Marston, Keeler and Larson each shaped the birth of the polygraph in their own way — this history untangles the tangled origins of the lie detector test.
This comprehensive analysis examines the professional rivalries and overlapping contributions of William Marston, John Larson, and Leonarde Keeler — the three men most often credited with inventing the polygraph — and clarifies who actually deserves credit for what.
TL;DR — The Short Version
- William Marston developed the systolic blood pressure deception test at Harvard (1913–1917), proving that physiological responses could indicate deception, but never built a continuous recording instrument.
- John Larson built the first continuously recording multi-channel polygraph in 1921 at Berkeley under August Vollmer, creating the actual device recognized as a polygraph today.
- Leonarde Keeler refined, miniaturized, and commercialized the polygraph (1925–1939), adding the galvanic skin response channel and making it a practical law enforcement tool.
- August Vollmer, Berkeley's pioneering police chief, mentored both Larson and Keeler and created the institutional environment that made the polygraph possible.
- Frye v. United States (1923) — the landmark ruling that excluded Marston's testimony — established the 'general acceptance' standard that shaped evidence law for seven decades.
- The modern polygraph was an incremental achievement — no single inventor deserves sole credit, and all three men contributed essential elements to the instrument used worldwide today.
Who This Guide Is For
- Polygraph professionals seeking a definitive historical reference on the instrument's origins
- Students and researchers studying the history of forensic science
- Legal professionals interested in the backstory behind Frye v. United States
- Anyone curious about who actually invented the lie detector
- Journalists and writers covering polygraph science who need accurate source material
- History enthusiasts interested in early 20th-century American innovation and scientific rivalry
The Question of Who Invented the Polygraph
A Surprisingly Complicated Answer
Ask a simple question — "Who invented the lie detector?" — and you will receive a surprisingly complicated answer. Unlike many landmark inventions, the polygraph has no universally agreed-upon inventor. Instead, at least three men have serious, documented claims to various aspects of its creation, and their overlapping work spans roughly four decades from the early 1900s to the late 1940s.
The three central figures are William Moulton Marston (1893–1947) Verified Cesare Lombroso and the Hydrosphygmograph – Polygraph History
Confirms Lombroso used the hydrosphygmograph in 1895 to measure blood pressure and pulse changes in suspects during interrogation. Critically, Larson also drew upon the instrument developed by Dr. James Mackenzie, a Scottish cardiologist who constructed a clinical polygraph in 1892 capable of simultaneously recording vascular pulses, and later refined it as the "Mackenzie Ink Polygraph" in 1906 with watchmaker Sebastian Shaw Verified Cesare Lombroso and the Hydrosphygmograph – Polygraph History
Confirms Lombroso used the hydrosphygmograph in 1895 to measure blood pressure and pulse changes in suspects during interrogation. The hydrosphygmograph had been developed by other scientists for medical purposes; Lombroso adapted it for forensic use and is generally recognized as the first to employ scientific instrumentation for determining truthfulness Verified Cesare Lombroso and the Hydrosphygmograph – Polygraph History
Confirms Lombroso used the hydrosphygmograph in 1895 to measure blood pressure and pulse changes in suspects during interrogation. Earlier still, Italian physiologist Angelo Mosso used a plethysmograph in the 1870s to study the effects of emotion and fear on cardiovascular activity Verified History of Polygraph – Ohio Polygraph Services
Confirms Mackenzie's 1892 clinical polygraph, Keeler's 1938 addition of psychogalvanometer, and the modern polygraph is a modification of Mackenzie's instrument.
C.D. Lee and the Berkeley Psychograph
Captain Clarence D. Lee, the Chief of Detectives at the Berkeley Police Department, constructed the second polygraph produced by the Berkeley police group in the 1920s [24]Verified Cardiograph – ScienceDirect Topics
Confirms Captain Clarence D. Lee of Berkeley Police built the second polygraph and developed the Berkeley Psychograph in the 1920s. His innovations included a sprocket drive for movement of chart paper instead of Larson's smoked drum method, and an improved means of converting blood pressure signals into a reliable tracing [24]Verified Cardiograph – ScienceDirect Topics
Confirms Captain Clarence D. Lee of Berkeley Police built the second polygraph and developed the Berkeley Psychograph in the 1920s. Lee was an early advocate of the Peak of Tension approach and published "The Instrumental Detection of Deception" in 1953 [24]Verified Cardiograph – ScienceDirect Topics
Confirms Captain Clarence D. Lee of Berkeley Police built the second polygraph and developed the Berkeley Psychograph in the 1920s. He marketed his device, known as the Berkeley Psychograph, at least until the 1950s [24]Verified Cardiograph – ScienceDirect Topics
Confirms Captain Clarence D. Lee of Berkeley Police built the second polygraph and developed the Berkeley Psychograph in the 1920s.
John E. Reid and the Control Question Technique
John E. Reid, a Chicago lawyer and former police officer, developed the Control Question Technique (CQT) in 1947, representing a major breakthrough in polygraph methodology [25]Verified The Polygraph Technique, Part I: Theory – Reid & Associates
Confirms John E. Reid developed the Control Question polygraph technique in the 1940s. The CQT incorporated control questions designed to be emotionally arousing for truthful subjects and less emotionally arousing for deceptive subjects than the relevant questions [25]Verified The Polygraph Technique, Part I: Theory – Reid & Associates
Confirms John E. Reid developed the Control Question polygraph technique in the 1940s. Reid's CQT replaced the Relevant/Irrelevant Question Technique that had been used since Larson's era and remains the most widely used polygraph technique to this day [26]Verified A Review of the Polygraph: History, Methodology and Current Status
Confirms Reid developed the CQT, replacing Keeler's Relevant/Irrelevant Question technique, and that it remains the most widely used technique. Reid also founded his own polygraph school and is known for the broader Reid Technique of interviewing and interrogation [26]Verified A Review of the Polygraph: History, Methodology and Current Status
Confirms Reid developed the CQT, replacing Keeler's Relevant/Irrelevant Question technique, and that it remains the most widely used technique.
Fred Inbau and the Northwestern Crime Lab
Fred E. Inbau, a Northwestern University lawyer and criminologist, served as director of the Scientific Crime Detection Laboratory after it was sold by Northwestern to the Chicago police in 1938 [26]Verified A Review of the Polygraph: History, Methodology and Current Status
Confirms Reid developed the CQT, replacing Keeler's Relevant/Irrelevant Question technique, and that it remains the most widely used technique. He trained police officers and prosecutors in polygraph techniques and co-authored influential manuals with John Reid, including "Lie Detection and Criminal Interrogation" [26]Verified A Review of the Polygraph: History, Methodology and Current Status
Confirms Reid developed the CQT, replacing Keeler's Relevant/Irrelevant Question technique, and that it remains the most widely used technique. The Northwestern Crime Lab was a crucible for polygraph professionalization in the 1930s and 1940s.
Harold E. Burtt and Academic Research
Harold E. Burtt, who became a professor of psychology at Ohio State University in 1923, conducted independent research on deception detection during this period and collaborated with Marston on early deception testing work [27]Verified First Attempts at Practical Use of Instrumental Lie Detection – European Polygraph
Confirms Marston worked with Harold E. Burtt in 1917–18 on early deception testing for the NRC. Burtt authored the first genuine evidence-based law-psychology textbook in 1931, which covered deception detection among other topics [28]Verified Harold Burtt: A Neglected Founder of Psychology and Law
Confirms Harold Burtt was an Ohio State psychologist who authored the first evidence-based law-psychology textbook covering deception detection. He represented the academic wing of polygraph research, providing crucial scholarly context for the field's development. Ohio State University later named a prestigious chair in his honor [28]Verified Harold Burtt: A Neglected Founder of Psychology and Law
Confirms Harold Burtt was an Ohio State psychologist who authored the first evidence-based law-psychology textbook covering deception detection.
Cleve Backster and Later Standardizers
Following Reid's innovations, Cleve Backster developed the Zone Comparison Technique (ZCT) in 1960, building upon the Reid CQT with altered question sequencing [25]Verified The Polygraph Technique, Part I: Theory – Reid & Associates
Confirms John E. Reid developed the Control Question polygraph technique in the 1940s. More significantly, Backster introduced a quantification system for chart analysis, making it more objective and scientific than previous subjective interpretation methods [25]Verified The Polygraph Technique, Part I: Theory – Reid & Associates
Confirms John E. Reid developed the Control Question polygraph technique in the 1940s. His system for numerical evaluation of physiological data became standard procedure in the field [25]Verified The Polygraph Technique, Part I: Theory – Reid & Associates
Confirms John E. Reid developed the Control Question polygraph technique in the 1940s. Other important standardizers include Gordon H. Barland, who received the APA's research award multiple times Verified APA Awards Recipients – American Polygraph Association
Confirms Gordon H. Barland, James A. Matte, Cleve Backster, and other key figures as recognized contributors to the polygraph field, and James Allan Matte, who developed the Quadri-Track technique Verified APA Awards Recipients – American Polygraph Association
Confirms Gordon H. Barland, James A. Matte, Cleve Backster, and other key figures as recognized contributors to the polygraph field. For a look at how modern technology is changing the field, see our article on whether AI can outperform human polygraph examiners.
Comparing Contributions: Who Deserves Credit?
A Framework for Understanding
The question of who "invented" the polygraph depends entirely on what one means by the word. If the question is who first demonstrated that physiological changes could detect deception, the answer is William Marston (with important precursors from Lombroso and Münsterberg). If the question is who built the first multi-channel, continuously recording instrument, the answer is clearly John Larson. If the question is who created the practical, portable, commercially available device that law enforcement actually used, the answer is Leonarde Keeler. And if the question is who created the institutional environment that made the invention possible, the answer is August Vollmer.
The polygraph literature itself reflects this complexity, variously attributing the origins of the modern polygraph to Benussi (1914) or to Larson, who constructed the prototype of the multi-channeled polygraph in 1921 [9]Verified Appendix E: Historical Notes on the Modern Polygraph – National Research Council
Confirms Marston attempted to interest the NRC Committee on Psychology in his work during WWI, and clarifies that most accounts overstate his formal role there. The honest answer is that the modern polygraph was an incremental achievement involving dozens of contributors across multiple decades.
Key Contributions Summarized
Marston (1913–1917): Developed the systolic blood pressure deception test; proved the foundational concept. Published the seminal 1917 paper in the Journal of Experimental Psychology [8]Verified Systolic Blood Pressure Symptoms of Deception – Marston (1917)
Confirms Marston's 1917 article title, publication in the Journal of Experimental Psychology, Volume 2, pages 117–163. His work was the conceptual bedrock upon which everything else was built.
Larson (1921): Built the first continuously recording multi-channel polygraph; established scientific testing protocols; published findings in peer-reviewed journals [14]Verified The Cardio-Pneumo-Psychogram and its Use in the Study of the Emotions – Larson (1922)
Confirms Larson's article title and publication in Journal of Experimental Psychology, Volume 5, 1922. Created the instrument we recognize as a polygraph.
Keeler (1925–1949): Made the polygraph portable, reliable, and commercially viable; added the galvanic skin response channel (1938); patented the Keeler Polygraph (1939); founded the first polygraph school (1948); conducted the first polygraph examination suitable for legal proceedings (1935) [20]Verified The Lie Detector Man: The Career and Cases of Leonarde Keeler
Confirms Keeler conducted the first admissible polygraph examination in court on February 2, 1935, in Portage, Wisconsin [21]Verified Biography of Leonarde Keeler
Documents Keeler's establishment of the first polygraph school and his role in landmark cases.
Vollmer (1905–1932): Created the institutional environment; recruited and mentored Larson and Keeler; commissioned the first practical lie detector; championed scientific policing [4]Verified August Vollmer – Wikipedia
Confirms Vollmer served as Berkeley's first police chief from 1909 to 1932, his role in scientific policing, and his mentorship of Larson and Keeler.
Reid (1947): Developed the Control Question Technique that revolutionized polygraph methodology and remains the dominant approach [25]Verified The Polygraph Technique, Part I: Theory – Reid & Associates
Confirms John E. Reid developed the Control Question polygraph technique in the 1940s. For more on how these contributions impact modern testing, see our polygraph cardiograph channel guide.
The Lasting Legacy and Modern Implications
From Berkeley to the World
The polygraph that emerged from Berkeley in the 1920s has gone on to become one of the most widely used — and most debated — instruments in forensic science. The rivalries and competing claims of its founders set patterns that persist to this day: debates about proper use, scientific validity, standardization, and the appropriate role of technology in determining truth.
The American Polygraph Association, established in 1966, now has over 2,700 members and promotes the highest standards of professional, ethical, and scientific practices Verified APA Awards Recipients – American Polygraph Association
Confirms Gordon H. Barland, James A. Matte, Cleve Backster, and other key figures as recognized contributors to the polygraph field. The field has continued to evolve through contributions from researchers like those at the University of Utah Polygraph Research Group and the Department of Defense Polygraph Institute, now the National Center for Credibility Assessment Verified DOD Polygraph Institute: How DoDPI Standardized Federal Testing
Provides context on federal standardization of polygraph practices. Modern instruments record the same fundamental channels — cardiovascular activity, respiration, and electrodermal activity — that Larson and Keeler first combined, now enhanced with digital recording and computer-assisted analysis.
The Marston Polygraph Academy, a California-based APA-accredited school, carries forward the name of one of polygraph's founding figures. And across the profession, every polygraph examination conducted today draws on the accumulated innovations of Marston, Larson, Keeler, Vollmer, Reid, Backster, and the many others who contributed to the instrument's development. The polygraph's journey from World War I laboratories to modern law enforcement is explored further in our Polygraph in World War I guide and our article on polygraph testing in the 1950s during McCarthyism.
Frequently Asked Questions
Who invented the polygraph lie detector?
The polygraph was not invented by a single person. William Marston developed the foundational blood pressure deception test at Harvard (1913–1917), John Larson built the first continuously recording multi-channel polygraph at Berkeley in 1921, and Leonarde Keeler refined and commercialized it through the 1930s and 1940s. August Vollmer, Berkeley's police chief, provided the institutional environment that made it all possible.
What was Frye v. United States and why is it important to polygraph history?
Frye v. United States (1923) was the landmark case in which the D.C. Circuit Court of Appeals excluded William Marston's systolic blood pressure deception test as evidence. The defendant, James Alphonzo Frye, was convicted of second-degree murder. The court ruled that the test had not gained 'general acceptance' in its scientific field, establishing the Frye Standard that governed admissibility of scientific evidence for seven decades until Daubert v. Merrell Dow Pharmaceuticals in 1993.
What is the difference between Marston's test and Larson's polygraph?
Marston's test was discontinuous — he used a standard blood pressure cuff to take intermittent readings during questioning. Larson's 1921 cardio-pneumo-psychogram was the first instrument to continuously and simultaneously record multiple physiological channels (blood pressure, pulse, and respiration) on a moving paper chart in real time. This continuous recording was the fundamental innovation that defines the modern polygraph.
What role did August Vollmer play in the invention of the polygraph?
August Vollmer, Berkeley's police chief from 1909 to 1932, was the catalyst behind the polygraph's development. He commissioned John Larson to build the first practical lie detector in 1921 and mentored the teenage Leonarde Keeler. Vollmer's broader vision of scientific policing — including requiring college degrees for officers, establishing crime labs, and teaching criminal justice at UC Berkeley — created the environment in which the polygraph could be developed and tested.
Why did Larson and Keeler have a rivalry?
Larson viewed himself as the inventor of the polygraph and believed Keeler received undeserved credit for innovations Larson had originated. Larson also opposed the commercialization and widespread use of the polygraph, believing it should remain a carefully supervised scientific tool. Keeler embraced commercial applications and law enforcement use. Larson spent decades compiling a manuscript documenting his case against Keeler's claims, though it was never published.
What is the connection between Wonder Woman and the polygraph?
William Marston, who developed the systolic blood pressure deception test that was a precursor to the modern polygraph, later created the Wonder Woman comic book character. He famously equipped her with a golden 'Lasso of Truth' that compelled anyone caught in it to tell the truth — a clear homage to his earlier work in deception detection. Marston's wife Elizabeth Holloway Marston, who helped inspire the blood pressure research, also influenced the character's creation.
Who developed the Control Question Technique used in modern polygraph testing?
John E. Reid, a Chicago lawyer and former police officer, developed the Control Question Technique (CQT) in 1947. The CQT replaced the Relevant/Irrelevant Question Technique that had been used since Larson's era and remains the most widely used polygraph technique today. Cleve Backster later refined Reid's approach with the Zone Comparison Technique in 1960, adding a quantification system for more objective chart analysis.
Where is Larson's original polygraph instrument today?
John Larson's original 1921 cardio-pneumo-psychogram is preserved at the Smithsonian Institution's National Museum of American History in Washington, D.C., recognizing its significance as a landmark American invention in forensic science.
What was Leonarde Keeler's most significant contribution to the polygraph?
Keeler's most significant contributions include making the polygraph portable and commercially viable, adding the galvanic skin response (psychogalvanometer) channel in 1938, patenting the Keeler Polygraph in 1939, conducting the first polygraph examination suitable for legal proceedings in 1935, and founding the first polygraph school — the Keeler Polygraph Institute — in Chicago in 1948.
Sources & References
Confirms Marston's birth and death dates (May 9, 1893 – May 2, 1947), his Harvard education, creation of Wonder Woman, and systolic blood pressure test
Confirms Larson became likely the first American policeman with a doctoral degree and created the foundational polygraph technology in Berkeley in 1920
Confirms Keeler's birth and death dates (October 30, 1903 – September 20, 1949), his role in polygraph development, death from stroke, and founding of Keeler Polygraph Institute
Confirms Vollmer served as Berkeley's first police chief from 1909 to 1932, his role in scientific policing, and his mentorship of Larson and Keeler
Confirms Münsterberg was a pioneer of applied psychology at Harvard who supervised graduate students, directed dissertation research, and was an academic mentor to Marston
Confirms Marston was a student of Münsterberg at Harvard and that Elizabeth Holloway Marston inspired the blood pressure test
Confirms Marston's discontinuous technique, Münsterberg's influence, Lombroso's hydrosphygmograph, and Larson's continuous recording innovation
Confirms Marston's 1917 article title, publication in the Journal of Experimental Psychology, Volume 2, pages 117–163
Confirms Marston attempted to interest the NRC Committee on Psychology in his work during WWI, and clarifies that most accounts overstate his formal role there
Confirms Yerkes sponsored tests of Marston's research under the NRC, details of Frye case including James Alphonso Frye as defendant
Confirms Marston collaborated with Hugo Münsterberg on lie detection research at Harvard and that Elizabeth Holloway Marston inspired the blood pressure test
Confirms Vollmer served as Berkeley's chief of police from 1909–1931 (marshal from 1905–1909) and introduced numerous policing innovations
Documents Keeler's transformation of the polygraph from experimental apparatus to practical forensic tool and his establishment of the first polygraph school
Confirms Larson's article title and publication in Journal of Experimental Psychology, Volume 5, 1922
Confirms Mackenzie was a Scottish cardiologist who invented a multi-channel ink polygraph in 1885, refined in 1906 with watchmaker Shaw
Confirms Larson's 1921 article in Journal of the American Institute of Criminal Law and Criminology, Volume 12, pages 390–399
Confirms Larson's balanced but critical perspective on the polygraph and his caution against its use in court proceedings
Confirms Keeler conducted the first admissible polygraph examination in court on February 2, 1935, in Portage, Wisconsin
Documents Keeler's establishment of the first polygraph school and his role in landmark cases
Confirms Keeler suffered a stroke on September 7, 1949 and died September 20, 1949, at age 45 from cerebral hemorrhage
Confirms James Alphonzo Frye was convicted of second-degree murder, and the court excluded systolic blood pressure deception test evidence
Confirms Captain Clarence D. Lee of Berkeley Police built the second polygraph and developed the Berkeley Psychograph in the 1920s
Confirms John E. Reid developed the Control Question polygraph technique in the 1940s
Confirms Reid developed the CQT, replacing Keeler's Relevant/Irrelevant Question technique, and that it remains the most widely used technique
Confirms Marston worked with Harold E. Burtt in 1917–18 on early deception testing for the NRC
Confirms Harold Burtt was an Ohio State psychologist who authored the first evidence-based law-psychology textbook covering deception detection
Confirms Gordon H. Barland, James A. Matte, Cleve Backster, and other key figures as recognized contributors to the polygraph field
Provides context on federal standardization of polygraph practices
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