Sergeant Dunne served as a U.S. Marine before his 27 year police career. He served as a SWAT Officer and sniper for 8 years, and also a full time academy instructor for 8 years. He is highly decorated, to include the Police Medal of Honor, the Distinguished Service Cross, and multiple life-saving awards. He has been a pistol, rifle, and shotgun instructor since 1999, and has taught firearms, self-defense, active shooter response, and many other subjects, to thousands of civilians and Law Enforcement nationally. Sergeant Dunne was a lead firearms and combatives instructor for the Steel Curtain contract, client: U.S. Intelligence. Sergeant Dunne is certified as an expert witness in federal court in firearms, edged weapons, & self-defense. He has competed as both an amateur and professional in MMA, boxing, and kickboxing, and has been shooting competitively for over 20 years. Sergeant Dunne founded Ragnar Tactical in 2002, and teaches virtually every week, year round.