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.