Dean retired from the U.S. Army as a Command Sergeant Major after a 28-year career. He has appeared on radio programs, TV documentaries and at conferences discussing the subject of UFOs and a government cover up of alien visitations to Earth. Dean claimed to have viewed a classified government document called "The Assessment" that allegedly discussed threats posed by alien activity on Earth, and concluded that no such threats existed. Dean said he considers himself a professional UFO researcher and had "cosmic top secret" clearance while in the military. In 1992 while employed as emergency services coordinator for Pima County, Arizona, Dean sued his employer for discrimination, saying he was treated unfairly because of his belief in UFOs, and because of his age, reportedly settling for $100,000.