Major St. John reported to Officer Candidate School, Quantico, Virginia in May 2011. He graduated from the University of Missouri in May 2012 and commissioned as a Second Lieutenant. In November 2012, Second Lieutenant St. John reported to The Basic School, Quantico, Virginia and completed the Basic Officer Course. In September of 2013, Second Lieutenant St. John completed the Infantry Officer Course.
Upon graduation from Infantry Officer Course, Second Lieutenant St. John reported to 1st Battalion, 1st Marines in Camp Pendleton, California and served as a Rifle Platoon Commander deploying on Unit Deployment Program-W in 2014 where he participated in Exercise COBRA GOLD and was promoted to First Lieutenant. While deployed, First Lieutenant St. John transitioned to the Company Executive Officer billet and served in that capacity through the end of his second deployment in 2016: Marine Rotational Force-Darwin.
First Lieutenant St. John was promoted to Captain in January of 2017 and reported to Naval Amphibious Task Force 51/5 in Manama, Bahrain. Captain St. John served as a Current Operations Officer and Liaison Officer to the Western Yemen Fusion Cell, working alongside the Emirati Presidential Guard. Captain St. John transitioned from active-duty in May 2018.
In April 2019, Captain St. John affiliated as a drilling reservist to 3rd Battalion 23rd Marines, serving as the Assistant Operations Officer. In January 2020, Captain St. John conducting an Inter-Unit Transfer to 1st Battalion 24th Marines, serving as a Rifle Platoon Commander until mobilization and deployment as a Foreign Military Advisor as a part of Georgia Liaison Team ROTO-12. After training alongside the Georgian Army for two months, Captain St. John and his team were re-missioned to facilitate operations in the Kingdom of Jordan as a part of Security Cooperation Team- Jordan 21.2.
Upon demobilization and redeployment, Captain St. John reported to the III Marine Expeditionary Force Individual Mobilization Augment Detachment, serving as a Senior Watch Officer aboard Camp Courtney, Okinawa in February 2022. Promoted in May 2023, Major St. John transferred to Bravo Company 1st Battalion 24th Marines in Terre Haute, Indiana to serve as Company Commander in September 2023.
Major St. John's decorations include the Navy and Marine Corps Commendation Medal and the Navy and Marine Corps Achievement Medal with gold star in lieu of second award.
Major St. John has multiple bachelor's degrees from the University of Missouri-Columbia and is currently pursuing a Masters in Business Administration from Washington University-St. Louis. In his civilian career, Major St. John is the Director of Operations for an HVAC, electric, plumbing, and appliance company in Missouri.