the examinee with the testing procedures and the instrumentation.

Testing Phase:  The testing phase (chart collection) takes place in a quiet room with no one else present to distract the examinee. The polygraph examiner will attach the components to the person and then ask previously discussed questions designed to be answered yes or no. Data is collected via the components and are recorded in the form of polygraph charts. Polygraph examiners may use conventional instruments, sometimes referred to as analog instruments, or the more modern computerized polygraph instruments.

Post-Test Phase:
 Following the testing phase, the polygraph examiner will analyze the data on the charts and render an opinion as to the truthfulness of the person taking the exam. The examiner, when appropriate, will offer the examinee an opportunity to explain physiological reactions in relation to one or more questions asked during the polygraph examination.

Why are polygraph examinations used?

Polygraph exams are used to verify the truth, determine deception, clear the innocent from alleged wrongdoing, and to help identify the guilty.  Polygraph exams are used for criminal and civil matters, government/law enforcement pre-employment screening, commercial theft investigations and to monitor convicted sex offenders being supervised by probation and parole.  Private parties also request polygraph examinations to help resolve personal matters such as marital or fidelity issues.


Who uses polygraphs?

Polygraph exams are used by federal, state and local law enforcement agencies, U.S. and district attorneys, public defenders, lawyers, private individuals, and parole and probation departments. Private and public companies also use polygraph examinations when authorized under the Employee Polygraph Protection Act of 1988 (EPPA) for acts of theft, sabotage or espionage.


How do I know if the polygraph examiner is qualified/licensed?

Find out if the polygraph examiner is a member of a polygraph association such as American Polygraph Association (APA) or the American Association of Police Polygraphists (AAPP) or one of its affiliates.  You should also verify that your examiner has been to an approved polygraph school and is licensed in your state.  The examiner should have a copy of their license or an identification card that shows that they are are currently licensed. 


When will I know the result of my polygraph exam?

The polygraph exam is scored immediately following the examination phase and the polygraph examiners professional opinion is rendered and the results are given to the to the examinee and later provided in writing.

Who will know about my polygraph exam results?

Release of the results of your polygraph exam are closely restricted. Your exam results will be provided to you, anyone that you designated in writing, the individual/attorney who requested the exam, or the company or governmental agency that requested the examination and anyone under due course of law through the use of a subpoena.



Defense Academy for Credibility Assessment (DACA)

Employee Polygraph Protection Act

Texas Polygraph Examiners Board  

American Association of Police Polygraphist (AAPP)