Lieutenant Colonel Keith Cassidy graduated from Marine Corps Officer Candidates School and was commissioned a Second Lieutenant on March 20, 2009. He then attended The Basic School where he was awarded Active Duty Career Designation and received the Iron Mike Award, before reporting to the Infantry Officer Course (IOC). Following IOC, Lieutenant Cassidy reported to Light Armored Vehicle Training Company, Advanced Infantry Training Battalion, School of Infantry West where he completed Light Armored Reconnaissance Leaders Course graduating as the Distinguished Honor Graduate of Class 2-10.
Upon conclusion of training in 2010, Lieutenant Cassidy was released from active duty to report to Company D, 4th Light Armored Reconnaissance Battalion. From February 2010 to April 2012, he served as platoon commander for 3D Platoon. During this time, he participated in OPERATION SHARED ACCORD conducting combined arms training in the Republic of South Africa. In May 2012 Lieutenant Cassidy was mobilized in support of OPERATION ENDURING FREEDOM deploying initially to MARCENT FWD (NSA Bahrain) as a G3 Senior Watch Officer. In October 2012 Lieutenant Cassidy was transferred to Amman, Jordan to serve as Deputy Officer in Charge of the Jordanian Operational Deployment Program and was promoted to Captain. Serving out of the US Embassy Amman from October 2012 until his redeployment in May 2013 Captain Cassidy facilitated training for over one thousand members of the Jordanian Armed Forces who subsequently deployed to Afghanistan to serve in a partnered role with US forces.
Following his return from Jordan, Captain Cassidy transferred to Company B, 4th Reconnaissance Battalion where he served as reconnaissance platoon commander for 2D platoon and the Officer in Charge of the Reconnaissance Indoctrination Platoon from November 2013 until April 2015. From May 2015 until October 2017 Major Cassidy served as the Operational Liaison Officer for Company B, planning and overseeing the company's successful participation in Integrated Tactical Exercise (ITX) 4-15 and the pre-deployment training of the Battalion's first Unit Deployment Program (UDP) platoon. In November 2017 Captain Cassidy was frocked a Major and took command of Company B, a position which he held until November 2019. During that time the Company successfully completed Mountain Exercise (MTX) 4-18 and reintegrated its UDP platoon.
Upon relinquishing company command, Major Cassidy reported to Task Force Southwest to deploy to Helmand, Afghanistan as part of OPERATION RESOLUTE SUPPORT in February 2020. For the first five months of the deployment Major Cassidy served as the Director of Regional Targeting Team South (FWD) with a dual reporting chain to the Commander of Task Force Southwest and the Commander of NATO Special Operations Component Command Afghanistan (NSOCC-A) conducting crisis response, intelligence fusion, and deliberate and dynamic targeting. Following the draw down of forces, Major Cassidy transitioned RTT-S(FWD) to ODA 7325 and assumed the roles of Task Force Southwest's Director of Plans (J-5) and as a TF Joint Terminal Attack Controller (JTAC). Upon redeployment in November 2020, Major Cassidy returned to 4th Reconnaissance Battalion as the Battalion Training Officer, a position he held until November 2021. Major Cassidy then transitioned to become the SMCR Operations Officer for the Battalion, a position he held until December 2022. Subsequently, Major Cassidy was named the Battalion Executive Officer serving in the billet until March 2024. He was then promoted to Lieutenant Colonel and assumed command of 4th Reconnaissance Battalion in April 2024.
His personal awards include the Bronze Star Medal, the Navy and Marine Corps Commendation Medal with Gold Star, the Navy and Marine Corps Achievement Medal, and various other Service and Campaign medals. He was named Officer Honor Graduate of his Basic Airborne Course and Honor Graduate of Tactical Air Control Party Class 4-17. He is an Operations Tactics Instructor, JTAC instructor and a graduate of the Multi-Mission Parachute Course.
Lieutenant Colonel Cassidy holds a Bachelor of Arts in History from the University of Virginia, a Juris Doctorate from the George Washington University Law School and a Masters of Legal Letters in Securities and Financial Regulation from the Georgetown Law Center. He is licensed to practice law in the District of Columbia and the Commonwealth of Virginia and is a Certified Information System Security Professional (CISSP). In his civilian career, he is currently Deputy Director of the Division of Examinations at the US Securities and Exchange Commission and the agency’s Federal Senior Intelligence Coordinator (FSIC).