What did the declassified documents reveal?

This is CIA Inspector General Report on Operation Mongoose, released on December 16, 2020, through The Black Vault. The document is a reconstruction of Agency involvement in plans to assassinate Fidel Castro, an imperfect history due to the extreme sensitivity of the operations being discussed or attempted. The report was released in response to a Freedom of Information Act request from John Greenewald, Jr. on May 5, 2016, with the reference number F-2016-01502. The CIA conducted a search of their system of previously released databases and located the enclosed document, consisting of 143 pages. Declassified and Approved for Release by the Central Intelligence Agency, the report states that it has been reconstructed from available sources, including a 1977 Inspector General's report. The original report was created in 1967 and was returned to the CIA's Inspector General's office on May 22, 1967, with instructions to destroy all copies and other derived materials. The report notes that the text of the original report has been read only by a few individuals, including Richard Helms, Director of Central Intelligence, and S. Earle, Inspector General. All typographical or drafts and other text were done by the authors. The report was filed with the CIA's Security Office, used as a source material, and was declassified on May 23, 1977. The report discusses early planning on the assassination of Fidel Castro, involving lethal chemicals and cars. It also mentions possible ways to poison Castro, including using pills. The sequence of events is described, including the use of pills and the involvement of various individuals, including Varo, Roselli, and O'Connell. The report states that Roselli associated with O'Connell, and that Varo was not involved in the operation. It also mentions that the pills were tested on pigs, and that Roselli reported that the pills were a cure for a three-celled cancer. The report notes that Varo planned to send three pills to Cuba, and that Roselli came to Washington to meet with Barvey's associates. The report was truncated for this narration, but the full source is available through The Black Vault. This is what the public record looks like at its most ordinary. The CIA Inspector General Report on Operation Mongoose is available at storyflo.com and at https://documents.theblackvault.com/documents/cia/CIA-IG-AssassinationPlotFidelCastro.pdf.

Why was this case declassified?

This material entered the public record through the U.S. declassification and Freedom of Information Act (FOIA) process.

Case · DAILY-045

CIA Inspector General Report on Operation Mongoose

JUL 5 · 2026Narrated by daily-declassified-cia-inspector-general-report-on-operation-mongoose3 minLast updated July 5, 2026

The short version

This is CIA Inspector General Report on Operation Mongoose, released on December 16, 2020, through The Black Vault. The document is a reconstruction of Agency involvement in plans to assassinate Fidel Castro, an imperfect history due to the extreme sensitivity of the operations being discussed or attempted.

Date: JUL 5 · 2026
Release: Declassified · U.S. public record (FOIA)

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What was CIA Inspector General Report on Operation Mongoose about?: This is CIA Inspector General Report on Operation Mongoose, released on December 16, 2020, through The Black Vault. The document is a reconstruction of Agency involvement in plans to assassinate Fidel Castro, an imperfect history due to the extreme sensitivity of the operations being discussed or attempted.
Why was this case declassified?: This material entered the public record through the U.S. declassification and Freedom of Information Act (FOIA) process. Storyflo narrates it directly from the public release.

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