Lieutenant Colonel McCarthy was commissioned in 1998 after graduating from the University of Dayton. As a Lieutenant, he served with 2d Battalion, 8th Marines where he deployed as part of the 24th Marine Expeditionary Unit (Special Operations Capable) in 2001. As a Captain, he served with the Chemical Biological Incident Response Force, 4th Marine Expeditionary Brigade (Anti-Terrorism), where he deployed in support of OPERATION IRAQI FREEDOM-I in 2003. There, he also took part in the response to the Ricin attack on the U.S. Capitol in 2004.
LtCol McCarthy left active duty in 2004 to attend law school. While in law school, Capt. McCarthy joined 3d Battalion, 25th Marines where he initially served as a rifle platoon commander and executive officer of Company L. From 2005 – 2008, he commanded Weapons Company and served as the Battalion Fire Support Coordinator.
Following company command and promotion, Maj McCarthy served as a USMC Congressional Fellow. He returned to active duty from 2008 – 2010 to serve as the Military Legislative Assistant to the Chairman of the House Intelligence Committee.
Maj McCarthy joined the staff of the 22d Marine Expeditionary Unit in 2010. He was mobilized in 2011 - 2012 as the Future Operations Officer and completed a 10+ month deployment in support of several named operations in the 5th and 6th Fleet AORs. Upon return, Maj McCarthy joined 4th Air Naval Gunfire Liaison Company where he served as the Operations Officer until 2014. He then joined 4th Light Armored Reconnaissance Battalion and served as Executive Officer until assuming his current command.
LtCol McCarthy is a graduate of the Marine Corps Command and Staff College (non-resident) and the Amphibious Warfare School (non-resident).
His personal decorations include the Navy and Marine Corps Commendation Medal with three gold stars and the Navy and Marine Corps Achievement Medal. He is authorized to wear the Navy and Marine Corps Parachutist Insignia.
In civilian life, LtCol McCarthy is the managing member of a law firm. He is also a principal in a consulting practice that advises other attorneys on military issues.