Capt Grimes is a native Texan. In May 2014, he graduated from Texas A&M University in College Station, TX with a Bachelor of Science in Leadership Studies and commissioned as a Second Lieutenant. Following IOC 1-15, he was assigned to 1st Light Armored Reconnaissance Battalion in December 2015. At 1stLAR, he served as Company Executive Officer for Charlie Company. From July 2017 to February 2018, First Lieutenant Grimes deployed on the 15th MEU with BLT 1/5. While deployed he was sent to Task Force Arabian Peninsula in Bahrain, where he was sent into Saudi Arabia with a small team to advise the Saudi Military on aerial reconnaissance and aerial strike operations.
Upon return from the MEU First Lieutenant Grimes began his transition out of active duty, officially departing July of 2018. In October 2018, 1stLt Grimes joined Marine Forces Reserve and began serving as Company Executive Officer for Charlie Company 4th LAR and was promoted to Captain in November 2018. From October of 2018 to December 2021 Capt Grimes served as Company Executive Officer.
In January of 2022 Capt Grimes transferred to Weapons Company 1/23 where he is currently served as the Executive Officer until August 2024, when he was given the opportunity to serve as the Commanding Officer.
His personal awards include the Navy and Marine Corps Achievement Medal, the Joint Service Achievement Medal, and the Navy Meritorious Unit Commendation Medal.