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.

Management & Board of Advisers

E. Gary Baker, PhD, Director and Founder

Inventor/Developer of Digital Voice Stress Analysis (DVSA)

E. Gary Baker, 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, longer than any competitor. He worked closely with the three inventors of VSA and participated in validation studies. Col. Charles McQuiston was a mentor. The International Society of Stress Analysts (ISSA) 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 & Deception  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 Indiana Law Enforcement Board, the Louisiana Stress Analyst Licensing Board and POST accepted as “in-service” training.

He has been an internal fraud investigator for over 48 years. He served as a sworn Special Deputy Sheriff as Truth Verification Examiner, Internal Affairs Investigator and special projects investigator. He is a Certified Forensic Hypnotist and a Certified Instructor & Clinical PDD Examiner for Sex Offenders. (Post Conviction Sex offender Testing – PCSOT, qualified by the Florida Department of Corrections, Division of Community Control.)  He is also a PCSOT instructor for PolyStress examinations.

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 accuracy results of 100% validate his VSA stress pattern quantification and chart interpretation procedures.  See USAF Rome Labs VSA study Phase One and Two.

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

Textbook About E. Gary Baker & DVSA

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 instructor. Version two of this unique and important textbook is nearing release.


Dwayne A. Stanton, Associate Director

Detective (Ret), D.C. Metro Police Department, Homicide Div., Washington DC.

Professional Experience

NBC Universal / Peacock Productions, September 2017 – Present

Co-Host of an Unscripted National Syndicated Crime Show, The Disappearance of Crystal Rogers, which is a six-episode Homicide Investigation of a Mother of five, her Father, and an off-duty Police Officer in Bardstown Kentucky. The series received the highest ratings in its time slot in a three year period on the Oxygen Network.  

The National Center for Missing And Exploited Children, Case Manager July 2016 – September 2017

As primary point of contact for missing children’s cases, I handle cases from start to recovery. I engage in communication with law enforcement and the families of missing children to obtain pertinent details.  I evaluate each case’s severity to include high-risk behavior patterns and provide all resources applicable to recovery, to include media outlets and deployments.

I take care to cultivate a positive working relationship with all parties of each case to include parents, guardians and law enforcement personnel in order to encourage communication in an effort to obtain as much detail as possible leading to recovery.  I also provide any technical assistance needed to invested parties and other authorized agencies on domestic and international resources in a timely fashion.

The National Center for Missing, And Exploited Children, Team Adam Consultant / Project Alert Volunteer, March 2015 – July 2016 / September 2017 – Present 

As a member of “Team Adam”, I provide rapid on-site assistance to law enforcement agencies and families in critical cases of missing children.  Upon availability, this team deploys to sites where these cases are unfolding and provide on-the ground technical assistance and connect law enforcement agencies to a national network of resources.

AlliedBarton Security Services, Account Manager/Operations Manager, December 2011-February 2015

In these positions I have managed Major Accounts that have ranged from 500 hours to over 2,800 hours weekly, and manage approximately 80 Staff Members, to include 3 Assistants, this includes administrative matters, training, and proper staffing.  I was responsible for all aspects of life and safety issues for trophy class properties, as well as Institutions of Higher Learning.  This includes vulnerability assessments, access control, proper CCTV coverage and monitoring to name a few.

I managed over 900 Officers at the 2012 Democratic National Convention in Charlotte, North Carolina. Also, I was the Security Director of a local Mall, which was one million square feet in size, with over one hundred fifteen retail outlets. I am a Certified CPR Instructor and a Notary Public for the District of Columbia as well as for the State of Maryland.

Lincoln Property Company, Director of Security/ Building Services, January 2002 -December 2011

In the position I was responsible for ensuring the safety and security of the company’s employees, vendors, tenants and guests.  I also served as a security consultant for the 20 million square feet of property the company manages and/or owns. Further, my overall responsibilities included development and implementation of security policies and procedures, access control, as well as executive and dignitary protection.  I conducted investigations involving a multitude of issues and violations of the law.  Further, I managed a comprehensive access control/physical security system.  I also developed and managed security awareness training and education strategy. I managed a budget of approximately one million dollars, and also coordinated with the U.S. Secret Service, and other Law Enforcement agencies to deliver a safe and secure 2009 Inauguration of the President of the United States.  I have successfully planned and executed a number of VIP Visits of Heads of State, as well as both previous and present Vice Presidents of the United States.

Progressive Security Consultants, LLC., President/Director, 1995-Present

I manage a team of consultants that provide professional security and consultant services, that include but are not limited to investigations, background inquires, electronic surveillance, voice stress analysis, personal protection, physical security, process service and loss prevention. Also, in this position I appeared on the NBC Dateline Television Show entitled, Homicide, the Unsolved Case Squad.  I offered professional and expert investigative opinions, and analysis on various homicide cases that have occurred across the country.   I also am an on air contributor for MSNBC on high profile criminal cases, and was the Lead (Private) Investigator on the Chandra Levy investigation.

Metropolitan Police Department, Washington DC, Training Director; Criminal Investigation Division, October 1994 – April 1999

In this position I was responsible for the development and implementation of a full curriculum of Criminal Investigator Training for the entire Criminal Investigation Division which consisted of approximately 300 members.  Areas of concentration included but were not limited to homicide and death investigations, sex offenses, robbery and fraud investigations. I instructed as well as coordinated with other instructors for in-house as well as outside training.

Metropolitan Police Department, Washington DC, Detective Grade One; Homicide Branch, June 1994 (Promotion)

I held the senior level supervisory investigative position.  Responsibilities included the examination, review and coordination of subordinate detectives’ cases.  I would critique and review numerous cases surrounding homicide investigations, ensuring that proper police procedures and techniques were followed and utilized.  I was also responsible for ensuring cases were prepared for court presentation, inclusive of affidavit reviews, warrant reviews and proper criminal evidence preservation.

Investigator/Detective Grade Two; Homicide Branch, Federal Bureau of Investigation, February 1983 – February 1994

In this position I investigated deaths that fell under the umbrella of the Office of the Medical Examiner.  Those deaths included homicides, suicides, accidental, industrial and fire deaths.  I also handled other natural but unattended deaths.  I worked closely with outside agencies such as OSHA, FEMA and the M.P.D.C. Mobile Crime Laboratory in the collection of evidence and consulted with the M.P.D.C. Firearms and Fingerprint Examination Sections, as well as the F.B.I. Forensic Laboratories in the analysis of evidence.  Further, I assisted the U.S. Attorney’s Office for the District of Columbia in the prosecution of the alleged perpetrators of these crimes.  I functioned as the prosecutors’ primary assistant, locating and interviewing witnesses.  I managed the collection of physical evidence and assisted in the preparation of witnesses to testify as well as testifying at the subsequent judicial proceedings.  I was the primary Detective in approximately 1000 deaths and investigated over 750 homicides with a 92 percent success rate.

Military Service:

I served in the United States Army, 1976 until 1980 in the Military Police Corps and received an Honorable Discharge.

Education and Training:

Laboratory for Scientific Content Analysis    SCAN Analyzer

F.B.I. Academy      Interview and Interrogation (Basic and Advanced)

F.B.I. Academy      Death and Homicide Investigations (Basic and Advanced)


Chief Jody O’Guinn, Director – Law Enforcement Operations

Jody O’Guinn is a retired police chief from Carbondale, Illinois. Beginning his law enforcement career in 1983 as a patrol officer for the Freeburg, Illinois Police Department, he transitioned to the Alton, Illinois Police Department in 1987.  During his tenure at the Alton Police Department, Jody was fortunate to hold a variety of positions and gain valuable experience as a field training officer, detective, traffic officer, SWAT team member, Sniper team leader, and undercover narcotics officer for the Alton Police Department, State Task Force and the DEA Task Force.  Jody was also the SWAT team commander for the Alton Police Department and commanded a Regional WMD Special Response Team through the Illinois Law Enforcement Alarm System (ILEAS). Promoted through the ranks, Jody retired from the Alton Police Department at the rank of Deputy Chief in 2009. In 2009 Jody accepted the position of Police Chief for the Carbondale, Illinois Police Department, leaving there in 2014 to pursue other ventures. He has extensive tactical experience and training and has held several positions on regulatory, training and policy boards within the State of Illinois.  His latest board appointment was by the Governor of the State of Illinois to the Taser and Use of Force Advisory Committee.

Jody is currently the Vice President and Chief Academic Officer for the McAfee Institute and an Adjunct Professor for Missouri Baptist University. He has been an adjunct faculty member for Lewis & Clark Community College, John A. Logan College, Southern Illinois University and the Department of Homeland Security.  Jody holds instructor status for numerous disciplines including firearms instruction, use of force instruction, NIMS, Weapons of Mass Destruction General Instruction and other various law enforcement areas of instruction.

Jody is a native Illinoisan, now currently residing in Missouri, has a full head of hair and knows his way around a nice box of red wine. He graduated college with a GPA sitting in the meaty part of the bell curve, not lagging behind, but not trying to show off either. Jody is an avid outdoorsman and enjoys traveling, camping, shooting sports, and riding his Harley. Golf is his game now. He’s long off the tee but can’t putt worth a damn.  Education & Credentials-CCFI:  Certified Cryptocurrency Forensic Investigator – McAfee Institute (2018, ),LEEDS: FBI Academy (2010),FBINA: Graduate of 223rd Session (2005 ,  M..P.A., (Public Administration & Policy Analysis), Southern Illinois University, Edwardsville, IL (2002),B.S., (Police Science) Sterling University, Sterling KS (1998),  A.A.S., (Criminal Justice) Lewis & Clark Community College, Godfrey, IL (1996).  He has been a DVSA Examiner since 2014.

Board of Advisers

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 (Ret.), Indian River County Sheriff’s Office, FL

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, Brunswick, GA

Nelson has over 30 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 and DVSA 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

Former Detective Inspector, South African Police Service. 16 years 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.


Lavelle Pitts, Sheriff (Ret.) Bay County, FL

LaVelle passed away in November 2019 from complications of COPD.  He was a close friend and mentor. RIP my friend. 

LAVELLE PITTS was a 40-year veteran of law enforcement and criminal investigations. He 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 conducted legal investigations in the Florida panhandle specializing in criminal and civil investigations. He was a Certified Stress Analyst and a Qualified Expert Witness in DVSA 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 operated his own independent VSA firms in Guatemala, El Salvador, Colombia and Ecuador. He has provided VSA training and examinations in  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).  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.