The polygraph examination is a psycho-physiological detection of deception technique.  The polygraph examination utilizes computerized forensic testing instrumentation which records physiological responses into software designed by the manufacturer.  Relative changes in blood pressure, rate and strength of pulse rate, electro dermal activity and respiratory inhalation / exhalation patterns are recorded for analysis.

 

The polygraph examination consists of three separate and distinct phases; the Pre-Test Interview, the In-Test Phase and the Post-Test Interview.

 

During the Pre-Test Interview the polygraphist will explain your legal rights and the voluntary nature of the examination.  The polygraphist will also discuss your medical, physical and psychological background.  In addition the polygraphist will go over your background information and will explain how the polygraph instrument works.  You will have the opportunity to discuss in detail any of your concerns.  If you made a mistake on your paperwork  or if you failed to disclose something, be sure to explain it to the polygraphist during the Pre-Test Interview.

 

During the In-Test Phase the polygraphist will review all pertinent test questions with you and will then conduct the Acquaintance Test to help assess your suitability for testing.  Several tests will then be conducted which will include the previously reviewed questions.  There will be no surprise test questions, all questions will be reviewed with you in detail.  The polygraphist will then analyze the results of each test.

 

During the Post-Test Interview the polygraphist will discuss the results of the In-Test Phase and will then provide you with your test results.

Many scientific studies have been done on this question and results of studies revealed that a professionally administered polygraph by an experienced examiner has an accuracy rate in excess of 92%.

You should allow a minimum of three hours, including breaks, for your examination.  Some exams take significantly longer to complete, depending on their complexity and any obstacles that must be overcome before administering the test.

At California Forensic Credibility Assessments we use the Stoelting CPS Pro model polygraph instrument.  The CPS Pro is a computerized polygraph instrument developed by Dr. David Raskin, Ph'D and Dr. John Kircher, Ph'D at the University of Utah, Salt Lake City, Utah.  Comprehensive validation studies were conducted under the authority of the National Institute of Justice and the United States Secret Service.  The CPS Pro software evaluates the body's psycho-physiological responses and computes the readings into the probability of truthfulness and deception.

Through scientific study, professional standards, and subsequent software test design the maximum number of questions that can be asked on a single examination are (4) questions.  The minimum number of questions that can be asked are (2).  The standard strives to ensure a conclusive outcome.  Questions cannot include feelings or thoughts.  Questions should only address specific action/s the examinee did or did not do.

While blood pressure is one of the readings, high blood pressure will not affect the results of your test.

It is normal to be nervous about a polygraph examination.  Nervousness does not prevent the polygraphist from distinguishing between truth and deception.

No.  The polygraph examiner will not force you to take the examination, although polygraph testing may be required by court mandate or your treatment contract.  The polygraphist requires your complete cooperation throughout the test.

Absolutely not.  There is no way the instrument can give you an electrical shock.  When measuring your blood pressure, the sensation is no different than when a doctor checks your blood pressure.  The examination will not cause any physical harm.

Any information disclosed by a client in a Sexual History Polygraph examination cannot be used in any way to initiate a criminal investigation.  The failure of a Sexual History Examination may result in specific sanctions being imposed against the examinee such as being terminated from treatment.  

 Any information disclosed or discovered as a result of a Maintenance Examination may be used by the treatment provider or probation officer in any way they believe would be appropriate.  The treatment provider or probation officer may issue sanctions against any client for failing a polygraph test.

It is important to follow these instructions in order to be prepared for your polygraph examination:

 

 

• Arrive on time for your examination
• Get a full night's sleep the day before your polygraph examination
• Do not consume alcohol or drugs, other than those medications prescribed by a doctor, for forty-eight hours prior to the examination
• Bring all doctor prescribed medications with you to your scheduled examination or a list of those medications
• If you are currently under a doctor's care for any medical condition, be sure to tell the polygraphist before starting the examination
• Bring all completed documentation
• Fully cooperate with your polygraphist
• Allow three hours for your examination
• Be prepared to pay for your examination when you arrive by either cash, debit / credit card or money order

 

If the test results show Significant Responses suggesting the examinee was deceptive (DI), there is no reason to take another test.  However, if the examinee were to disclose new details following the failed examination, the examiner can consider administering a re-examination.

A re-examination is a new examination, independent of any previous examinations, and involves new examination fees.  A re-examination takes place on a different date.

No. The polygraph system does just what it was designed to do and that is measure and record physiological responses to stimuli.  To beat the polygraph one must defeat the examiner.  The examiner watches closely for the use of countermeasures or purposeful non-cooperation (PNC)  Using countermeasures or PNC will result in a failed test.