Lock is a 1982 graduate and former Assistant Professor of the U.S. Military Academy at West Point. He enlisted in the Army in 1974 and served as a Non-Commissioned Officer until 1978 when he was commissioned. His military and advanced civil schooling education includes the Engineer Officer Basic Course, the Infantry Officer Advanced Course, the Combined Arms Services Staff School, the Command and General Staff College, and a master of science degree from Rensselaer Polytechnic Institute.