Sentinel Defense is a collaboration of two experienced, well rounded firearms instructors in their own right who have combined over 7 decades of real world police and military experience. We offer sound well vetted instructional techniques designed to teach the firearms operator proper manipulations and marksmanship with a real world combat mindset. Come train with us, bring a willingness to learn and let us take you to the next level.


Marc Fleischmann has over 40 years of law enforcement experience and has spent the majority of his career working specialized units as a tactical surveillance operator. Marc worked years as both an operator and finally a Supervisor and Firearms Instructor with the Los Angeles Police Department’s elite Special Investigation Section (SIS).

After retiring from SIS in 2007, Marc continued his law enforcement career as an Investigator with the Orange County District Attorney’s Office, Bureau of Investigation, working in an undercover capacity as a tactical leader of the Orange County Auto Theft Task Force (OCATT). In his current assignment, Marc was selected as the Range Master for his agency and Team Leader of the Dignitary Protection Team (DPT).

Marc has been a civilian and police firearms instructor for 33 years with numerous firearms instructor certifications from the NRA, Los Angeles Police Department, California Peace Officer Standards and Training (POST), FBI Firearms Instructor School as well as Sig Sauer. Marc has instructed at many recognized schools throughout the country as well as abroad. Marc has been a guest instructor at the Sig Sauer Academy and is a certified Sage Dynamics Miniature Red Dot Sight (MRDS) instructor and has trained with the Modern Samurai Project. Marc teaches at FBI Firearms Instructor School, the FBI Car Stop School and is a Colt AR15/M16 Certified Armorer and a Glock Master Armorer.

Marc is a Los Angeles Fire Department West Point Leadership Academy instructor.

Marc regularly competes in USPSA and IDPA matches


Clint Achziger is currently a Police Sergeant assigned to patrol for a large municipal police agency in Orange County, California. Clint has 29 years of experience as a full-time sworn Peace Officer, working mostly in specialized units. Previously, He spent four years with the Sonoma County Sheriff’s Department and eight years with the Los Angeles Police Department.

Clint has over 20 years of Firearms Instructor experience as a Firearms Instructor for all three agencies. Clint has Firearms Instructor credentials from the Los Angeles Police Department, Sonoma County Sheriff’s Department, San Diego County Sheriff’s Department, and the Federal Bureau of Investigation, all California Peace Officer Standards and Training (POST) certified instructor courses. Clint is an adjunct instructor at the Gunsite Academy in Paulden, AZ, a certified Sig Sauer Academy, Master Pistol & Master Rifle instructor, a certified Sage Dynamics Miniature Red Dot Sight (MRDS) instructor, and has trained with Modern Samurai Project.

Clint’s prior assignments have been: Firearms & Tactics Training Coordinator, Homicide and Gang Detective, SWAT Team member, Patrol Officer and Armorer. At his previous agencies, his assignments have been: Multi-Agency Gang Enforcement Team (MAGNET), Patrol Deputy, Community Resources Against Street Hoodlums (CRASH) as a Gang Officer and Gang Detective, Special Problems Unit (SPU), Patrol Officer, and has worked various other violent crime taskforces.

Clint is a United States Marine Corps veteran and deployed to the Persian Gulf for Operation Desert Shield / Desert Storm.

Clint regularly competes in USPSA and IDPA matches.