Sam Papich was born in 1914. He joined the Federal Bureau of Investigation in 1941 and during the Second World War he did undercover work in South America.

In 1961 he was investigating Sam Giancana. Papich was approached by CIA agents who were working with Giancana in the plot to assassinate Fidel Castro. He told J. Edgar Hoover about what the CIA/Mafia plot. Papich was assigned the task of spying on the operation to kill Castro. Later he became the FBI's liaison officer with various divisions within the Central Intelligence Agency.

In 1963 Papich was involved in the investigation of the assassination of John F. Kennedy. His main responsibility was coordinating CIA information for FBI agents investigating Lee Harvey Oswald. Papich told a journalist that he had serious doubts about the reliability of the Warren Report. He found it difficult to believe that Oswald was the lone gunman: “This would have been very fancy shooting even for the best marksmen in the FBI. But everything we had on Oswald indicated that he was a crappy shot.”

The same journalist later claimed that The Man Who Knew Too Much by Dick Russell contained some very important information that had been missed: "Several times he stopped the interview and referred me to that book. It was very strange, as if he was trying to tell me something. I’m not sure what, but he just kept saying it was an interesting account of events. Knowing Sam as I came to, I have been left with the impression that he regarded certain threads in that book has worthy of further exploration, but thought that journalists had not picked up on those threads."

Papich retired from the FBI in 1970. Later he served on the President's Foreign Advisory Board and as a consultant to the Joint Chiefs of Staff in an assessment of Soviet intelligence deception. In 1973 Papich became director of the Organized Crime Prevention Council.

Sam Papich died in Albuquerque on 22nd December, 2004.