Clay Shaw was a businessman in New Orleans. He joined the U.S. Army and took part in the fighting in Europe. He served as an aide to General Charles Thrasher and by the time he retired in 1946 he had reached the rank of major general.

He played an important role in the restoration of historic New Orleans sites and in 1962 he established the city's International Trade Mart. He was a member of the World Trade Development Committee and a member of the board of directors of Permindex.

In 1961, Jim Garrison was elected as the city's district attorney. He developed a good reputation and in his first two years he never lost a case. Garrison took a keen interest in the case of Lee Harvey Oswald. After investigating the matter he became convinced that a group of right-wing activists, including Shaw, Guy Bannister, David Ferrie and Carlos Bringuier were involved in a conspiracy with the Central Intelligence Agency (CIA) to kill John F. Kennedy. Garrison claimed this was in retaliation for his attempts to obtain a peace settlement in both Cuba and Vietnam.

Two of those being investigated died: Guy Bannister (June, 1964) and David Ferrie (February, 1967), but in March, 1967, Shaw was charged with conspiring to assassinate Kennedy, with the help of Oswald, Ferrie, and others. At the trial in February, 1969, Perry Russo claimed that in September, 1963, he overheard Shaw and Ferrie discussing the proposed assassination of John F. Kennedy. It was suggested that the crime could be blamed on Fidel Castro.

Clay Shaw was also a homosexual in a time and a place that viewed homosexuality as abhorrent, immoral, and criminal. In that society, gay people, particularly prominent citizens like Clay Shaw, were compelled to remain closeted and were extremely vulnerable.

On March 1, 1967, Jim Garrison arrested Clay Shaw and charged him with conspiring to assassinate President Kennedy. Garrison knew Shaw was gay, but the general public did not, though soon Shaw's homosexuality was exposed. The discreetly gay Shaw was soon described as a sadist as well as a homosexual.

During Shaw's trial Russo's testimony was discredited by the revelation that he underwent hypnosis and had been administered sodium pentathol, or "truth serum," at the request of the prosecution. It claimed that Russo only came up with a link between Clay Shaw, David Ferrie and Lee Harvey Oswald after these treatments. The jury found Shaw not guilty of conspiring to assassinate John F. Kennedy.

In 1973 Jim Garrison lost the office to Harry Connick. After leaving his post as district attorney Garrison wrote a book about his investigations of the Kennedy assassination, On the Trail of the Assassins (1988).