Late in his life, former president Lyndon B. Johnson told a reporter that he didn't believe the Warren Commission's finding that Lee Harvey Oswald acted alone in killing President John F. Kennedy. Johnson thought Cuban president Fidel Castro was behind it. After all, Johnson said, Kennedy was running "a damned Murder, Inc., in the Caribbean," giving Castro reason to retaliate.

Murder, Inc., tells the story of the CIA's assassination operations under Kennedy up to his own assassination and beyond. James H. Johnston was a lawyer for the Senate Intelligence Committee in 1975, which investigated and first reported on the Castro assassination plots and their relation to Kennedy's murder. Johnston examines how the CIA steered the Warren Commission and later investigations away from connecting its own assassination operations to Kennedy's murder. He also looks at the effect this strategy had on the Warren Commission's conclusions that assassin Lee Harvey Oswald acted alone and that there was no foreign conspiracy.

Sourced from in-depth research into the "secret files" declassified by the JFK Records Act and now stored in the National Archives and Records Administration, Murder, Inc. is the first book to narrate in detail the CIA's plots against Castro and to delve into the question of why retaliation by Castro against Kennedy was not investigated.