Polygraph & Lie Detector Test 

Confidential & Professional


(636) 391-2188

Polygraph examination and lie detector testing services. Located in the St. Louis Missouri area, Mid-West Protective Service, Inc.® provides unmatched professional and confidential truth verification services.  We use state of the art computerized polygraph instrumentation.

We provide services to individuals, attorneys, therapists, law enforcement agencies, insurance companies, government, financial institutions and corporations.

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

All of our 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 have been a leader in the truth verification process for over 17 years.

People often refer to the polygraph as a “Lie Detector.” The term polygraph means many writings. The forensic term is “Forensic Psychophysiological Detection of Deception (PDD)”.

The polygraph records autonomic arousal and physiological responses to a series of questions presented to an individual by a qualified examiner using a validated / approved testing format. The 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 or use of disposable solid gel electrodes attached to the hand.

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





Missouri Licensed Private Investigative Agency # 2010008268
P.O. Box 124
St. Louis, MO  63022-0124