Training Solutions for High Threat Environments

About Us

SERT Group International was started in 1991 and serves our home communities surrounding Los Angeles, California, as well as the rest of our great nation, providing self-defense courses for individuals, and members of the military and law enforcement. We are a Department of Defense registered contractor. Our outstanding reputation among professionals worldwide is a direct reflection of our training staff. We are highly skilled individuals who come from various communities including the military, law enforcement, tactical medical, combative arts, and private security. Our cadre is made up of subject matter experts in their respective disciplines.

Most of our adjunct and guest instructors are currently active in their various specialties, and remain at the cutting edge of their fields of expertise. We are committed to providing you with the highest level of professionalism, enhancing your operational capabilities, and supporting your team's effectiveness.

Scott Sheldon – President/Director of Training

Scott Sheldon

Scott is the founder and training director of SERT Group International. He has been teaching tactical medical and firearms courses to individuals and units from the United States military, and federal, state, and local law enforcement agencies for more than 10 years. Scott is a licensed paramedic and has extensive experience in tactical, austere, and air rescue operations. He was instrumental in developing the tactical medical program for the Ventura County Sheriff's Department where he served as the medical team leader and lead TEMS instructor.

His responsibilities included entry and rescue team medic, operational medical planning, threat assessment, and providing immediate medical care during all operations and trainings. He participated in numerous VIP protective support details including Operation Sundown, the funeral for President Ronald Reagan, Israeli Prime Minister Menachem Begin's visit to the Ronald Reagan Presidential Library, and Presidential candidate George McGovern's trip to Ventura County.

Scott has trained and worked with personnel from various law enforcement and military Special Operations communities. Prior to Operation Iraqi Freedom he trained the King of Jordan's Personal Protective Unit's tactical medical team. Scott is a frequent lecturer, speaking at various law enforcement and military conferences around the country, including the prestigious Special Operations Medical Association. He has authored numerous articles for tactical publications and appeared in the "Street Smarts" DVD series.


• Tactical Paramedic - VCSD SWAT
• Tactical Trauma Care - Advanced SWAT School Instructor
• NRA Certified Pistol - Instructor
• Krav Maga - Black Belt/Instructor
• Flight/Rescue Paramedic - VCSD SAR Team 6
• Training officer - VCSD SAR Team 6
• Defensive Tactics Institute - TEMS Instructor
• Daniel Freeman Paramedic School - Instructor
• ACLS/PALS - Instructor
• HK Tactical Emergency Medicine
• Operations and Planning for WMD
• Basic and Advanced Combat Pistol
• Israeli Combat Shooting School
• Hostage Rescue Techniques
• Edged Weapons
• Defensive Tactics

Nathan Carlin – Combative and Edged Weapons Instructor

Nathan is a highly respected Martial Arts instructor. He holds a 5th-Degree Black Belt in American Tang Soo Do and was the13th person to earn Masters Ranking within the American Tang So Do Alliance. Nathan is also an accomplished instructor in edged and blunt weapons as well as Krav Maga. He is a college professor teaching Physical Education and Martial Arts. Nathan has taught numerous self-defense seminars for military and law enforcement personnel, as well as civilians. He has worked as a Personal Security Specialist and is the lead safety instructor for the SMART Leadership program.


• 5th-Degree Black Belt in American Tang Soo Do
• Licensed Instructor in Krav Maga
• Instructor Ranking in Kali/Silat Systems of America
• Instructor in Brazilian Jiu-Jitsu
• 2nd-Degree Black Belt in Shorin Ryu/Shotokan Karate
• 1st-Degree Black Belt in Jiu-Jitsu
• 1st-Degree Black Belt in Hapkido
• Member of Martial Arts Industry Association
• Adjunct Instructor - L.A. Mission College
• Professor - L.A. Pierce College

George Liao – Cadre Firearms and Combatives Instructor/RSO

George Liao

George is an NRA-certified Range Safety Officer and is our range operations tech. He had extensive firearms experience before joining us and is a valuable addition to our shooting programs. He is also a Defensive Tactics/Combatives instructor and holds a black belt in Krav Maga.

Ralph Rendina – Cadre Firearms and Combatives Instructor/NRA Pistol Instructor/RSO

Ralph has been a competitive shooter since he was 16 years old. He has and still competes in Bullseye Pistol, IDPA, International Handgun Silhouette, Precision Rifle, and Long Range Rifle Silhouette competitions. He is an NRA-certified Pistol Instructor and Range Safety Officer. Ralph holds a red belt in Tang Soo Do and is a brown belt in Krav Maga.

Ralph Rendina

Steven Tritt - East Coast Division Manager

Steven Tritt

Steven will be conducting our courses from his home base in Florida. He brings a variety of experience and skills sets to the company. Steven has over 12 years of experience, deploying to combat theaters both in the U.S. Navy and as a civilian contractor working in personal protection as an operator / instructor.

His areas of expertise and instruction include: C.Q.B, firearms, hand-to-hand combat, knife and stick fighting, and less lethal munitions. He has extensive experience teaching military and law enforcement personnel in both firearms and combatives.