Benner has trained thousands of law enforcement personnel since founding TDI in 1986. Prior to that time he served as Lieutenant of the Village of Fairfax Police Department, Coordinator of the Drug Abuse Reduction Task Force, and Tactical Field Commander of the Hamilton County Police Association Special Weapons and Tactics Team (S.W.A.T.). John has developed courses for raid tactics, tactical weapons instructor schools, defensive tactics and knife programs that are currently taught to law enforcement, military and civilian groups.