Snepp, in his capacity as a CIA analyst, was on hand for the Fall of Saigon and was one of the last Americans to leave the US Embassy, Saigon before the city fell to the North Vietnamese on April 30, 1975. Snepp was evacuated with other American personnel in Operation Frequent Wind. He wrote a memoir of the event, Decent Interval, in 1977, at great risk to his career. The book excoriates the tardy, improvised nature of the evacuation and laments the many Vietnamese nationals working for the Americans that were left behind.

The CIA attempted to stop Snepp from publishing his book. He accused the CIA of ruining his career and violating his First Amendment rights. The CIA, in return, claimed Snepp had violated his employment agreement by speaking out. He enlisted the help of the American Civil Liberties Union in his defense. In the end, the CIA won a court verdict against Snepp and attached the royalties from Decent Interval. He wrote a second book, Irreparable Harm, about his court battle with the CIA.

During the late 1980s, he taught a Journalism and the Law course at California State University, Long Beach.

He currently works as a producer for KNBC-TV in Los Angeles. In 2006 he won a Peabody Award for his KNBC investigative story "Burning Questions".

He was a technical consultant for the comedy film Spies Like Us.[1]