Polygraph Examinations | Lie Detector Testing

(636) 391-2188

St. Louis Missouri area   


Professional and Confidential


PDD - Forensic Psychophysiological Detection of Deception








We Use State-Of-The-Art Computerized Polygraph Equipment !

Mid-West Protective Service, Inc.® provides professional and confidential polygraph examination and lie detector testing services.  We have been providing polygraph examination and lie detector testing services for over 17 years.    We use state of the art computerized polygraph instrumentation, and all of our polygraph examiners have extensive law enforcement investigative experience.  Unlike most polygraph testing companies, we are also licensed as a private investigative agency.  Because of our comprehensive investigative experience, we are a leader in the truth verification process. All initial telephone consultations are done at no cost.


Do you need to know if someone is being truthful or being honest?  Do you need to clear your own name or restore your reputation?  Then our professional, trained, and licensed polygraph examiners can assist. Our polygraph examinations are conducted in compliance with legal, ethical, and professional standards.  


People often refer to the polygraph as a “Lie Detector.”  The term polygraph means many writings. The forensic term for the polygraph examination is “Forensic Psychophysiological Detection of Deception (PDD)”. The polygraph instrument records indicators of autonomic arousal.  The polygraph records physiological responses to a series of questions presented to an individual by a qualified polygraph examiner using a validated / approved testing format. The polygraph examiner is then able to decipher the chart polygrams and render a diagnostic opinion as to the veracity of the subject being tested.  During the polygraph examination the following activity is simultaneously and visually monitored / recorded.


1.  Respiratory (breathing) patterns using pneumographs.


2.  Blood pressure and pulse rate (cardiovascular activity) using a blood pressure cuff.


3.  Electrodermal or galvanic skin response is measured through electrodes attached to an examinee’s fingertips.


The three common phases of a polygraph examination are the Pre-Test Phase, In-Test Phase and Post-Test Phase. Properly conducted, a polygraph examination should take a minimum of 90 minutes.



Links below provide additional information:





Polygraph exams that are employment related are done in compliance with the Federal Employee Polygraph Protection Act of 1988 (EPPA)


Polygraph Memberships / Affiations 

  • American Polygraph Association (APA)
  • American Association of Police Polygraphists (AAPP)
  • British & European Polygraph Association (BEPA) 
  • Missouri Polygraph Association