Lieutenant Colonel DeTrinis is from New Orleans, Louisiana. He received his commission in 2002 via the Platoon Leaders Course following graduation from Delta State University. His operational assignments include Platoon Commander and Company Executive Officer, 1st Battalion, 2d Marines; Platoon Commander, 2d Reconnaissance Battalion; Team Commander and Company Executive Officer, 1st Marine Special Operations Battalion; and Operations Officer, 2d Battalion, 2d Marines. He deployed in support of Operation IRAQI FREEDOM, Operation ENDURING FREEDOM-Afghanistan, and SPMAGTF-CR-AF/Black Sea Rotational Force.
Other assignments include Officer in Charge, Special Operations Training Company, Marine Special Operations School, and Regional Planner and Plans Officer, III MEF G-5.
He is a graduate of Expeditionary Warfare School (Non-resident), Command and Staff College CDET (with distinction), Command and Staff College (with distinction), and the School of Advanced Warfighting. He holds a Masters in Military Studies and a Masters in Operational Studies from Marine Corps University and received the Colonel Franklin Brooke Nihart Award from Command and Staff College.