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BAKER GROUP INTERNATIONAL is comprised of former military, law enforcement, and intelligence professionals — a unique team of international experts with decades of experience in providing intelligence, credibility assessment, strategy and planning support, risk and threat management, decision support, crisis response, psychological analysis & selection vetting and personal security team training for individuals, global corporations and governments.



E. Gary Baker, Ph.D. is widely known as an early VSA pioneer and considered by many as the true “father” of forensic digital voice stress analysis having practiced psychophysiological detection of deception since early 1974. He worked closely with the three inventors of VSA and participated in many early validation studies. Col. Charles McQuiston was a mentor. The International Society of Stress Analysts in 1981 awarded the title of “Analyst” by examination and peer review. In ISSA he was very active, served on the Ethics Committee and the Research & Development Committee. The title “Fellow” was bestowed in 1985. He earned a certificate in 1984 and a diploma in 1988 in Polygraph Science and Lie Detection Technology after 4596 hours of combined classroom and independent study. Advanced certifications have been awarded by ISSA and the American Polygraph and Voice Stress Association.

He was a founding member of Stress Analysis Association of Nebraska (SAAN) and served on the Nebraska Truth Verification Licensing Board, covering VSA and Polygraph examiners, from 1982 to 1990. He has been designated and testified as an Expert Witness in forensic truth verification, legal investigations, and physical security, in District and County Courts. He has provided his professional services to major corporations, governments, law enforcement, and intelligence agencies.

The many US Nuclear Power Generating Stations accepted the Baker forensic VSA, polygraph and clinical psychological testing for personnel screening of applicants for un-escorted access to nuclear facilities and for specific examinations. The Baker organization screened over 10,000 applicants.

He is the principal instructor for VSA, Polygraph, Interview & Interrogation and Kinesic Behavior Analysis skills. He personally conducts DVSA Certified Law Enforcement Examiner Courses. His VSA course has been certified by the Illinois Law Enforcement Training and Standards Board, the Louisiana Stress Analyst Licensing Board and POST accepted in Tennessee, Georgia and Indiana. Other states are pending.

He has been an internal fraud investigator for over 43 years. He served as a sworn Special Depuy Sheriff as Truth Verification Examiner, Internal Affairs Investigator and special projects investigator. He is a Certified Forensic Hypnotist and a Certified Clinical PDD Examiner for Sex Offenders. (Post Conviction Sex offender Testing – PCSOT, qualified by the Florida Department of Corrections, Division of Community Control.

Baker has improved VSA science utilizing space-age technology, and techniques. He conducted VSA and Polygraph Certified Examiner Courses for Air Force Research Laboratory engineers and analysis specialists of the National Institute of Justice’s – Law Enforcement Analysis Facility and National Law Enforcement and Corrections Technology Center for their continuing VSA detection of deception validation studies. We believe that the AFRL positive results validate his VSA stress pattern quantification and chart interpretation procedures.

He served three 2-year terms as Trustee and Board Member of the Cocoa Beach (FL) Police Department Pension Board, a city commission appointment.


El Arte del Interrogatorio Cientifíco, (The Art of Scientific Interrogation)

Juan A. Benavides

ISBN: 978-970-95500-0-9

Monterrey, MX 2007

383 PAGES, Spanish

Mr. Juan Benavides has published the first complete study of all forms of scientific interrogation methods including a detailed history of VSA. This university quality textbook verifies  E. Gary Baker as a VSA pioneer, early developer of scientific VSA training and operations from the initial days of the Psychological Stress Evaluator through modern international uses. Baker is revealed as the formidable  marketer and instructor in Latin America. Version two of this unique and important textbook is nearing release.



MARVIN (BUD) McCORKLE, Chief of Police (Ret.)/Consultant, Indianapolis, IN.

Associate DVSA Instructor

With over 35 years of law enforcement and private security experience, Bud retired as Chief of Police, Ingalls, IN. He served 17 years as VP Loss Prevention, Paul Harris Stores, Inc., in charge of security operations for 500 retail operations in 38 states. An experienced PDD examiner utilizing polygraph since 1969, PSE since 1980, Lantern, and DVSA, he testifies as an expert witness in detection of deception examining. He prefers the DVSA system.

Bud is a Certified Analyst, Fellow, and “Life Member” currently serves as President of the International Society of Stress Analysts (ISSA) and Interim President of the American Polygraph and Voice Analysis Association (APAVSA).


RON KRAMER, Master Deputy Retired.

RON is a retired Florida certified Law Enforcement and Corrections Deputy having over 30+ years of law enforcement experience; (which includes: US Secret Service, Metro-Dade Public Safety and Director of Region VI, State of Indiana Criminal Justice). He has had operational experience in Special Operations and Uniform Division(s); also serving as point of contact / liaison for various foreign and federal agencies during visits of dignitaries. He was Senior Negotiator / (Team Leader), for the Indian River County Sheriff’s Hostage/Crisis response Team and holds a Federal Certification as an Instructor in First Response, Hostage/Crisis Negotiations. Ron served as one of the agency’s Tactical Flight Officers, was the Administrator of the Alarm Compliance Unit; and, for one year, was the Sheriff’s Office interim Public Affairs Officer.. Currently, Ron’s certifications include: National Association of Safety Professionals as an Emergency Management Specialist, (CEMS); Florida Attorney General as a Crime Prevention Practitioner, (CPP); the International Foundation of Protection Officers as a Certified Protection Officer, (CPO). He was also a Security Specialist / WMD-HAZMAT Technician for US Health & Human Service DMORT-WMD. While in Indiana, Ron was a certified rescue/recovery diver, an instructor/supervisor for Bloomington Hospital Ambulance Service and the interim Director of Warrick County Emergency Services. Ron continues to serve as a consultant in Operations Security and Threat Management for several corporations and is Assistant Director of Intelligence for UACT. He has practiced VSA since 1998 and prefers DVSA since its release.


NELSON SPRIGGS, Investigator and Certified Fraud Examiner, Fernandino Beach, FL

Nelson has over 20 years security and investigative experience including a tour in Vietnam as a company grade officer with the Security / Intelligence Department, U.S. Naval Support Activity, Da Nang. After graduating from the Combined Federal Law Enforcement Center in Washington, DC, he served with the US Park Police. He was in charge of security and audit management with two community banks conducting investigations of internal and external criminal activities. He served as a field grade officer (reserve mobilization augmentee), U.S. Air Force Office of Special Investigations.

Nelson is a trained polygraph, PSE, Lantern and DVSA examiner. He is a college instructor. He has practiced VSA since 1997 having formerly utilized PSE, Diogenes Lantern and since its release uses DVSA.


William Zumwalt, Sgt. Major, US Army (Ret.)

Associate DVSA Instructor

Bill currently provides private training and consulting services regarding security and protective topics throughout the Americas, Europe and Middle East. His private assignments have ranged from training security and executive protection personnel, provided security assessments, and intelligence briefings for major US corporations and foreign governments. He is an instructor in interview and interrogations. His Army assignments included: US Military Group, El Salvador, 1st Special Forces Operational Detachment, Delta, 5th Special Forces Group, and 1st Special Forces Group.

He is a polygraph, DVSA and FVAS  examiner and instructor. He represents The Baker Group in Latin America, Europe and middle east upon request. Mr. Zumwalt is fluent in the Spanish language and resides in Costa Rica. Since 1990 he utilized PSE, Mark II, FVSA and Diogenes Lantern VSA. Now he prefers DVSA.


Clifford Hopkins, Chief of Police (Ret.), former Senior LE Analyst, LEAF & NLECTC-NE.

After serving 27 years in various law enforcement positions Cliff retired as Chief of Police, Oneida, NY. He then served as Senior Law Enforcement Analyst at the Law Enforcement Analysis Facility (LEAF) – National Law Enforcement and Corrections Technology Center-Northeast Region (NLECTC-NE). a National Institute of Justice (NIJ) funded program. He provided law enforcement and correction agencies with technology assistance. He conducted briefings to end users and administrative level personnel on the development, evaluation and use of technologies including Voice Stress Analysis. He was Senior Analyst for the Air Force Research Laboratory, Rome, NY (AFRL) Evaluation of Voice Stress Analysis Technology, Phase 1 & 2, validating VSA and the Baker stress pattern quantifications and chart interpretation methods. He also conducted the Study of the Effects of Audio Corruption on Voice Stress Analyzer Results utilizing the Baker DVSA. His specialties include Audio & Video forensics, use of Voice Stress Analyzers, Database Development, and Photography.


Sarel Franscous Germishuizen – Former Detective Inspector, South African Police Service

Ex Detective Inspector South African Police Service,16 Years Police with the South African Police Service. Experienced Detective performing duties as an Investigator, Undercover Agent and Intelligence Officer. Certified VSA Examiner / Instructor. Founding member of the American Polygraph and Voice Stress Association (APAVSA) – South African Chapter. Currently Director at Vintotron Intelligent Risk Solutions specializing in VSA Testing and Training, Investigations, Surveillance and Counter Surveillance.


DWAYNE STANTON, Det. (Ret) Metropolitan Police Dept., Washington DC

Associate DVSA Instructor

Dwayne retired from the Metro DC Police Department’s Homicide Division where he was an investigator and training instructor, CVSA examiner / instructor, and interrogator. . He is certified as a VSA examiner / instructor utilizing CVSA, Lantern and DVSA.

A Legal Investigator since retirement he specializes in investigating major crimes, homicides and Organized Crime matters. His list of clientele is a “Who’s Who” in the modern criminal justice arena, from prestigious law firms and major corporations to high profile celebrities.

He has practiced VSA since 1992, utilizing CVSA, Diogenes Lantern and now prefers DVSA.


LAVELLE PITTS, Sheriff (Ret.) Bay County, FL

LAVELLE PITTS is a 40-year veteran of law enforcement and criminal investigations. He has served as Chief of Police, Florida State Deputy Fire Marshall, Florida Marine Patrol (Major) in charge of statewide anti-smuggling operations, and Special Agent for Florida Sheriff’s Bureau, Chief of Criminal Investigations, Chief of Detectives, and Sheriff of Bay County, FL.

For the past twenty years Pitts conducts legal investigations in the Florida panhandle specializing in criminal and civil investigations. He is a Certified Stress Analyst and is a Qualified Expert Witness in voice stress analysis.


MICHAEL W. SAVAGE, LT. COL. US ARMY (Ret), Guatemala, Colombia & El Salvador

Michael W. Savage is a retired Lt. Col. with extensive experience in Latin America and counter terrorism, serving in hot-spots such as Colombia and El Salvador and later as the J-3 Operations Officer for the reconstruction of Panama following the 1989 invasion. Earlier in his career he was the Assistant Operations Officer for the 1st Ranger Battalion when it was responsible for all counter-terrorism and hostage rescue operations for the United States prior to the establishment of the Delta Force. He later held the position of Civil-Military Affairs officer for the same unit, responsible for planning and liaison with foreign military and civilian governments worldwide. After retiring, he became associated with the Diogenes Company where he served as the Vice-President for Operations. After leaving Diogenes he now operates his own independent VSA firms in Guatemala, El Salvador, Colombia and Ecuador. He has provided VSA training and examinations in the U.S., Colombia, Mexico, Guatemala, El Salvador, Honduras, Ecuador and Peru. He has practiced VSA since 1997 utilizing Diogenes Lantern and now prefers Forensic Voice Analysis System (FVAS) of which EXPERTOSVSA, S.A. is the copyright owner.  He resides in Guatemala.


KIRK D. NELSON, Commander, (Ret.), Detective Division, Pocatello Police Department, Pocatello, ID.

Kirk retired after 32 years with the Pocatello Police Department. His last 13 years as Commander of the Detective Division, background investigation unit, VSA, polygraph unit and internal investigations unit. He has operated a private truth verification business for over 20 years administering over 3600 examinations including court ordered post conviction sex offender tests, custody evaluations and law enforcement pre-employment tests. He utilizes DVSA© and polygraph instrumentation in tandem (PolyStress™) and independently. Currently he serves as a special investigator for the Idaho Department of Law Enforcement POST Academy, Office of Professional Responsibility. His duties include conducting officer de-certification investigations. Kirk earned a BS degree from Idaho State University and is a FBI National Academy graduate. He is a member of Academy of Certified Polygraphists, Idaho Polygraph Association, Northwest Polygraph Examiner’s Association and American Polygraph and Voice Stress Association. In 2005 Kirk became a certified DVSA© examiner.