John served for over 20 years with the City of Dover Police Department in Delaware, retiring with the rank of Captain. During his police service he was a police firearms instructor and an active PPC competitor, twice winning the title PPC State Champion and a multi-time member of Delaware’s Governors Twenty. He was a member and eventually captain of the Dover Police Pistol Team, competing in Conventional Pistol, Air Pistol and Free Pistol tournaments in addition to Police Combat Pistol. He served on and eventually commanded Dover’s "Barricade Team" (SWAT). In addition to being a long-time NRA referee at Camp Perry and the NRA’s police nationals, John is now an NRA High Power and F-Class competitor and competes regularly with his wife, and shooting partner, Ingrid Sigler, shooting sporting clays tournaments throughout the Delmarva region.

John was the co-founder and founding president of the Delaware Law Enforcement Marksmanship Association, member of the Board of Directors of the Delaware State Sportsmen’s Association and a founding member, Board member and chief lobbyist for the Delaware Foundation for legislative Action. John is a member of the Board of Directors of the National Rifle Association of America, being first elected to that Board in 1996 and serving continuously to the present. He served two terms as NRA’s 59th President and is a member of that organization’s Executive Council.

John is an experienced political operative having served as finance chairman, campaign chairman and political advisor to numerous political candidates. He is the past-Chairman of Delaware’s 34th District Republican Committee, past member of the Executive Committee of the Republican Party of the State of Delaware, and past chairman of the Kent County, Delaware Republican Committee. Although John’s interest in "The .50’s" is mostly political and philosophical, John has competed in the FCSA World Championships. It should also be noted that his wife Ingrid’s first experience in shooting any rifle of any kind was shooting a .50 BMG "heavy gun" in Reno, NV during FSI’s open house for the NRA Board of Directors.