Major John “JD” D. Greer retired after 21 years in the United States Army and served in such units as the 5th Special Forces Group (Airborne), 160th Special Operations Aviation Regiment (Airborne) and Army Special Operations Command at Fort Bragg in North Carolina. He held many duty positions, including Special Operations Engineer Sergeant, Company Commander, Program Manager and Action Officer at the Pentagon for the Army Special Operations Commander as a result of 9/11.
In 2006, Major Greer was hit by a roadside bomb in Baghdad, Iraq, and the explosion amputated his right arm below the elbow. He also suffers from a traumatic brain injury (TBI) and post-traumatic stress disorder (PTSD). Major Greer has undergone multiple surgeries and periods of rehabilitation, and has participated with and served as a mentor for the Wounded Warrior Project and Soldiers Undertaking Disabled Scuba. He feels that assisting others has helped him significantly. He is currently training for future athletic events and is working on his first book, which is currently untitled.