Santos attended Jackson Middle School and Austin High School in Houston, Texas. Season 6, episode 22 has Santos introduced as a graduate of the United States Air Force Academy, implying a career in the Air Force, not the Marine Corps, or perhaps somehow serving first the Air Force and subsequently the Marines, but later episodes consistently refer to him attending the United States Naval Academy at Annapolis, graduating at the top of his class with a degree in engineering. At Annapolis, he played football until he injured his knee. Santos speaks three languages (English, Spanish and Portuguese). After graduating, he was commissioned as an officer in the Marines. Santos was a Naval Aviator, qualified on carrier-based F/A-18 Hornet fighter aircraft, and saw action during the first Persian Gulf War. Since leaving active duty in 1993, he has served in the Marine Reserves.