All instructors and assistants teaching with DTG have extensive certifications, training and teaching experience in a variety of martial arts, law enforcement or military environments; many have practical law enforcement and military experience as well.

The chief instructor, Roland Berg, has completed certification programs as a stressfire instructor through Massad Ayoob’s Lethal Force Institute and a defensive tactics instructor through Modern Warrior.  He is  holds certificates as a  Law Enforcement Instructor, Law Enforcement Firearms Instructor, and Master Peace Officer in the state of Texas.

He trained in, and taught,  Wing Tsun Kung Fu and has completed training in Judicious use of Deadly Force, Stressfire Instructor, Lethal Threat Management for Law Enforcement, Persuader Self-Defense Keychain, Advanced Handgun Skills, and Jim Cirillo’s Close Quarter Firearms.  He has also attended conferences and seminars of the American Society of Law Enforcement Trainers.  

He is a Commissioned Peace Officer, serving over 15 years, and he has taught Use of Force, High Risk Patrol Tactics, Contact and Cover, Basic Street Level Narcotics Enforcement, Stressfire, and various other topics.