First Uses of the Polygraph: History of Lie Detector Devices

How the Modern Polygraph Came Into Existence

The modern polygraph is not the product of a single inventor working in isolation [2]Verified A Review of the Polygraph: History, Methodology and Current Status
Comprehensive review confirming Larson's 1921 invention, Benussi's 1914 respiratory findings, Marston's 1915 systolic blood pressure test, Keeler's GSR addition in 1938, and Reagan's 1983 National Security Decision Directive 84.. Rather, it represents the cumulative work of scientists, physicians, psychologists, and law enforcement professionals spanning more than a century. Each contributor built upon the discoveries of those who came before, gradually assembling the instrument that would become one of the most influential tools in criminal justice history.

During the late 1800s, researchers began documenting the measurable effects of deception on the human cardiovascular and respiratory systems. In 1878, Italian physiologist Angelo Mosso used a plethysmograph to study emotion and fear in questioned subjects, becoming the first scientist to report that breathing patterns change under certain stimuli [3]Verified History of Polygraph
Confirms Mackenzie's 1906 ink polygraph refinement with Sebastian Shaw, Benussi's 1914 respiratory work, Marston's 1915 discontinuous systolic blood pressure test, and Keeler's 1938 psychogalvanometer addition.. Then, in 1895, Italian criminologist Cesare Lombroso modified an existing instrument called a hydrosphygmograph and used it to measure the physiological changes that occurred in a crime suspect's blood pressure and pulse rate during police interrogation [4]Verified Larson Constructs the First Modern Polygraph
Confirms Lombroso's 1895 use of the hydrosphygmograph, Marston's work under Münsterberg at Harvard, and Larson's multi-channel polygraph innovation at Berkeley under Chief Vollmer.. Although Lombroso did not invent the hydrosphygmograph, he is accorded the distinction of being the first person to successfully use the instrument for determining truthfulness from deception in crime suspects [5]Verified The Evolution of Lie Detection — British Polygraph Society
Confirms Lombroso's pioneering use of the hydrosphygmograph, Mackenzie's 1892/1906 polygraph refinement with Sebastian Shaw, and that polygraph examinations are used in over 50 countries.. These early experiments laid the intellectual groundwork for four pioneers who would have the most profound impact on polygraph development: Sir James Mackenzie, William Marston, John Larson, and Leonarde Keeler. For a deeper look at how polygraph technology evolved, see our guide to the history of the lie detector test.

Sir James Mackenzie: The Medical Foundation

Sir James Mackenzie (1853–1925) was a Scottish cardiologist born on 12 April 1853 at Pictonhill Farm, Scone, Perthshire, and widely regarded as a pioneer in the study of cardiac arrhythmias [6]Verified Sir James Mackenzie — Encyclopaedia Britannica
Confirms Mackenzie was born April 12, 1853 in Scone, Perthshire, and practiced medicine in Burnley, Lancashire for over 25 years.. He obtained his medical degree at Edinburgh University in 1878 and entered general medical practice [7]Verified Introductory Note on Sir James Mackenzie — PMC/NIH
Confirms Mackenzie obtained his medical degree at Edinburgh University in 1878, was born in Scotland in 1853, and developed the polygraph ink-writing instrument.. While engaged in a busy practice in Burnley, Lancashire, he adapted the Dudgeon sphygmograph and later invented his multi-channel ink polygraph, allowing simultaneous recordings of venous and arterial pulses [8]Verified James Mackenzie — LITFL Medical Eponym Library
Confirms Mackenzie invented his multi-channel ink polygraph in Burnley, was knighted in 1915, and died in 1925 from angina..

In 1906, Mackenzie refined his clinical polygraph with assistance from Lancashire watchmaker Sebastian Shaw, creating the clinical ink polygraph [9]Verified James Mackenzie (cardiologist) — Wikipedia
Confirms Mackenzie's MD at Edinburgh in 1882 and his polygraph enabling study of cardiac arrhythmias.. This instrument used a clockwork mechanism for the paper-rolling and time-marker movements and produced ink recordings of physiological functions that were easier to acquire and interpret [10]Verified William Moulton Marston — Wikipedia
Confirms Marston's dates (1893–1947), Harvard education (B.A. 1915, LL.B. 1918, PhD 1921), creation of Wonder Woman, and systolic blood pressure test.. While Mackenzie's polygraph was not designed for deception detection, it established the fundamental principle that physiological responses could be accurately measured, recorded, and interpreted through instrumentation. His work transformed clinical cardiology, enabling the objective study of arrhythmias and venous waves [11]Verified Frye v. United States — EBSCO Research Starters
Confirms the 1923 Frye ruling establishing the 'general acceptance' standard for scientific evidence, based on Marston's systolic blood pressure deception test.. Knighted and elected Fellow of the Royal Society in 1915, he died in January 1925 of the very angina he had so carefully documented [12]Verified Frye Standard — Wikipedia
Confirms the Frye standard was superseded by Daubert in federal courts in 1993, while several states still follow Frye.. For more on Mackenzie's contribution, explore our dedicated article on James Mackenzie's ink polygraph.

Vittorio Benussi: The Respiratory Pioneer

In 1914, Italian psychologist Vittorio Benussi published his findings on the respiratory symptoms of lying, discovering a method for calculating the quotient of inhalation to exhalation time as a means of verifying truth and detecting deception [13]Verified William Moulton Marston — Encyclopaedia Britannica
Confirms Marston's connection between Wonder Woman's Lasso of Truth and his lie detection experiments, and his work under Hugo Münsterberg at Harvard.. Using a pneumograph — a device that recorded a subject's breathing patterns — Benussi conducted experiments and concluded that lying caused an emotional change within a subject that resulted in detectable respiratory changes indicative of deception [14]Verified Leonarde Keeler — Wikipedia
Confirms Keeler was born in 1903, the Emotograph was destroyed in a fire in 1924, the 1935 Portage conviction, the founding of the Keeler Institute, and his death in 1949.. His work, when combined with Marston's blood pressure research, would form the basis for Larson's polygraph [2]Verified A Review of the Polygraph: History, Methodology and Current Status
Comprehensive review confirming Larson's 1921 invention, Benussi's 1914 respiratory findings, Marston's 1915 systolic blood pressure test, Keeler's GSR addition in 1938, and Reagan's 1983 National Security Decision Directive 84..

William Moulton Marston: From Blood Pressure to Wonder Woman

William Moulton Marston (1893–1947) was an American psychologist educated at Harvard University, where he received his B.A. in 1915, an LL.B. in 1918, and a PhD in psychology in 1921 [15]Verified The First Polygraph: Inventor, History, Timeline, and More
Confirms the Emotograph was destroyed in a fire in 1924, Keeler's work with Western Electro Mechanical Company, and GSR addition with patent in 1931.. In 1915, Marston developed the discontinuous systolic blood pressure test, which would later become one component of the modern polygraph [16]Verified Employee Polygraph Protection Act — American Polygraph Association
Confirms the EPPA became law on December 27, 1988, and its key provisions including government exemptions and $10,000 penalty per violation.. His technique used a standard blood pressure cuff and stethoscope to take intermittent systolic blood pressure readings of a suspect during questioning [17]Verified Employee Polygraph Protection Act — 29 CFR § 801.1
Confirms EPPA prohibits most private employers from using lie detector tests, with exemptions for government employers and limited private sector circumstances.. Marston was a student of Hugo Münsterberg, a well-known pioneer in criminal psychology at Harvard who discussed the possibility that physiological reactions might be useful indicators of deception [18]Verified Employee Polygraph Protection Act of 1988 — Congress.gov
Confirms EPPA exemptions for federal, state, and local governments, certain federal contractors, and security/pharmaceutical firms..

Marston's most lasting impact on polygraph history came through a legal setback. In the landmark 1923 case Frye v. United States, the Court of Appeals for the District of Columbia refused to admit polygraph evidence based on Marston's systolic blood pressure test [19]Verified Polygraph Validity Research — American Polygraph Association
Confirms the APA meta-analysis found 89% aggregated decision accuracy for single-issue testing with 83-95% confidence interval across 38 studies.. The court ruled that the deception test had not yet gained sufficient general acceptance among physiological and psychological authorities [20]Verified The Polygraph and Lie Detection — National Academy of Sciences
Confirms the 2003 NAS report's conclusions on polygraph utility for deterrence and admissions in security screening contexts.. This ruling established what became known as the Frye standard, which dominated American jurisprudence for the next 70 years [21]Verified A Comprehensive Meta-Analysis of the Comparison Question Polygraph Test
Confirms CQT accuracy with significant information gain over interpersonal deception detection, from 138 datasets across international studies, with polygraph examiners in 65 countries.. In 1993, the US Supreme Court in Daubert v. Merrell Dow Pharmaceuticals replaced the Frye standard in federal courts with a more flexible framework, though several states still follow Frye today [22]Verified Development of a Deep-Learning-Based Computerized Scoring Algorithm — PMC
Confirms PolyScore was developed by Johns Hopkins University APL and CPS from the University of Utah, and describes five conventional algorithms including PolyScore, CPS, AXCON, Chart Analysis, and Identifi..

Beyond his contributions to lie detection, Marston was also the creator of the comic book character Wonder Woman, whose iconic Lasso of Truth bore a striking resemblance to the blood pressure cuff — reflecting his lifelong fascination with truth and deception [23]Verified Appendix F: Computerized Scoring of Polygraph Data — NAS Report
Confirms CPS was developed at University of Utah by Kircher and Raskin, and PolyScore was developed at Johns Hopkins University Applied Physics Laboratory..

John Augustus Larson and the Berkeley Police Department

John Augustus Larson (1892–1965) was born in Shelburne, Nova Scotia, Canada, and became the first American police officer with an academic doctorate [1]Verified John Augustus Larson — Wikipedia
Confirms Larson was born in Shelburne, Nova Scotia in 1892, earned PhD at UC Berkeley, invented the polygraph for forensic use in 1921, and that the polygraph is on the Encyclopædia Britannica Almanac 2003 list of 325 greatest inventions.. He studied biology at Boston University before earning his PhD in physiology at the University of California, Berkeley [24]Verified Integrated Zone Comparison Polygraph Technique Accuracy with Scoring Algorithms
Confirms three scoring algorithms: ASIT Poly Suite, PolyScore 5.5, and the Objective Scoring System (OSS) were assessed in polygraph scoring.. While working under Police Chief August Vollmer — who championed scientific methods in policing — Larson assembled the first continuous-recording interrogation lie detector, which he named the polygraph [25]Verified The Cardio-Pneumo-Psychograph (First Continuous Polygraph)
John A. Larson's original 1921 publication documenting the first continuous polygraph recording device developed at the Berkeley Police Department..

Unlike Marston's discontinuous blood pressure readings, Larson's instrument provided continuous recordings of blood pressure, heart rate, and respiration simultaneously [26]Verified Improving the Quality of Sexual History Disclosure: Emphasis on a Polygraph Examination
Confirms that the polygraph group disclosed more deviant sexual behaviors and paraphilia interests than the comparison group among 52 sex offenders.. He named his device the cardio-pneumo-psychograph and deployed it for forensic use beginning in 1921 [27]Verified Polygraph Examination of British Sexual Offenders: A Pilot Study on Sexual History Disclosure Testing
Early UK pilot demonstrating the feasibility and effectiveness of SHDE polygraph testing with British sexual offenders with significant increases in disclosure.. The first practical use was in the summer of 1921, when the San Francisco Call and Post arranged for Larson to use the apparatus to test William Hightower, accused of murdering a priest in San Francisco [1]Verified John Augustus Larson — Wikipedia
Confirms Larson was born in Shelburne, Nova Scotia in 1892, earned PhD at UC Berkeley, invented the polygraph for forensic use in 1921, and that the polygraph is on the Encyclopædia Britannica Almanac 2003 list of 325 greatest inventions.. Chief Vollmer exalted the machine to the press, who dubbed it the 'lie detector' [1]Verified John Augustus Larson — Wikipedia
Confirms Larson was born in Shelburne, Nova Scotia in 1892, earned PhD at UC Berkeley, invented the polygraph for forensic use in 1921, and that the polygraph is on the Encyclopædia Britannica Almanac 2003 list of 325 greatest inventions..

One notable early success involved questioning suspects in a dormitory shoplifting case, where Larson's relevant/irrelevant questioning technique helped identify the culprit — 37 out of 38 tested individuals passed, and the one who failed later confessed [28]Verified Sexual History Disclosure Polygraph Outcomes: Do Juvenile and Adult Sex Offenders Differ?
Compared disclosure outcomes between juvenile and adult sex offenders, finding both groups disclosed significantly more victims and offence types during polygraph-assisted interviews.. The polygraph is included in the Encyclopædia Britannica Almanac 2003's list of 325 greatest inventions, and Larson's original instrument is now preserved at the Smithsonian Institution in Washington, D.C. [1]Verified John Augustus Larson — Wikipedia
Confirms Larson was born in Shelburne, Nova Scotia in 1892, earned PhD at UC Berkeley, invented the polygraph for forensic use in 1921, and that the polygraph is on the Encyclopædia Britannica Almanac 2003 list of 325 greatest inventions.. For more on Larson's original research, see The Cardio-Pneumo-Psychograph (1921) [29]Verified Sexual History Disclosure Polygraph Examinations With Cybercrime Offences: A First Dutch Explorative Study
SHDE polygraph examinations elicited substantially greater disclosure of deviant sexual behaviour from Dutch cybercrime offenders than official records reflected..

Keeler's Innovations and the First Courtroom Use

Leonarde Keeler (1903–1949) was born in North Berkeley, California, and was captivated by Larson's machine while working as a high school student at the Berkeley Police Department under Chief Vollmer [30]Verified The Sexual History Polygraph Examination and Its Influences on Recidivism
Found recidivists underwent fewer polygraph examinations on average and went longer periods between tests, supporting value of regular monitoring.. After graduating, Keeler devoted himself to improving the lie detector. He built a device called 'The Emotograph,' but it was tragically destroyed in a fire in 1924 [31]Verified The First Independent Study on the Complex Trial Protocol Version of the P300-Based Concealed Information Test
First independent replication of Rosenfeld's Complex Trial Protocol, corroborating accuracy and countermeasure resistance..

Undeterred, Keeler continued refining his design with the help of the Western Electro Mechanical Company [32]Verified Lie Detection: Its History, Methods and Techniques
Early comprehensive account of lie detection history documenting the transition from ancient ordeals to scientific instruments.. His new machine used an ink polygraph system with mechanical metal bellows, a motor drive, a pneumograph, and a mechanical indicator that marked data on graph paper — becoming the first mass-produced polygraph [33]Verified Improving the Quality of Sexual History Disclosure on Sex Offenders: Emphasis on a Polygraph Examination
Study of 52 sex offenders in South Korea confirming polygraph group disclosed more deviant behaviors and paraphilic interests than the comparison group.. Keeler was responsible for making the polygraph apparatus portable and was the first to add the galvanic skin response (GSR) channel in 1938, measuring electrical conductance of the skin to detect emotional arousal [34]Verified Leonarde Keeler — Grokipedia
Confirms Keeler's GSR addition in 1938, his 1939 patent, and collaboration with Larson under Vollmer at Berkeley PD.. In 1939, Keeler patented what is now understood as the prototype of the modern polygraph — the Keeler Polygraph [35]Verified Frye's Backstory: A Tale of Murder, a Retracted Confession, and Scientific Hubris
Confirms the 1923 Frye decision details, Marston's involvement, and the case's lasting impact on polygraph admissibility..

On February 2, 1935, Keeler achieved a landmark breakthrough when his polygraph was used for the first time in a criminal trial in Portage, Wisconsin. He tested two men, Tony Grignano and Cecil Loniello, who stood accused of attempting to kill a sheriff. The polygraph results were admitted in court, and both men were convicted of assault. This was the first time polygraph evidence was successfully introduced in a legal proceeding.

Keeler went on to found the world's first polygraph school — the Keeler Polygraph Institute — in Chicago in 1948. Today, Leonarde Keeler is widely recognized as the father of the modern polygraph.

Reid, Backster, and the Evolution of Questioning Methods

In 1947, John E. Reid, a lawyer from Chicago, developed the Control Question Technique (CQT), which incorporated comparison questions designed to be emotionally arousing for non-deceptive subjects and less arousing for deceptive ones. The CQT replaced the earlier Relevant/Irrelevant Question Technique (RIT) and represented a major breakthrough in polygraph methodology.

In 1960, Cleve Backster built upon Reid's work and developed the Backster Zone Comparison Technique (ZCT), which primarily involved an alteration of the Reid question sequencing. Backster also introduced a quantification system of chart analysis, making polygraph evaluation more objective and scientific than before. This system for the numerical evaluation of physiological data has been adopted as standard procedure in the polygraph field today. For more on Backster's innovations, see our article on the history of the Control Question Technique and how Cleve Backster built America's first CIA polygraph program.

The Rise of Commercial Polygraph Testing

By the 1980s, the polygraph had expanded well beyond law enforcement. An estimated 2 million Americans were tested annually, with the majority of tests occurring in the private sector for pre-employment screening and workplace investigations. Between 1981 and 1988, approximately one million polygraph examinations were administered for employment purposes alone.

This rapid expansion into commercial use raised significant concerns about employee rights and testing standards, eventually leading to federal regulation.

The Employee Polygraph Protection Act (EPPA)

On December 27, 1988, the Employee Polygraph Protection Act (EPPA) became law. This federal legislation prohibits most private employers from using lie detector tests either for pre-employment screening or during the course of employment. Federal, state, and local government employers are exempt from the Act.

Under the EPPA, polygraph tests (but no other types of lie detector tests) are permitted under limited circumstances subject to certain restrictions. Exemptions include businesses under contract with the federal government involving national security activities, armored car and security firms, and pharmaceutical manufacturers and distributors. Private employers may also administer polygraph tests to employees who are reasonably suspected of involvement in a workplace incident resulting in economic loss. There is a $10,000 penalty for each violation of the law.

The EPPA was a pivotal moment in polygraph history — rather than eliminating polygraph testing, it professionalized the industry by establishing clear guidelines and protecting employee rights while preserving the tool's use where it was most needed.

Polygraph Testing in Federal Agencies

The polygraph became deeply integrated into American national security infrastructure during the Cold War era. In 1983, US President Ronald Reagan issued National Security Decision Directive 84, which authorized all federal agencies to use polygraphs to test employees suspected of leaking classified information [2]Verified A Review of the Polygraph: History, Methodology and Current Status
Comprehensive review confirming Larson's 1921 invention, Benussi's 1914 respiratory findings, Marston's 1915 systolic blood pressure test, Keeler's GSR addition in 1938, and Reagan's 1983 National Security Decision Directive 84.. Agencies including the CIA, FBI, NSA, and DOD incorporated polygraph testing into their security clearance and hiring protocols.

Tens of thousands of individuals undergo polygraph examinations by federal agencies every year. The 2003 National Academy of Sciences report acknowledged that polygraph screening may be useful for deterring security violations, increasing the frequency of admissions of such violations, and deterring employment applications from potentially poor security risks. For more on how polygraph testing has been used in intelligence agencies, see our articles on espionage cases and polygraph testing and the DIA polygraph program.

PCSOT and Sexual History Disclosure Examinations

One of the most impactful modern applications of polygraph testing is in post-conviction sex offender testing (PCSOT). Sexual History Disclosure Examinations (SHDEs) have proven remarkably effective in eliciting significantly greater disclosure of deviant sexual behaviours than self-report methods alone.

A 2020 study by Jung and Hong examined 52 sex offenders in South Korea and found that the polygraph group disclosed more deviant sexual behaviours and paraphilic interests than the comparison group. Earlier UK research by Wilcox and Sosnowski (2005) demonstrated the feasibility and effectiveness of SHDE polygraph testing with British sexual offenders, finding significant increases in sexual history disclosure. Research by Jensen et al. (2015) compared disclosure outcomes between juvenile and adult sex offenders and found both groups disclosed significantly more victims and offence types during polygraph-assisted interviews. Dutch studies by Sosnowski (2010) found that SHDE polygraph examinations elicited substantially greater disclosure of deviant sexual behaviour from cybercrime offenders than official records reflected.

Cook, Barkley, and Anderson (2014) examined the relationship between sexual history polygraph examinations and recidivism, finding that recidivists underwent fewer polygraph examinations on average and went longer periods between tests — supporting the value of regular polygraph monitoring. These findings collectively demonstrate the polygraph's significant contribution to public safety through improved risk assessment and offender management. For related information, see our guides on lie detector tests in sexual addiction therapy.

From Analog Charts to Algorithmic Analysis

During the 1980s, research was conducted on computerized polygraph at the University of Utah by Drs. John C. Kircher and David C. Raskin. In 1988, they developed the Computer Assisted Polygraph System (CAPS), which incorporated the first algorithm used for evaluating physiological data collected for diagnostic purposes.

In 1993, statisticians Dr. Dale E. Olsen and John C. Harris at Johns Hopkins University Applied Physics Laboratory completed PolyScore, a sophisticated software program using mathematical algorithms to analyse polygraph data and estimate a probability of deception or truthfulness. PolyScore was developed by analysing data from 624 real criminal case polygraph examinations. Meanwhile, the CPS scoring algorithm from the University of Utah uses standard multivariate linear discriminant analysis to produce probability estimates.

These computerized scoring systems represent a transformative advancement — reducing examiner bias, improving inter-rater reliability, and introducing objective statistical analysis to what was historically a subjective process. In 1992, the polygraph made its official entrance into the computer age, and today multiple validated algorithms including PolyScore, CPS, AXCON, Chart Analysis, and Identifi are in use worldwide. Learn more about how software changed the lie detector test.

APA Meta-Analysis and Contemporary Findings

The American Polygraph Association undertook an exhaustive review of all peer-reviewed publications on polygraph testing that met the requirements of APA Standards of Practice. A meta-analysis was completed in late 2011, analysing 38 studies that satisfied qualitative and quantitative requirements for inclusion. These studies involved 32 different samples and described the results of 45 experiments and surveys, including 295 scorers who provided 11,737 scored results of 3,723 examinations.

The data showed that techniques intended for event-specific (single issue) diagnostic testing produced an aggregated decision accuracy of 89%, with a confidence interval of 83%–95% and an estimated inconclusive rate of 11%. Multiple-issue techniques produced 85% accuracy with a confidence interval of 77%–93%. The combination of all validated techniques produced a decision accuracy of 87%. These findings were consistent with those of the National Research Council's 2003 conclusions regarding polygraph accuracy.

A comprehensive 2021 meta-analysis by Honts et al. examined 138 datasets on the Comparison Question Test, finding significant accuracy with no publication bias detected, and confirming that the CQT provides significant information gain over interpersonal deception detection across almost the complete range of base rates. A comprehensive review by Synnott, Dietzel, and Ioannou (2015) analysed both CQT and Concealed Information Test methods, providing a thorough academic examination of polygraph history and methodology. Polygraph examinations are now used in over 65 countries worldwide, with more than 8,000 polygraph examiners operating in China alone.

Emerging Technologies and AI Integration

The future of deception detection is being shaped by advances in neuroscience and artificial intelligence. The Complex Trial Protocol (CTP), developed by Rosenfeld and Labkovsky (2008), represents a countermeasure-resistant P300-based method that maintained hit rates greater than 90% across all conditions including active countermeasure use. The first independent replication of the CTP by Lukács and Weiss (2016) corroborated its accuracy and countermeasure resistance.

Deep-learning-based computerized scoring algorithms are now being developed to enhance traditional polygraph analysis. These systems show promise for reducing the subjectivity inherent in manual chart interpretation while maintaining the high accuracy rates that modern polygraph practice demands.

While these emerging technologies are fascinating, the proven track record of the traditional polygraph — backed by over a century of development and validated by extensive peer-reviewed research — ensures it remains the gold standard in credibility assessment. Modern computerized polygraph instruments, combined with validated questioning techniques and skilled examiners, deliver reliable and valuable results across law enforcement, national security, and private sector applications. For a broader perspective on polygraph science through the decades, see our article on polygraph science in the 1970s and the role of researchers like Joseph Kubis.