The Backster School of Lie Detection
San Diego, California — Founded by Cleve Backster (1924–2013)
One of the most influential polygraph training institutions in history. Founded by CIA interrogation specialist and APA Past-President Cleve Backster, the school pioneered the Zone Comparison Technique and the first numerical scoring system for polygraph charts — innovations that became the worldwide standard. After 60+ years of operation, the school's legacy now continues through PEAK Credibility Assessment Training Center.
This school is no longer in operation. The Backster School of Lie Detection closed following the passing of Cleve Backster in 2013 and has since been absorbed into PEAK Credibility Assessment Training Center in Cape Coral, Florida. This page is preserved as an archival resource documenting the school's history, contributions, and lasting influence on polygraph science. For current training options, see our accredited polygraph programmes directory.
Accreditations & Recognitions
American Polygraph Association
APA-accredited basic polygraph examiner course — graduates eligible for APA membership and state licensing
American Association of Police Polygraphists
Recognised programme — founder Cleve Backster served as Chairman of Research & Instrumentation for both APA and AAPP
California Bureau for Private Postsecondary Education
Registered institution under California's postsecondary education oversight framework
Leonarde Keeler Memorial Award — 1997
Cleve Backster received the polygraph profession's highest honour — the Leonarde Keeler Memorial Award — in recognition of his distinguished achievements in polygraph research, teaching, and the development of techniques that became the worldwide standard. In 2006, the APA Board of Directors established the Cleve Backster Award, to be presented annually honouring individuals who advance the profession through dedication to standardisation of polygraph principles and practices.
About the Backster School of Lie Detection
The Backster School of Lie Detection was originally founded in New York City in 1960 by Cleve Backster following his departure from the Central Intelligence Agency, where he had established and directed the CIA's polygraph programme. The school later relocated to San Diego, California, where it operated from Suite 403 at 861 6th Avenue — becoming one of the most recognised and influential polygraph training institutions in the world.
Backster's own training in polygraph science traced directly to the instrument's origins: he was trained in 1948 by Leonarde Keeler, co-inventor of the modern polygraph. Before entering the polygraph field, Backster served as a commissioned officer in the U.S. Navy during World War II, then became an interrogation instructor for the U.S. Army Counter-Intelligence Corps at Fort Holabird, Maryland. In 1949, he joined the CIA as an interrogation specialist, where he founded the agency's polygraph programme — a programme that remains active to this day.
Over the course of more than five decades, Backster personally directed over 155 basic polygraph training courses and numerous advanced seminars. He served as guest instructor at the U.S. Department of Defense Polygraph Institute and the FBI Academy, and testified before U.S. congressional hearings on polygraph use in 1964 and 1974. He was a Charter and Life Member of the American Polygraph Association, and from 1978 to 1986 served as Chairman of the Research and Instrumentation Committee of both the APA and the AAPP.
The school's international reach was extraordinary. Over its lifetime, it trained polygraph examiners from over 30 countries spanning law enforcement, government intelligence, and the private sector — including students from Australia, Canada, France, Germany, Israel, Jamaica, Mexico, New Zealand, Panama, Saudi Arabia, South Africa, South Korea, Taiwan, the United Arab Emirates, and the United Kingdom.
Following Backster's passing on 24 June 2013, the school's legacy was continued for a period through Limestone Technologies before being formally absorbed into PEAK Credibility Assessment Training Center in Cape Coral, Florida — an APA-accredited programme led by Director Ben Blalock.
Key Innovations & Contributions
Cleve Backster's contributions to polygraph science reshaped the profession. The techniques he developed at the Backster School became the foundation for virtually all modern zone comparison testing and numerical scoring worldwide.
Backster Zone Comparison Technique (ZCT)
Developed in the early 1960s, the ZCT revolutionised how physiological data from polygraph examinations was interpreted. By comparing responses to relevant, comparison, and neutral questions within defined zones, Backster created a structured, replicable framework that replaced subjective global analysis. The technique and its derivatives were adopted by the U.S. Army Military Police School in 1961 and remain the basis for most modern comparison question testing worldwide.
Numerical Scoring System for Polygraph Charts
Backster developed the first system for the numerical evaluation of polygraph charts — applying positive and negative values to the comparison of relevant and comparison question responses. This semi-objective scoring methodology replaced purely subjective interpretation and was subsequently adopted and modified across the entire profession, including the Federal Zone Comparison Test and the Utah scoring system. Johns Hopkins University Applied Physics Lab used Backster's scoring framework in their research on computer-assisted polygraph chart analysis.
The CIA Polygraph Programme
In 1949, Backster founded the Central Intelligence Agency's polygraph programme while serving as an interrogation specialist. The programme he established remains active to this day, and the protocols he developed during his time at the CIA laid the groundwork for the systematic use of polygraph testing across U.S. intelligence and federal agencies.
Historical Timeline
Cleve Backster Born
Grover Cleveland "Cleve" Backster Jr. is born on 27 February in Lafayette Township, New Jersey. He later attends and graduates from Franklin and Marshall Academy in Lancaster, Pennsylvania.
U.S. Navy Service
Backster enlists in the U.S. Navy and serves as a commissioned officer with active duty in the West Pacific during World War II. Honourably discharged in July 1946.
U.S. Army Counter-Intelligence Corps
Re-enlists with the Army Counter-Intelligence Corps at Fort Holabird, Maryland. Becomes involved in criminal investigation and counterintelligence techniques, developing skills as an interrogation instructor.
Trained by Leonarde Keeler
Receives specialised polygraph training from Leonarde Keeler — co-inventor of the modern polygraph instrument and one of the founding figures in lie detection science.
CIA Polygraph Programme Founded
Joins the Central Intelligence Agency as an interrogation specialist and establishes the agency's polygraph programme — a programme that remains operational to this day.
Backster School of Lie Detection Founded
Founds the Backster School of Lie Detection in New York City. The school later relocates to San Diego, California, and becomes a globally recognised leader in polygraph education.
Zone Comparison Technique & Numerical Scoring Developed
Develops the Backster Zone Comparison Technique and the first numerical scoring system for polygraph charts. These innovations are adopted as the standard throughout the polygraph profession and influence all subsequent scoring methodologies.
Congressional Testimony
Testifies before the United States Congress on the use and validity of polygraph examinations — contributing to the national policy debate on lie detection in government, law enforcement, and the private sector.
Backster Research Foundation Established
Founds the Backster Research Foundation, Inc. to advance research into polygraph technique, psychophysiology, and later, his controversial plant bio-communication experiments — "The Backster Effect."
APA & AAPP Committee Leadership
Serves as Chairman of the Research and Instrumentation Committee for both the American Polygraph Association and the American Association of Police Polygraphists — shaping the profession's technical standards for nearly a decade.
Leonarde Keeler Memorial Award
Receives the polygraph profession's highest honour — the Leonarde Keeler Memorial Award — for distinguished achievements in polygraph research and teaching.
APA Establishes the Cleve Backster Award
The APA Board of Directors creates the Cleve Backster Award — to be presented annually honouring individuals who advance the profession through dedication to standardisation of polygraph principles and practices.
Cleve Backster Passes Away
Cleve Backster passes away in San Diego at the age of 89 after a prolonged illness. His personal papers are later donated to the University of West Georgia Special Collections.
School Absorbed into PEAK
The Backster School of Lie Detection is continued briefly through Limestone Technologies, then formally absorbed into PEAK Credibility Assessment Training Center — an APA-accredited programme headquartered in Cape Coral, Florida, led by Director Ben Blalock.
Historical Faculty & Leadership
Cleve Backster (1924–2013)
Trained by Leonarde Keeler in 1948. CIA interrogation specialist who founded the agency's polygraph programme. Developer of the Zone Comparison Technique and numerical scoring system. APA Charter and Life Member. Keeler Award recipient (1997). Directed 155+ basic courses and served as guest instructor at DoD Polygraph Institute and FBI Academy. Congressional witness on polygraph policy in 1964 and 1974.
Thomas M. Gray
B.A. in International Studies from Ohio State University (1964). Career spanning roles in Central and South America liaising with government and law enforcement agencies. Expertise in multi-lingual interviews and computer systems. Began investigative work in 1979, trained at the Backster School, and became Chief Instructor in 1993. Served as the school's primary point of contact and registrar.
Brian L. English
26-year career in law enforcement, retiring as a sergeant in 1992. Appointed to the San Bernardino County Child Death Review Team. Completed polygraph training at the Backster School in 1993 and conducted examinations for Backster Associates.
Benjamin Newkirk, Ph.D.
Doctorate from Claremont Graduate School in physiological, sensory, and comparative psychology. Professor at San Diego State University and Grossmont College. Extensive research background. Also served as firearms instructor for the San Diego Police Department's Reserve Academy.
Training Programmes (Archived)
Basic Polygraph Examiner Training Course
The school's flagship programme trained students in the Backster Zone Comparison Technique, numerical scoring, chart analysis, question formulation, pre-test interviewing, and post-test interrogation. The curriculum emphasised determining results exclusively through detailed chart analysis — a hallmark of the Backster methodology. Graduates received a certificate serving as a credential toward APA membership and state licensing.
Advanced Seminars & Continuing Education
Backster directed numerous advanced seminars for working polygraph examiners throughout the school's history. These covered advanced chart interpretation, technique refinements, court testimony preparation, legal considerations, and updates to the Zone Comparison methodology. The school's Annual Polygraph Examiner Work Conference was a respected CPD event in the profession.
Curriculum Overview (Archived)
Backster Zone Comparison Technique
The core methodology of the school. Students learned the structured comparison of physiological responses to relevant, comparison, and neutral questions within defined "zones" — the technique that became the worldwide standard for modern polygraph testing.
Numerical Chart Evaluation
Backster's pioneering numerical scoring system — applying positive and negative values to chart responses. Students learned to produce replicable, semi-objective results replacing purely subjective global analysis.
Physiology & Instrumentation
Physiological principles of cardiovascular, respiratory, and electrodermal measurement. Operation and interpretation of computerised polygraph instruments. Taught by Dr. Benjamin Newkirk and supplemented with hands-on instrument practice.
Question Formulation & Pre-Test Interviewing
Construction of legally sound and psychologically effective test questions. Structured pre-test interview protocols, rapport-building techniques, and examinee preparation procedures.
Post-Test Interrogation Techniques
Advanced interrogation methodology applied when deception is indicated through chart analysis. A hallmark of the Backster School's law enforcement focus — preparing students for real-world criminal investigation contexts.
Legal Framework & Court Testimony
Legal considerations of polygraph use, admissibility standards, professional ethics, and preparation for expert witness testimony. Video lectures on court testimony were part of the school's resource library.
Practical Examinations & Simulated Casework
Hands-on practice in individual cubicles equipped with polygraph instruments. Closed-circuit television monitoring during simulated examinations. Students gained familiarity with computer-generated polygraph charts through supervised practical sessions.
Facilities & Training Environment
The Backster School operated from the fifth floor of the San Diego Daily Transcript Building at 861 6th Avenue, Suite 403, San Diego, CA 92101. The facility included spacious classrooms, individual practice cubicles for supervised polygraph sessions, closed-circuit television systems for monitoring student examinations, a video lecture library covering court testimony and legal topics, and a specialist reference library available for student borrowing.
International Reach
Over its 60+ year history, the Backster School trained polygraph examiners from law enforcement agencies, government intelligence services, and the private sector across more than 30 countries worldwide.
Backster School vs. Current Accredited Programmes
| Feature | Backster (Archived) | PEAK (Successor) | NPA (KY) | Marston (CA) |
|---|---|---|---|---|
| Status | Closed / Archived | Active | Active | Active |
| Training Hours | 320 | 400+ | 400 | 400 |
| APA Accredited | ✓ (Historical) | ✓ | ✓ | ✓ |
| AAPP Recognised | ✓ | ✓ | ✓ | ✓ |
| Tuition (Basic) | N/A (Closed) | ~$6,000 | ~$5,500 | $4,895 |
| International Training | ✓ (30+ countries) | ✓ | ✓ | – |
| Signature Technique | Backster ZCT | Multiple Validated | Multiple Validated | Multiple Validated |
| PCSOT Offered | – | ✓ | ✓ | ✓ |
The Backster School is no longer in operation. Its legacy continues through PEAK. All current prices approximate and subject to change. See the full accredited polygraph programmes directory for a complete comparison.
Contact & Location (Archived)
Archived Contact Information
Successor Programme
Frequently Asked Questions
No. The Backster School of Lie Detection is no longer in operation. Following the passing of founder Cleve Backster in June 2013, the school's operations were continued briefly through Limestone Technologies before being formally absorbed into PEAK Credibility Assessment Training Center in Cape Coral, Florida. PEAK is APA-accredited and continues to offer basic and advanced polygraph training.
Cleve Backster (1924–2013) was a CIA interrogation specialist, APA Charter and Life Member, and one of the most influential figures in polygraph history. He founded the CIA's polygraph programme in 1949, developed the Backster Zone Comparison Technique and the first numerical scoring system for polygraph charts in the early 1960s, and established the Backster School of Lie Detection in 1960. He received the Leonarde Keeler Memorial Award in 1997 — the profession's highest honour. He is also known for his controversial research into plant bio-communication, known as "The Backster Effect."
The Backster Zone Comparison Technique (ZCT), developed in the early 1960s, is a structured method for interpreting physiological responses during polygraph examinations. It compares responses to relevant, comparison, and neutral questions within defined zones, replacing subjective global analysis with a replicable framework. The technique was adopted by the U.S. Army Military Police School in 1961 and became the basis for virtually all modern zone comparison testing, including the Federal ZCT and Utah techniques. Backster also developed the associated numerical scoring system that introduced semi-objective chart evaluation to the profession.
The Backster School's legacy continues through PEAK Credibility Assessment Training Center, now headquartered in Lakeland, Florida. PEAK is APA-accredited and AAPP-recognised, and offers basic polygraph examiner courses (400+ hours), PCSOT specialist training, and a range of continuing education courses both in-person and online. Students at PEAK have access to recorded audio and video sessions from Cleve Backster himself. Contact PEAK at [email protected] or (765) 588-9224.
The Backster School's basic Polygraph Examiner Training Course was 320 hours. This was standard at the time of its peak operation, though modern APA accreditation standards now require a minimum of 400 hours for basic polygraph examiner training. The successor programme at PEAK meets the current 400+ hour requirement.
"The Backster Effect" refers to Cleve Backster's controversial research into plant bio-communication, which began in 1966 when he attached polygraph electrodes to a Dracaena cane plant and reported observing stress-like responses. Backster theorised that plants possessed a form of "primary perception" — the ability to respond to human thoughts and emotions. While this research attracted significant public and media interest, it was not accepted by the scientific community, as controlled replication attempts failed to reproduce his findings. Backster's polygraph contributions remain his primary scientific legacy.
Cleve Backster's personal papers — including polygraph association records, biographical files, research foundation documents, experimental research notes, correspondence, lecture materials, and audio-visual recordings — are archived at the University of West Georgia Special Collections at Ingram Library in Carrollton, Georgia. The collection is arranged into thirteen series and is open to researchers.
Continue the Backster Legacy
Explore the successor programme at PEAK, or browse our full directory of APA-accredited polygraph training schools across the United States.
Cleve Backster — Full Biography
From CIA polygraph pioneer to plant whisperer — the full story of Cleve Backster's extraordinary career and controversial research.
Polygraph Knowledge Hub
171-term glossary of psychophysiological detection of deception — the essential reference for students and practitioners.
Compare All Programmes
View our full directory of APA-accredited polygraph training schools across the United States.