“JUL 21, 1960: CIA headquarters sends a cable to Havana regarding an upcoming meeting between a Cuban volunteer agent and Raul Castro. The cable states that ‘Possible removal top three leaders is receiving serious consideration at HQS,’ enquiring whether the Cuban agent is sufficiently motivated to risk arranging an accident for Raul Castro, and offering $10,000 after successful completion. After the agent agrees to carry out the task, the CIA cancels the assignment.”
“The Bay of Pigs Invasion/Playa Giron: A Chronology of Events,” The National Security Archive, NSArchive2.gwu.edu