Sergeant Major Sandlin was born in Cincinnati, Ohio and graduated from Mount Healthy High School in June of 2003. He enlisted in the Marine Corps in September of 2004 and was introduced to the recruit training process at Marine Corps Recruit Depot, Parris Island, South Carolina. Upon completion of Recruit training Sergeant Major Sandlin then reported to the School of Infantry, Camp Geiger North Carolina where he completed Marine Combat Training. After Marine Combat Training, Sergeant Major Sandlin attended the Nuclear Biological and Chemical Specialist School at Fort Leonard Wood, Missouri. Upon completion of school in May of 2005, he was then assigned to Headquarters Battalion, 2nd Marine Division, Camp Lejeune, North Carolina. Sergeant Major Sandlin was sent on temporary additional duty orders to Lima Batter, 3d Battalion. 10th Marines and deployed to Ramadi, Iraq from August 2005 to March 2006. Upon return from deployment, Sergeant Major Sandlin returned to the Headquarters Battalion, 2nd Marine Division. In October 2006 he was assigned to II Marine Expeditionary Force and deployed to Fallujah, Iraq from January 2007 to January 2008, he was meritoriously promoted to Sergeant in November 2007.

In June of 2008, Sergeant Major Sandlin reported to Combat Instructor School at the School of Infantry East. Upon graduation he was assigned to Golf Company, Marine Combat Training Battalion to serve as a Marine Corps Combat Instructor. In January 2010 he was meritorious promoted to Staff Sergeant. In August of 2010 Sergeant Major Sandlin was transferred to Advanced Infantry Training Battalion to work as a Martial Arts Instructor Trainer at the School of Infantry East Satellite Martial Arts Instructor Course.

Upon completion of his tour in March 2012, Sergeant Major Sandlin received orders to Marine Aircraft Group-36 Okinawa, Japan. While serving as the Chemical Biological Radiological and Nuclear Chief (CBRN), and Anti- terrorism Force Protection Chief he participated in exercise Balikatan and Phiblex. In March 2013, Sergeant Major Sandlin executed orders to Marine Special Operations Support Group. Marine Special Operations Command where he served as the CBRN Chief and Training Chief until March 2015. In March 2015, Sergeant Major Sandlin received orders to the Staff Non Commissioned Officer Academy, Camp Lejeune, North Carolina where he has served as a faculty Advisor at the Sergeants, Career, Advanced Courses, and served as the Staff Non Commissioned Officer in Charge of the Career School until June 2018.

In June 208, Sergeant Major Sandlin received orders to 5th Marine Regiment to serve as the CBRN Chief. First Sergeant Sandlin served as the CBRN chief until selected to first sergeant. Sergeant Major Sandlin was frocked to First Sergeant in January 2019, and executed orders to 3d Battalion 5th Marines to assume duties as Company First Sergeant for Lima Company. In May 2019 to November 2019, Sergeant Major Sand in deployed in support of the 11th Marine Expeditionary Unit Western Pacific Deployment 19-2. In January 2020, Sergeant Major Sandlin assumed the billet of Company First Sergeant for Weapons Company. In February 2020 to May 2020, Sergeant Major Sandlin deployed to the border in support of Special Purpose Marine Air Ground Task Force Southwest Border Mission. February 2021, Sergeant Major Sandlin assumed duties as the Company First Sergeant for Headquarters and Service Company. In May 2021 to November 2021, Sergeant Major Sandlin deployed in support of the 31st Marine Expeditionary Unit 21-2. In January 2022, Sergeant Major Sandlin executed orders to Marine Wing Support Squadron 373 where he served as the Airfield Operations Company First Sergeant until August 2023.

Sergeant Major Sandlin is currently assigned as the Command Senior Enlisted Leader, for Marine Aerial Refueler.

Sergeant Major Sandlin has earned a Bachelor of Science Degree with a major in Management of Human Resources from Bellevue University. His personal awards include the Meritorious Service Medal. Navy and Marine Corps Commendation Medal with gold star in lieu of third award, Navy and Marine Corps Achievement Medal gold star in lieu of second award and Military Outstanding Volunteer Service Medal.