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Bringing the Truth
(214) 438-3880
(972) 772-7934

You Want Answers? Seek Them Out! Hire Dallas Polygraph Services in Dallas and Fort Worth, TX

NOTICE: Thanks to our clients, we are now able to expand into a larger facility. For your convenience, we will be adding more examiners and investigators to help serve you better. Like us on Facebook for more helpful information. Whether you need to know if someone else is telling the truth or to clear your own name, our professional staff of certified polygraph examiners can help. We work with you to get the answers you require—quickly and discreetly. All polygraph testing is conducted in strict compliance with all legal, ethical, and professional standards, as promulgated by the American Polygraph Association. We are a member-in-good-standing of the Texas Association of Polygraph Examiners and the American Polygraph Association. We use Lafayette lie detector instruments, the same instruments used by the Texas Department of Public Safety and numerous federal agencies. Polygraph appointments can be scheduled throughout the workday, with after hours and weekend times available. Preliminary results of our polygraph examinations are provided on the day of the examination, with detailed written reports generally provided within 72 hours.

Dallas Polygraph Services

Meets the growing demand for professionally conducted polygraph examinations and investigations sought by businesses, private individuals, and law enforcement agencies throughout North Texas. We work with you to get you the answers you need, quickly and discretely, with all testing conducted in compliance with all legal, ethical, and professional standards.

Dallas Polygraph Services is not affiliated or associated with Michael D Park or any of his subsidiary companies such as Dallas Polygraph Counselors, Couples Polygraph Services or Dallas Lie Detector Services.

Professional Credentials

As a direct result of many years of professional training and expertise, the examiners at Dallas Polygraph Services are licensed with the State of Texas, and certified in several specialized areas of polygraph examination, including JPCOT and PSCOT testing, EPPA testing, APA testing standards, testing juveniles, pre-employment testing for governmental agencies and security companies, and others.

Professional Staff

The examiners with Dallas Polygraph Services are all licensed polygraph professionals with many years of experience in lie detector testing, interviewing, investigations, and background screening. Our polygraph examiners attend regular continuing education courses to ensure they remain current in the latest polygraph and interviewing skills methodology.

About Lafayette Instrument and The LX4000

Lafayette Instrument Company is the world’s leading manufacturer of polygraph instrumentation and equipment, distributing credibility assessment instruments to private examiners, government, and military organizations around the world. The LX4000 computer polygraph system records, stores, and analyzes physiological changes during a polygraph examination. The LX4000 system combines conventional polygraph procedure with a sophisticated state-of-the-art computer. Results are derived from the following traditional physiological parameters:
  • Pneumo – Two Respiration Input Channels
  • EDA – Galvanic Skin Response
  • Cardio – Blood Volume / Pulse Rate

A.D. “Skip” Ensley

ad ensley A.D. “Skip” Ensley began his polygraph career as a 1994 graduate of the Backster School of Lie Detection, one of America’s premier polygraph training schools. Mr. Ensley draws on his many years’ experience as a former police officer where he served in numerous capacities including as a uniformed officer, investigator, polygraph examiner, and consultant for law enforcement agencies across the country. Further, Mr. Ensley understands the needs of the business community, having been a business owner himself for several years. It is his blend of hands-on law enforcement experience, in-depth knowledge of all aspects and applications of polygraph examination, impeccable references, and savvy business acumen that makes Mr. Ensley a respected member of the American Polygraph Association, the Texas Association of Polygraph Examiners, and a sought after investigator and examiner. Since obtaining his polygraph certification, Mr. Ensley has performed hundreds of polygraphs on a variety of issues, including pre-employment examinations, criminal and business thefts, infidelity examination, sex offender testing, and others. His vision has helped shape Dallas Polygraph Services into a respected polygraph company, well suited to serve businesses, individual clients, and law enforcement with its wide variety of services.


Walter E. Knight

Walter E. Knight started his polygraph career by graduating from the Backster School of Lie Detection in 1985. He has since retired after 20 years from Texas Department of Criminal Justice as a criminal investigator, polygraph examiner, and program administrator for the Office of the Inspector General the Polygraph Section. He received certification from The Joint Polygraph Committee on Offender Testing in 1996 and since has administered hundreds of sex offender polygraphs. Walter also served as board member for Texas Association of Police Polygraph Investigators. He has been a member of Texas Association of Polygraph Examiners and full member of American Polygraph Association since 1985. Walter has administered more than 10,000 polygraph examinations during his career. Retired from actively performing exams, Walter now acts as a valued resource of Dallas Polygraph Services.


Phone: (214) 438-3880

Fax: (214) 988-0809

9330 LBJ Freeway, Suite 900
Dallas, TX 75243

4500 Mercantile Plaza, Suite 300
Ft Worth, TX 76137