Limestone Technologies and its ParagonX platform sit among today's leading instruments, and this manufacturer profile explains the technology that records a modern lie detector test.
Limestone Technologies Inc., founded in 1999 in Kingston, Ontario, is a leading Canadian polygraph manufacturer best known for the ParagonX system and Polygraph Pro Suite software. Acquired by Lafayette Instrument Company in August 2022, Limestone continues to deliver high-fidelity credibility assessment instrumentation to law enforcement, government agencies, and private practitioners worldwide.
TL;DR — The Short Version
- Limestone Technologies was founded in 1999 in Kingston, Ontario, Canada and is now a subsidiary of Lafayette Instrument Company following its acquisition on August 12, 2022.
- The flagship ParagonX system features the highest native sampling rate (625 samples/sec/channel) in any commercial polygraph instrument, with dual-channel 32-bit ADC, nine Lemo precision connector inputs, and optical isolation exceeding 5,000 mV.
- Limestone's Polygraph Pro Suite software, introduced in 2003, and Lafayette's newer LXEdge platform both support the Paragon series alongside Lafayette's LX6 and LX7 systems.
- In 2017, Limestone acquired the Backster School of Lie Detection, founded in 1959 by Cleve Backster — one of the oldest private polygraph schools in existence at that time.
Who This Guide Is For
- Polygraph examiners evaluating the ParagonX system for purchase
- Law enforcement agencies comparing polygraph manufacturers
- Government credibility assessment procurement officers
- Private practitioners seeking high-fidelity instrumentation
- PCSOT examiners requiring reliable data acquisition hardware
- Polygraph training school graduates selecting their first system
Company Overview
History and Founding
Limestone Technologies Inc. was founded in 1999 in Kingston, Ontario, Canada [1]Verified Limestone Technologies Inc. — LinkedIn Company Profile
Confirms Limestone was founded in 1999 in Kingston, Ontario, and introduced Polygraph Professional Suite in 2003[2]Verified Limestone Technologies — Polygraph UK Glossary
Confirms Limestone is a Canadian manufacturer headquartered in Kingston, Ontario. The company opened its doors with a focus on designing polygraph products that emphasized streamlined test operation, automatic measurement and scoring features, and convenient session sharing and storage [3]Verified Total Care Packages — Limestone Technologies
Confirms Limestone opened its doors in 1999 and details the Total Care Package support program. The company built a knowledgeable software development team that would back the software and provide expedited technical support [3]Verified Total Care Packages — Limestone Technologies
Confirms Limestone opened its doors in 1999 and details the Total Care Package support program.
In 2003, Limestone introduced its Polygraph Professional Suite software, which became internationally recognized in the credibility assessment community [1]Verified Limestone Technologies Inc. — LinkedIn Company Profile
Confirms Limestone was founded in 1999 in Kingston, Ontario, and introduced Polygraph Professional Suite in 2003. For over a decade, Limestone remained committed as a partner in community safety, offering products used in credibility assessment and sex offender management [1]Verified Limestone Technologies Inc. — LinkedIn Company Profile
Confirms Limestone was founded in 1999 in Kingston, Ontario, and introduced Polygraph Professional Suite in 2003.
Limestone Technologies' corporate office was located at 2263 Princess Street in Kingston, Ontario [2]Verified Limestone Technologies — Polygraph UK Glossary
Confirms Limestone is a Canadian manufacturer headquartered in Kingston, Ontario. The company employed a small, specialized team of software engineers, electrical engineers, and knowledgeable sales and service representatives [1]Verified Limestone Technologies Inc. — LinkedIn Company Profile
Confirms Limestone was founded in 1999 in Kingston, Ontario, and introduced Polygraph Professional Suite in 2003. For context on how polygraph technology evolved through key periods leading to modern computerized systems like Limestone's, see our guide on the polygraph industry in the 1990s.
Lafayette Instrument Company Acquisition (2022)
On August 12, 2022, Lafayette Instrument Company acquired Limestone Technologies Inc. [4]Verified Lafayette Instrument Co. Acquires Limestone Technologies
Confirms August 12, 2022 acquisition date, Backster School acquisition in 2017, and Cleve Backster details[5]Verified Truth Be Told — Branford Castle Partners Acquires Polygraph Bolt-on
Official press release confirming Branford Castle/Lafayette acquisition of Limestone Technologies on August 22, 2022. The acquisition was announced on August 22, 2022 via a press release from Branford Castle Partners, a New York-based private equity firm whose portfolio company Lafayette Instrument completed the deal [5]Verified Truth Be Told — Branford Castle Partners Acquires Polygraph Bolt-on
Official press release confirming Branford Castle/Lafayette acquisition of Limestone Technologies on August 22, 2022. The press release was notably titled "Truth Be Told — Branford Castle Partners Acquires Polygraph Bolt-on" [5]Verified Truth Be Told — Branford Castle Partners Acquires Polygraph Bolt-on
Official press release confirming Branford Castle/Lafayette acquisition of Limestone Technologies on August 22, 2022.
Branford Castle Partners had originally acquired Lafayette Instrument in April 2021 as the second transaction for Branford Castle Fund II [6]Verified Branford Castle Cannot Tell a Lie: Fund II Invests in Market-Leading Lie Detection Company
Confirms Branford Castle Partners acquired Lafayette Instrument in April 2021 as Fund II's second transaction. Lafayette sells polygraph products to most federal law enforcement and government security agencies, as well as state, local, and international agencies [6]Verified Branford Castle Cannot Tell a Lie: Fund II Invests in Market-Leading Lie Detection Company
Confirms Branford Castle Partners acquired Lafayette Instrument in April 2021 as Fund II's second transaction.
Jennifer Rider, President of Lafayette Instrument Company, stated that both companies had decades of experience serving the credibility assessment community and expected a seamless integration [4]Verified Lafayette Instrument Co. Acquires Limestone Technologies
Confirms August 12, 2022 acquisition date, Backster School acquisition in 2017, and Cleve Backster details. Laurence Lederer, Managing Partner of Branford Castle, noted that the acquisition expanded Lafayette's position in the polygraph market and extended its international reach [5]Verified Truth Be Told — Branford Castle Partners Acquires Polygraph Bolt-on
Official press release confirming Branford Castle/Lafayette acquisition of Limestone Technologies on August 22, 2022. Stikeman Elliott LLP provided legal advisory services for the transaction [5]Verified Truth Be Told — Branford Castle Partners Acquires Polygraph Bolt-on
Official press release confirming Branford Castle/Lafayette acquisition of Limestone Technologies on August 22, 2022. Terms of the deal were not disclosed [5]Verified Truth Be Told — Branford Castle Partners Acquires Polygraph Bolt-on
Official press release confirming Branford Castle/Lafayette acquisition of Limestone Technologies on August 22, 2022.
As a result of this acquisition, Limestone Technologies now operates as a subsidiary of Lafayette Instrument Company [7]Verified Welcome — Limestone Polygraph by Lafayette Instrument Company
Confirms Limestone Technologies is a subsidiary of Lafayette Instrument Company since August 2022. Lafayette's headquarters at 3700 Sagamore Parkway North in Lafayette, Indiana now serves as the primary contact for Limestone products [7]Verified Welcome — Limestone Polygraph by Lafayette Instrument Company
Confirms Limestone Technologies is a subsidiary of Lafayette Instrument Company since August 2022. For a detailed look at Lafayette's full product line including both Limestone and Lafayette-branded systems, see our Lafayette Instrument LX6 and ParagonX overview.
Backster School of Lie Detection Acquisition (2017)
In 2017, Limestone Technologies acquired the Backster School of Lie Detection [8]Verified Limestone Technologies Acquires Backster School — Blue Line Canada
Confirms Backster School founded in 1959, acquired by Limestone in 2017, and training of Cambodian ACU officials[9]Verified Canada's Backster School Trains Cambodia's Anti-Corruption Unit
Confirms Backster School training programs, international student base, and APA/AAPP/CAPP standards compliance. The school was founded in 1959 by Grover Cleveland "Cleve" Backster Jr. (1924–2013), a former CIA interrogation specialist who is credited with founding the CIA's polygraph program [8]Verified Limestone Technologies Acquires Backster School — Blue Line Canada
Confirms Backster School founded in 1959, acquired by Limestone in 2017, and training of Cambodian ACU officials[10]Verified Cleve Backster, R.I.P.
Confirms Backster founded the oldest private polygraph school in 1959 and developed numerical scoring and Zone Comparison Technique. The Backster School trained law enforcement officers in polygraph techniques and was described as the oldest private polygraph school still in existence at the time of Backster's death [10]Verified Cleve Backster, R.I.P.
Confirms Backster founded the oldest private polygraph school in 1959 and developed numerical scoring and Zone Comparison Technique.
Under Limestone's ownership, the school operated from Kingston, Ontario and trained students from numerous countries including Australia, Canada, Germany, Israel, South Korea, the United Arab Emirates, and the United Kingdom [11]Verified Backster School of Lie Detection — LinkedIn
Confirms Limestone continued training excellence since 1959 and details international student countries. In 2019, Cambodian Anti-Corruption Unit officials graduated from the school after completing a 10-week basic polygraph course [9]Verified Canada's Backster School Trains Cambodia's Anti-Corruption Unit
Confirms Backster School training programs, international student base, and APA/AAPP/CAPP standards compliance. Backster alumni had access to a linguistic assistance program, remote mentorship, and ongoing field assistance programs [9]Verified Canada's Backster School Trains Cambodia's Anti-Corruption Unit
Confirms Backster School training programs, international student base, and APA/AAPP/CAPP standards compliance.
Cleve Backster is also recognized for developing the Backster Zone Comparison Technique, one of the most widely adopted polygraph question formats, and for introducing numerical scoring systems for chart analysis circa 1959–1960 [10]Verified Cleve Backster, R.I.P.
Confirms Backster founded the oldest private polygraph school in 1959 and developed numerical scoring and Zone Comparison Technique[12]Verified Cleve Backster — Psi Encyclopedia
Confirms Backster returned to New York in 1959 and founded the Backster School, and details his CIA polygraph career. For more on the historical foundations of polygraph instrumentation, explore our Berkeley Psychograph history and collector's guide.
Current Products
ParagonX Polygraph System
The ParagonX is Limestone's flagship computerized polygraph system and is described as the pinnacle of biomedical polygraph instrumentation [13]Verified ParagonX 9-Channel Acquisition System — Howell Microscopes
Confirms ParagonX is a 9-channel system with nine flush-mounted Lemo connectors and CE certification. It is a 9-channel acquisition system designed for the professional polygraph examiner who requires high-fidelity data acquisition software and physiological hardware [14]Verified ParagonX Polygraph System — Lafayette Instrument Company
Official product page confirming 625 Hz sampling rate, 9 Lemo inputs, 32-bit dual channel ADC, and >5000 mV optical isolation.
Key technical specifications of the ParagonX include:
- Native sampling rate of 625 samples per second, per channel — which the manufacturer states is the highest in any polygraph instrument [14]Verified ParagonX Polygraph System — Lafayette Instrument Company
Official product page confirming 625 Hz sampling rate, 9 Lemo inputs, 32-bit dual channel ADC, and >5000 mV optical isolation[15]Verified ParagonX Polygraph System — Limestone Technologies
Confirms ParagonX specifications including sampling rate, Lemo connectors, and dual-channel 32-bit architecture
- Dual-channel 32-bit analog-to-digital conversion [14]Verified ParagonX Polygraph System — Lafayette Instrument Company
Official product page confirming 625 Hz sampling rate, 9 Lemo inputs, 32-bit dual channel ADC, and >5000 mV optical isolation
- Optical isolation greater than 5,000 mV, which the manufacturer claims offers examiners twice the performance of other leading polygraph systems [14]Verified ParagonX Polygraph System — Lafayette Instrument Company
Official product page confirming 625 Hz sampling rate, 9 Lemo inputs, 32-bit dual channel ADC, and >5000 mV optical isolation
- Nine flush-mounted Lemo precision connectors for all input channels [14]Verified ParagonX Polygraph System — Lafayette Instrument Company
Official product page confirming 625 Hz sampling rate, 9 Lemo inputs, 32-bit dual channel ADC, and >5000 mV optical isolation
- High retention USB connectivity [14]Verified ParagonX Polygraph System — Lafayette Instrument Company
Official product page confirming 625 Hz sampling rate, 9 Lemo inputs, 32-bit dual channel ADC, and >5000 mV optical isolation
- CE certified instrument [13]Verified ParagonX 9-Channel Acquisition System — Howell Microscopes
Confirms ParagonX is a 9-channel system with nine flush-mounted Lemo connectors and CE certification
The nine input channels on the ParagonX support standard polygraph sensors including pneumo, EDA, and cardiovascular channels, plus additional channels for countermeasure detection (CM channel for pneumatic foot sensor), photoplethysmograph (PLE for blood volume tracing), auxiliary electronic countermeasure sensors (typically arm sensors), and a temperature sensor for ambient room temperature measurement [16]Verified ParagonX 9-Channel System — Howell Microscopes (Paragon Silver)
Confirms additional ParagonX channel details including CM, PLE, Aux1, Aux2 channels and OSS scoring algorithms.
The Lemo connectors used in the ParagonX are medically approved, made of nickel-plated brass, and each connector is key-aligned to ensure an easy and precise connection [14]Verified ParagonX Polygraph System — Lafayette Instrument Company
Official product page confirming 625 Hz sampling rate, 9 Lemo inputs, 32-bit dual channel ADC, and >5000 mV optical isolation. Lemo is a Swiss connector manufacturer whose push-pull connectors are widely used in medical devices, defense, aerospace, and scientific research applications [17]Verified LEMO — Wikipedia
Confirms LEMO connectors are used in medical, military, aerospace, telecommunications, and scientific research applications[18]Verified LEMO Circular Connectors — Official Website
Confirms LEMO connectors are used in diagnostic imaging, surgical tools, defense, and aerospace sectors. Lemo connectors are trusted in surgical instruments, patient monitoring systems, avionics, and particle physics research at facilities like CERN [17]Verified LEMO — Wikipedia
Confirms LEMO connectors are used in medical, military, aerospace, telecommunications, and scientific research applications[18]Verified LEMO Circular Connectors — Official Website
Confirms LEMO connectors are used in diagnostic imaging, surgical tools, defense, and aerospace sectors.
The ParagonX system is available for new purchase and as a trade-in upgrade from older polygraph systems [19]Verified ParagonX Polygraph System Upgrade — Limestone Technologies
Confirms trade-in program for current polygraph systems toward ParagonX upgrade. Lafayette offers discounts when trading in current systems toward a new ParagonX [19]Verified ParagonX Polygraph System Upgrade — Limestone Technologies
Confirms trade-in program for current polygraph systems toward ParagonX upgrade. To compare the ParagonX with competing systems, see our Axciton vs. Stoelting comparison guide and our Axciton CPS technical review.
Polygraph Pro Suite Software
The Polygraph Pro Suite is Limestone's proprietary software platform designed for Limestone Technologies series polygraph systems [20]Verified Polygraph Pro Suite Software — Lafayette Instrument Company
Confirms Polygraph Pro Suite features including ChartSync, session management, and report generation. First introduced in 2003, it provides a user-friendly front-end management system with time-saving features for polygraph examiners [1]Verified Limestone Technologies Inc. — LinkedIn Company Profile
Confirms Limestone was founded in 1999 in Kingston, Ontario, and introduced Polygraph Professional Suite in 2003[20]Verified Polygraph Pro Suite Software — Lafayette Instrument Company
Confirms Polygraph Pro Suite features including ChartSync, session management, and report generation.
Key features of Polygraph Pro Suite include:
- Session management with digital storage of all examination data [20]Verified Polygraph Pro Suite Software — Lafayette Instrument Company
Confirms Polygraph Pro Suite features including ChartSync, session management, and report generation
- Post-test chart review with scoring utilities and algorithms [20]Verified Polygraph Pro Suite Software — Lafayette Instrument Company
Confirms Polygraph Pro Suite features including ChartSync, session management, and report generation
- Auto-fill standardized report templates [20]Verified Polygraph Pro Suite Software — Lafayette Instrument Company
Confirms Polygraph Pro Suite features including ChartSync, session management, and report generation
- Examinee photos, fingerprints, session notes, and report generation [20]Verified Polygraph Pro Suite Software — Lafayette Instrument Company
Confirms Polygraph Pro Suite features including ChartSync, session management, and report generation
- ChartSync utility that synchronizes video, audio, and chart data for comprehensive post-test review [20]Verified Polygraph Pro Suite Software — Lafayette Instrument Company
Confirms Polygraph Pro Suite features including ChartSync, session management, and report generation
- Integrated ESS and ESS-M scoring algorithms [21]Verified Polygraph Professional Suite Version 4.4.0.0 Release Notes
Confirms variable sampling rates, ESS-M report integration, and ChartSync video synchronization features
- OSS-1, OSS-2, and OSS-3 scoring algorithms integrated into the software [16]Verified ParagonX 9-Channel System — Howell Microscopes (Paragon Silver)
Confirms additional ParagonX channel details including CM, PLE, Aux1, Aux2 channels and OSS scoring algorithms
- Variable sampling rate options from 40 to 560 samples per second for Paragon-connected systems [21]Verified Polygraph Professional Suite Version 4.4.0.0 Release Notes
Confirms variable sampling rates, ESS-M report integration, and ChartSync video synchronization features
The software is available for download with a valid Limestone Technologies polygraph serial number [20]Verified Polygraph Pro Suite Software — Lafayette Instrument Company
Confirms Polygraph Pro Suite features including ChartSync, session management, and report generation. The current release is Polygraph Pro v4.6.3.2 [22]Verified Manual Downloads — Limestone Polygraph
Confirms current Polygraph Pro v4.6.3.2 release and LXEdge v1.3.x release notes availability.
LXEdge Software Compatibility
Following the Lafayette acquisition, Limestone Paragon series systems also gained compatibility with Lafayette's newer LXEdge software platform [23]Verified LXEdge Software — Lafayette Instrument Company
Confirms LXEdge is compatible with Lafayette LX6, LX7, and Limestone Paragon series. LXEdge is designed with the future in mind and is compatible with the Lafayette LX6, LX7, and Limestone Paragon series [23]Verified LXEdge Software — Lafayette Instrument Company
Confirms LXEdge is compatible with Lafayette LX6, LX7, and Limestone Paragon series. It offers many key features of LXSoftware with major updates to improve examination efficiency [23]Verified LXEdge Software — Lafayette Instrument Company
Confirms LXEdge is compatible with Lafayette LX6, LX7, and Limestone Paragon series.
This cross-platform compatibility means Paragon system owners now have access to two professional software platforms — Polygraph Pro Suite and LXEdge — giving them flexibility in their workflow. For the latest LXEdge release details, see our LXEdge Version 1.1.6.23 release notes.
Technical Specifications Deep Dive
Sampling Rate and Data Fidelity
The ParagonX's native 625 samples per second per channel represents a significant technical advantage in polygraph instrumentation [14]Verified ParagonX Polygraph System — Lafayette Instrument Company
Official product page confirming 625 Hz sampling rate, 9 Lemo inputs, 32-bit dual channel ADC, and >5000 mV optical isolation. This high sampling rate produces exceptionally detailed physiological waveforms, allowing examiners to identify subtle response patterns that lower-resolution systems might miss. For comparison, the Polygraph Pro Suite software historically defaulted to 80 samples per second, with the ParagonX hardware enabling adjustable rates up to 560 sps in the software [21]Verified Polygraph Professional Suite Version 4.4.0.0 Release Notes
Confirms variable sampling rates, ESS-M report integration, and ChartSync video synchronization features.
High-fidelity data acquisition is particularly valuable in credibility assessment contexts where precise measurement of respiratory, cardiovascular, and electrodermal responses determines examination outcomes. Research into technologies and test formats for credibility assessment has highlighted the importance of advanced instrumentation in improving diagnostic accuracy [24]Verified Development of Technologies and Test Formats for Credibility Assessment
Presents validation data for novel technological approaches including computerized scoring methods that supplement polygraph instrumentation.
Scoring Algorithms: ESS and ESS-M
The Polygraph Pro Suite software integrates several evidence-based scoring algorithms, including the Empirical Scoring System (ESS) and the ESS-M (Empirical Scoring System — Multinomial). The ESS was first described in publication in 2008 and is an evidence-based, standardized method for test data analysis with comparison question test formats [25]Verified ESS-M (Empirical Scoring System — Multinomial) — ResearchGate Profile
Confirms ESS-M was first made available in 2017 as an update to the ESS, an evidence-based standardized scoring method[26]Verified Criterion Validity of the Empirical Scoring System with Inexperienced Scorers
Validates ESS accuracy with confirmed case data including 732 examinations scored by 140 scorers. The ESS-M is an important update to the ESS, first made available in 2017 [25]Verified ESS-M (Empirical Scoring System — Multinomial) — ResearchGate Profile
Confirms ESS-M was first made available in 2017 as an update to the ESS, an evidence-based standardized scoring method.
Raymond Nelson, a research specialist with Lafayette Instrument Company and past president of the American Polygraph Association, is one of the primary developers of the ESS and the OSS-3 computer scoring algorithm [27]Verified Raymond Nelson — APA Magazine / Lafayette Instrument
Confirms Raymond Nelson is a researcher for Lafayette Instrument Company and past President of the APA[28]Verified Scientific Basis for Polygraph Testing — Raymond Nelson
Confirms Nelson is a researcher associated with Lafayette Instrument Company and served as APA President. The ESS-M converts changes in physiological activity from polygraph sensors into numerical scores analyzed using a multinomial reference model and a Bayesian classifier [25]Verified ESS-M (Empirical Scoring System — Multinomial) — ResearchGate Profile
Confirms ESS-M was first made available in 2017 as an update to the ESS, an evidence-based standardized scoring method. Nelson has published numerous studies on all aspects of polygraph testing [27]Verified Raymond Nelson — APA Magazine / Lafayette Instrument
Confirms Raymond Nelson is a researcher for Lafayette Instrument Company and past President of the APA.
The ESS has been validated across multiple studies. In one comprehensive validation, data from 5,192 scored results of 732 confirmed Federal and Utah three-question ZCT examinations were analyzed, scored by 140 experienced and inexperienced scorers in 16 study cohorts [29]Verified Using the Empirical Scoring System
Describes ESS procedures with validation data from 5,192 scored results of 732 confirmed examinations. The Polygraph Pro Suite has been updated to replace the original ESS report with the ESS-M report, with the developer recommending ESS-M for reporting results [21]Verified Polygraph Professional Suite Version 4.4.0.0 Release Notes
Confirms variable sampling rates, ESS-M report integration, and ChartSync video synchronization features.
For broader context on how computerized scoring has advanced the field of credibility assessment, explore our Polygraph Research Database.
Connector and Build Quality
The ParagonX Acquisition System uses nine flush-mounted nickel-plated brass alloy Lemo connectors [13]Verified ParagonX 9-Channel Acquisition System — Howell Microscopes
Confirms ParagonX is a 9-channel system with nine flush-mounted Lemo connectors and CE certification[14]Verified ParagonX Polygraph System — Lafayette Instrument Company
Official product page confirming 625 Hz sampling rate, 9 Lemo inputs, 32-bit dual channel ADC, and >5000 mV optical isolation. Lemo is a Swiss manufacturer founded in 1946, known for producing precision push-pull connectors used across medical, military/aerospace, industrial control, test and measurement, and broadcast applications [17]Verified LEMO — Wikipedia
Confirms LEMO connectors are used in medical, military, aerospace, telecommunications, and scientific research applications[18]Verified LEMO Circular Connectors — Official Website
Confirms LEMO connectors are used in diagnostic imaging, surgical tools, defense, and aerospace sectors. Lemo connectors offer a ruggedized and secure connection using their patented push-pull latching system [14]Verified ParagonX Polygraph System — Lafayette Instrument Company
Official product page confirming 625 Hz sampling rate, 9 Lemo inputs, 32-bit dual channel ADC, and >5000 mV optical isolation.
The use of Lemo connectors in the ParagonX reflects a biomedical engineering approach to polygraph instrumentation. These medically approved connectors provide key-aligned connections that prevent mis-mating and ensure signal integrity during examinations [14]Verified ParagonX Polygraph System — Lafayette Instrument Company
Official product page confirming 625 Hz sampling rate, 9 Lemo inputs, 32-bit dual channel ADC, and >5000 mV optical isolation. The ParagonX is also CE certified, meeting European conformity standards [13]Verified ParagonX 9-Channel Acquisition System — Howell Microscopes
Confirms ParagonX is a 9-channel system with nine flush-mounted Lemo connectors and CE certification. For more on industry certification requirements, see our guide on polygraph manufacturer certifications and ASTM standards.
Who Uses Limestone Technologies
Government and Law Enforcement
Limestone Technologies systems are used by government agencies, law enforcement organizations, and military polygraph units internationally. The Backster School, when operated by Limestone, trained officials from Cambodia's Anti-Corruption Unit [9]Verified Canada's Backster School Trains Cambodia's Anti-Corruption Unit
Confirms Backster School training programs, international student base, and APA/AAPP/CAPP standards compliance, and graduates came from countries spanning every continent [11]Verified Backster School of Lie Detection — LinkedIn
Confirms Limestone continued training excellence since 1959 and details international student countries.
Limestone's international presence was a key factor in the Lafayette acquisition, with Branford Castle noting that the deal extended Lafayette's international market reach [5]Verified Truth Be Told — Branford Castle Partners Acquires Polygraph Bolt-on
Official press release confirming Branford Castle/Lafayette acquisition of Limestone Technologies on August 22, 2022. Lafayette Instrument already served as the U.S. government's main supplier of polygraph instruments [4]Verified Lafayette Instrument Co. Acquires Limestone Technologies
Confirms August 12, 2022 acquisition date, Backster School acquisition in 2017, and Cleve Backster details, and the Limestone acquisition complemented this with additional international distribution channels.
Private Examiners and PCSOT Practitioners
Private practitioners and post-conviction sex offender testing (PCSOT) examiners represent a significant portion of Limestone's user base. The company's product line has always included tools for credibility assessment and sex offender management [1]Verified Limestone Technologies Inc. — LinkedIn Company Profile
Confirms Limestone was founded in 1999 in Kingston, Ontario, and introduced Polygraph Professional Suite in 2003. The ParagonX system is well-suited for PCSOT testing, government screenings, and academic settings [30]Verified Best Polygraph Machine Manufacturers — LieDetectorTest.com
Confirms ParagonX 625 Hz sampling rate, trade-in credits, and PCSOT application context.
For examiners interested in entering the field, visit our become a polygraph examiner guide or explore polygraph training options. State-specific licensing guides are also available for Utah, Arkansas, North Dakota, and Indiana.
Competitive Landscape
Limestone Within the Lafayette Family
Since the 2022 acquisition, Limestone Technologies operates alongside Lafayette's own polygraph product lines. Lafayette Instrument Company now offers both the LX6/LX7 systems under the Lafayette brand and the ParagonX under the Limestone brand [7]Verified Welcome — Limestone Polygraph by Lafayette Instrument Company
Confirms Limestone Technologies is a subsidiary of Lafayette Instrument Company since August 2022. This gives Lafayette the broadest product portfolio of any polygraph manufacturer.
Lafayette Instrument Company was founded in 1947 by Max Wastl and has over 75 years of experience in scientific instrumentation [31]Verified Our Story — Lafayette Instrument Company
Confirms Lafayette founded in 1947, PEAK founded 2016, Limestone acquired 2022, and full company history[32]Verified Lafayette Instrument Company — Founded 1947
Confirms Lafayette has over 75 years of experience and lists Limestone Technologies as a subsidiary. The company's portfolio also includes PEAK Credibility Assessment Training Center (founded 2016), Campden Instruments (acquired 1998), Aurora Scientific (acquired 2023), and Actimetrics (acquired 2023) [31]Verified Our Story — Lafayette Instrument Company
Confirms Lafayette founded in 1947, PEAK founded 2016, Limestone acquired 2022, and full company history[32]Verified Lafayette Instrument Company — Founded 1947
Confirms Lafayette has over 75 years of experience and lists Limestone Technologies as a subsidiary.
The LX6 lease program makes Lafayette systems accessible for new examiners — learn more in our LX6 lease program guide.
Market Position vs. Other Manufacturers
In the professional polygraph market, the major manufacturers include Lafayette Instrument (including Limestone), Stoelting Company, and Axciton Systems. Each manufacturer offers distinct advantages.
The ParagonX's primary competitive differentiators are its 625 Hz native sampling rate — the highest among commercial polygraph instruments [14]Verified ParagonX Polygraph System — Lafayette Instrument Company
Official product page confirming 625 Hz sampling rate, 9 Lemo inputs, 32-bit dual channel ADC, and >5000 mV optical isolation — its dual-channel 32-bit ADC [14]Verified ParagonX Polygraph System — Lafayette Instrument Company
Official product page confirming 625 Hz sampling rate, 9 Lemo inputs, 32-bit dual channel ADC, and >5000 mV optical isolation, and its medical-grade Lemo connectors [14]Verified ParagonX Polygraph System — Lafayette Instrument Company
Official product page confirming 625 Hz sampling rate, 9 Lemo inputs, 32-bit dual channel ADC, and >5000 mV optical isolation. The system has been recognized by examiners who value ultra-high sampling rates and superior waveform rendering [30]Verified Best Polygraph Machine Manufacturers — LieDetectorTest.com
Confirms ParagonX 625 Hz sampling rate, trade-in credits, and PCSOT application context.
For a comprehensive manufacturer comparison, see our guide to The Stoelting Company's 140 years of polygraph innovation and our Keeler Polygraph instruments history.
Software and Support Ecosystem
Total Care Packages
Since opening its doors in 1999, Limestone Technologies has emphasized customer support through its Total Care Packages [3]Verified Total Care Packages — Limestone Technologies
Confirms Limestone opened its doors in 1999 and details the Total Care Package support program. These packages are optional but include immediate instrument replacement coverage and unlimited software upgrades for three years [3]Verified Total Care Packages — Limestone Technologies
Confirms Limestone opened its doors in 1999 and details the Total Care Package support program. Importantly, all Limestone Technologies clients are entitled to free software updates and technical support for life [3]Verified Total Care Packages — Limestone Technologies
Confirms Limestone opened its doors in 1999 and details the Total Care Package support program.
All Polygraph Pro and PrefTest Pro Silver and Gold solutions include a three-year Total Care Package as standard [3]Verified Total Care Packages — Limestone Technologies
Confirms Limestone opened its doors in 1999 and details the Total Care Package support program. This lifetime support commitment was a differentiator for Limestone in the market.
Training and Education Resources
Through its parent company Lafayette Instrument, Limestone system users have access to PEAK Credibility Assessment Training Center, which provides the highest-quality credibility assessment training and consulting services [33]Verified PEAK Credibility Assessment Training Center
Confirms PEAK's mission to provide highest quality credibility assessment training and consulting services. PEAK was founded in 2016 by Lafayette to meet the growing need for scientifically driven credibility assessment training [31]Verified Our Story — Lafayette Instrument Company
Confirms Lafayette founded in 1947, PEAK founded 2016, Limestone acquired 2022, and full company history.
Lafayette also offers online LXEdge training events and maintains a comprehensive library of reference documents, including publications by Raymond Nelson on topics ranging from EDA primers to ESS scoring tools [34]Verified Reference & Bibliography Downloads — Lafayette Polygraph
Confirms Raymond Nelson publications on ESS, EDA, and polygraph scoring tools available through Lafayette. For aspiring examiners, explore polygraph training options and learn about state requirements in Florida.
The Evolution of Credibility Assessment Technology
Research Context
The development of polygraph instrumentation like the ParagonX reflects broader trends in credibility assessment technology. Research has explored a range of technologies beyond the traditional polygraph, including thermal imaging systems and computerized scoring methods that could supplement or enhance traditional instrumentation [24]Verified Development of Technologies and Test Formats for Credibility Assessment
Presents validation data for novel technological approaches including computerized scoring methods that supplement polygraph instrumentation. The evolution from analog pen-on-paper systems to advanced digital platforms with 32-bit resolution and 625 Hz sampling demonstrates the field's commitment to scientific rigor.
Studies on emerging neurotechnologies for lie detection have examined fMRI and EEG-based approaches, noting that despite laboratory advances, critical gaps in measurement validity and standardization remain [35]Verified Emerging Neurotechnologies for Lie Detection: Promises and Perils
Examined ethical and legal implications of neuroscience-based lie detection technologies[36]Verified Emerging neurotechnologies for lie-detection: Where are we now?
Found critical gaps in measurement validity and standardization of neurotechnology-based deception detection. This research context underscores the continued importance of well-validated psychophysiological approaches — like those implemented in the ParagonX system — in practical credibility assessment settings.
The ongoing development of technologies for credibility assessment has been a subject of scholarly inquiry across legal and technical domains [37]Verified Technologies in the twilight zone: early lie detectors, machine learning and reformist legal realism
Reveals dual-system phenomenon where polygraphs flourished in employment screening despite courtroom exclusion[38]Verified Alternate technologies
Foundational research relevant to credibility assessment technology alternatives. Canadian jurisprudence regarding polygraph and emerging neuroscience technologies has also explored the distinction between traditional lie detection and newer brain-based approaches [39]Verified Brain fingerprint or lie detector: does Canada's polygraph jurisprudence apply to emerging forensic neuroscience technologies?
Examines Canadian legal framework for polygraph and emerging neuroscience technologies — relevant to Canadian manufacturer context. For practitioners interested in their legal rights and obligations, see our guide on whether you can refuse a lie detector test.
Pros
- Highest native sampling rate (625 Hz per channel) of any commercial polygraph instrument
- Dual-channel 32-bit analog-to-digital conversion for exceptional data resolution
- Medical-grade Lemo precision connectors — same brand used in surgical and aerospace applications
- Optical isolation exceeding 5,000 mV for superior signal quality
- Nine input channels supporting comprehensive physiological data collection including countermeasure detection
- CE certified instrument meeting European conformity standards
- Backed by Lafayette Instrument Company — the U.S. government's main polygraph supplier — since 2022
- Dual software support: both Polygraph Pro Suite and LXEdge platforms
- Lifetime free software updates and technical support for all clients
- Integrated ESS-M and OSS-3 evidence-based scoring algorithms
- Trade-in upgrade program available for legacy and competitor systems
Cons
- Now a subsidiary brand rather than an independent manufacturer — purchasing decisions ultimately route through Lafayette
- Paragon-series sensors use their own ecosystem and are not directly interchangeable with Lafayette LX6/LX7 accessories
- USB connectivity only — no Bluetooth wireless option on the ParagonX
- Smaller established user base compared to the Lafayette LX6 line
- Backster School of Lie Detection is no longer operational as a standalone school
Frequently Asked Questions
When was Limestone Technologies founded?
Limestone Technologies Inc. was founded in 1999 in Kingston, Ontario, Canada [1]Verified Limestone Technologies Inc. — LinkedIn Company Profile
Confirms Limestone was founded in 1999 in Kingston, Ontario, and introduced Polygraph Professional Suite in 2003[2]Verified Limestone Technologies — Polygraph UK Glossary
Confirms Limestone is a Canadian manufacturer headquartered in Kingston, Ontario. The company introduced its Polygraph Professional Suite software in 2003 [1]Verified Limestone Technologies Inc. — LinkedIn Company Profile
Confirms Limestone was founded in 1999 in Kingston, Ontario, and introduced Polygraph Professional Suite in 2003.
Is Limestone Technologies still an independent company?
No. Limestone Technologies was acquired by Lafayette Instrument Company on August 12, 2022, and now operates as a subsidiary [4]Verified Lafayette Instrument Co. Acquires Limestone Technologies
Confirms August 12, 2022 acquisition date, Backster School acquisition in 2017, and Cleve Backster details[5]Verified Truth Be Told — Branford Castle Partners Acquires Polygraph Bolt-on
Official press release confirming Branford Castle/Lafayette acquisition of Limestone Technologies on August 22, 2022[7]Verified Welcome — Limestone Polygraph by Lafayette Instrument Company
Confirms Limestone Technologies is a subsidiary of Lafayette Instrument Company since August 2022. The acquisition was facilitated by Branford Castle Partners, a New York-based private equity firm that owns Lafayette [5]Verified Truth Be Told — Branford Castle Partners Acquires Polygraph Bolt-on
Official press release confirming Branford Castle/Lafayette acquisition of Limestone Technologies on August 22, 2022.
What is the ParagonX sampling rate?
The ParagonX has a native sampling rate of 625 samples per second, per channel, which the manufacturer states is the highest in any commercial polygraph instrument [14]Verified ParagonX Polygraph System — Lafayette Instrument Company
Official product page confirming 625 Hz sampling rate, 9 Lemo inputs, 32-bit dual channel ADC, and >5000 mV optical isolation. This provides exceptionally high-resolution physiological data capture.
How many input channels does the ParagonX have?
The ParagonX has nine input channels with flush-mounted Lemo precision connectors [14]Verified ParagonX Polygraph System — Lafayette Instrument Company
Official product page confirming 625 Hz sampling rate, 9 Lemo inputs, 32-bit dual channel ADC, and >5000 mV optical isolation. These channels support pneumo, EDA, cardiovascular, countermeasure detection, photoplethysmograph, auxiliary sensors, and temperature measurement [16]Verified ParagonX 9-Channel System — Howell Microscopes (Paragon Silver)
Confirms additional ParagonX channel details including CM, PLE, Aux1, Aux2 channels and OSS scoring algorithms.
What software is compatible with Limestone Paragon systems?
Limestone Paragon series systems are compatible with two software platforms: Polygraph Pro Suite (Limestone's proprietary software, current version 4.6.3.2) and LXEdge (Lafayette's newer software platform) [20]Verified Polygraph Pro Suite Software — Lafayette Instrument Company
Confirms Polygraph Pro Suite features including ChartSync, session management, and report generation[23]Verified LXEdge Software — Lafayette Instrument Company
Confirms LXEdge is compatible with Lafayette LX6, LX7, and Limestone Paragon series. Both offer chart recording, scoring algorithms, and report generation tools.
Can I trade in an older polygraph for a ParagonX?
Yes. Lafayette offers a trade-in program where you can trade in your current polygraph system to receive discounts on a new ParagonX system [19]Verified ParagonX Polygraph System Upgrade — Limestone Technologies
Confirms trade-in program for current polygraph systems toward ParagonX upgrade. Contact Lafayette directly for current trade-in values and eligible systems.
What scoring algorithms does the Polygraph Pro Suite include?
Polygraph Pro Suite integrates the OSS-1, OSS-2, and OSS-3 scoring algorithms, as well as the ESS and ESS-M (Empirical Scoring System — Multinomial) [16]Verified ParagonX 9-Channel System — Howell Microscopes (Paragon Silver)
Confirms additional ParagonX channel details including CM, PLE, Aux1, Aux2 channels and OSS scoring algorithms[21]Verified Polygraph Professional Suite Version 4.4.0.0 Release Notes
Confirms variable sampling rates, ESS-M report integration, and ChartSync video synchronization features. The ESS-M, developed by Raymond Nelson and colleagues, uses a multinomial reference model and Bayesian classifier for evidence-based test data analysis [25]Verified ESS-M (Empirical Scoring System — Multinomial) — ResearchGate Profile
Confirms ESS-M was first made available in 2017 as an update to the ESS, an evidence-based standardized scoring method.
What happened to the Backster School of Lie Detection?
Limestone Technologies acquired the Backster School of Lie Detection in 2017 [8]Verified Limestone Technologies Acquires Backster School — Blue Line Canada
Confirms Backster School founded in 1959, acquired by Limestone in 2017, and training of Cambodian ACU officials. The school was originally founded in 1959 by Cleve Backster [8]Verified Limestone Technologies Acquires Backster School — Blue Line Canada
Confirms Backster School founded in 1959, acquired by Limestone in 2017, and training of Cambodian ACU officials[10]Verified Cleve Backster, R.I.P.
Confirms Backster founded the oldest private polygraph school in 1959 and developed numerical scoring and Zone Comparison Technique. While the school is no longer operational as a standalone entity, its legacy continues through PEAK Credibility Assessment Training Center under Lafayette Instrument [10]Verified Cleve Backster, R.I.P.
Confirms Backster founded the oldest private polygraph school in 1959 and developed numerical scoring and Zone Comparison Technique[33]Verified PEAK Credibility Assessment Training Center
Confirms PEAK's mission to provide highest quality credibility assessment training and consulting services.
Where can I buy a Limestone ParagonX system?
Since Limestone Technologies is now a subsidiary of Lafayette Instrument Company, ParagonX systems are available through Lafayette's sales channels. Contact Lafayette Instrument Company at (765) 423-1505 or visit limestonetech.com or lafayettepolygraph.com [7]Verified Welcome — Limestone Polygraph by Lafayette Instrument Company
Confirms Limestone Technologies is a subsidiary of Lafayette Instrument Company since August 2022. You can also book a consultation with our team for equipment guidance.
Does the ParagonX have Bluetooth connectivity?
No. The ParagonX uses a high-retention USB connection for data acquisition [14]Verified ParagonX Polygraph System — Lafayette Instrument Company
Official product page confirming 625 Hz sampling rate, 9 Lemo inputs, 32-bit dual channel ADC, and >5000 mV optical isolation. Unlike the Lafayette LX6 and LX7 which offer both USB and Bluetooth, the ParagonX relies on wired USB connectivity.
Sources & References
Confirms Limestone was founded in 1999 in Kingston, Ontario, and introduced Polygraph Professional Suite in 2003
Confirms Limestone is a Canadian manufacturer headquartered in Kingston, Ontario
Confirms Limestone opened its doors in 1999 and details the Total Care Package support program
Confirms August 12, 2022 acquisition date, Backster School acquisition in 2017, and Cleve Backster details
Official press release confirming Branford Castle/Lafayette acquisition of Limestone Technologies on August 22, 2022
Confirms Branford Castle Partners acquired Lafayette Instrument in April 2021 as Fund II's second transaction
Confirms Limestone Technologies is a subsidiary of Lafayette Instrument Company since August 2022
Confirms Backster School founded in 1959, acquired by Limestone in 2017, and training of Cambodian ACU officials
Confirms Backster School training programs, international student base, and APA/AAPP/CAPP standards compliance
Confirms Backster founded the oldest private polygraph school in 1959 and developed numerical scoring and Zone Comparison Technique
Confirms Limestone continued training excellence since 1959 and details international student countries
Confirms Backster returned to New York in 1959 and founded the Backster School, and details his CIA polygraph career
Confirms ParagonX is a 9-channel system with nine flush-mounted Lemo connectors and CE certification
Official product page confirming 625 Hz sampling rate, 9 Lemo inputs, 32-bit dual channel ADC, and >5000 mV optical isolation
Confirms ParagonX specifications including sampling rate, Lemo connectors, and dual-channel 32-bit architecture
Confirms additional ParagonX channel details including CM, PLE, Aux1, Aux2 channels and OSS scoring algorithms
Confirms LEMO connectors are used in medical, military, aerospace, telecommunications, and scientific research applications
Confirms LEMO connectors are used in diagnostic imaging, surgical tools, defense, and aerospace sectors
Confirms trade-in program for current polygraph systems toward ParagonX upgrade
Confirms Polygraph Pro Suite features including ChartSync, session management, and report generation
Confirms variable sampling rates, ESS-M report integration, and ChartSync video synchronization features
Confirms current Polygraph Pro v4.6.3.2 release and LXEdge v1.3.x release notes availability
Confirms LXEdge is compatible with Lafayette LX6, LX7, and Limestone Paragon series
Presents validation data for novel technological approaches including computerized scoring methods that supplement polygraph instrumentation
Confirms ESS-M was first made available in 2017 as an update to the ESS, an evidence-based standardized scoring method
Validates ESS accuracy with confirmed case data including 732 examinations scored by 140 scorers
Confirms Raymond Nelson is a researcher for Lafayette Instrument Company and past President of the APA
Confirms Nelson is a researcher associated with Lafayette Instrument Company and served as APA President
Describes ESS procedures with validation data from 5,192 scored results of 732 confirmed examinations
Confirms ParagonX 625 Hz sampling rate, trade-in credits, and PCSOT application context
Confirms Lafayette founded in 1947, PEAK founded 2016, Limestone acquired 2022, and full company history
Confirms Lafayette has over 75 years of experience and lists Limestone Technologies as a subsidiary
Confirms PEAK's mission to provide highest quality credibility assessment training and consulting services
Confirms Raymond Nelson publications on ESS, EDA, and polygraph scoring tools available through Lafayette
Examined ethical and legal implications of neuroscience-based lie detection technologies
Found critical gaps in measurement validity and standardization of neurotechnology-based deception detection
Reveals dual-system phenomenon where polygraphs flourished in employment screening despite courtroom exclusion
Foundational research relevant to credibility assessment technology alternatives
Examines Canadian legal framework for polygraph and emerging neuroscience technologies — relevant to Canadian manufacturer context
Confirms Limestone Technologies Inc was founded in 1999
Provides biography of Backster including founding of Backster School and CIA career
Whatever equipment is used, results come from the examiner — find a lie detector test near you and review current pricing at professional locations near you.