Dr. Chassels was a merit badge counselor and lifeguard at the Pine Hill Scout Reservation from 1986-1990 where he taught wilderness survival and aquatic skills. He earned the Eagle Scout rank in 1988. It was through the Boy Scouts that Dr Chassels learned about firearm safety and proficiency.

He continued to refine his handgun proficiency while working for the Cherry Hill Department of Police, Division of Emergency Medical Services from 1990 through 1999 as an Emergency Medical Technician. Handgun shooting was a common recreation among squad members.

He graduated from Rutgers University with a Bachelor of Arts degree in 1993 and from Rowan University with a Master of Science in Teaching degree in 1995. He taught high school math and sciences for several years before thruhiking the 2160 mile Appalachian Trail in 1999.

In 2004, he earned his doctorate from AT Still University of Health Sciences in Kirksville, MIssouri. In 2007, he completed an internal medicine residency in Creve Coeur, Missouri. Dr. Chassels is board certified in internal medicine and has been practicing medicine in several emergency departments in southern Illinois for the last decade.

Dr Chassels believes we are all safer when law abiding citizens are well trained and armed. For this reason, he teaches concealed carry classes to the public. Dr. Chassels is certified by the Illinois State Police to teach Illinois Concealed Carry Classes. He is certified by the Utah Bureau of Criminal Identification to teach Utah Concealed Carry Classes.

He is certified by the National Rifle Association as a Training Counselor, Pistol Coach, and Instructor of the following classes:
Concealed Carry Weapons Course,
Advanced Personal Protection Outside the Home,
Basics of Personal Protection Outside the Home,
Personal Protection in the Home,
Defensive Pistol,
Chief Range Safety Officer,
Range Safety Officer,
Refuse to be a Victim,
Basics of Pistol Shooting,
Basics of Rifle Shooting,
Basics of Shotgun Shooting,
Pistol Marksmanship Simulator,
Basic Metallic Cartridge Reloading,
Basic Shotgun Shell Reloading.

He is certified by the United States Concealed Carry Association as a Training Counselor of Concealed Carry and Home Defense Fundamentals and as an instructor of:
Concealed Carry & Home Defense Fundamentals,
Countering The Mass Shooter Threat,
Emergency First Aid Fundamentals,
Women’s Handgun & Self-Defense Fundamentals,
Defensive Shooting Fundamentals.

Dr. Chassels has been certified by Massad Ayoob through his 40 hour immersion course, MAG-40.

Dr. Chassels is a life member of the NRA, Elite Member of the USCCA, Life Member of the Illinois Rifle Association, member of the Armed Citizens Defense Network, Life Member of the Second Amendment Foundation, Member of Doctors for Responsible Gun Ownership, and Managing Member of Chassels Family Gun Club, LLC.