In his introduction to Destiny Betrayed: JFK, Cuba and the Garrison Case by James DiEugenio, Zachary Sklar noted that "Although we still do not know the full extent of the disinformation campaign against Garrison, some evidence of it surfaced in a CIA memo dated April 1, 1967, and released in 1977 under the Freedom of Information Act."
The CIA's April 1, 1967 memo, entitled "Countering Criticism of the Warren Report," was apparently sent to "Chiefs, Certain Stations and Bases," and it included the following recommendations:
"Conspiracy theories have frequently thrown suspicion on our organization, for example by falsely alleging that Lee Harvey Oswald worked for us...
"...We do not recommend that discussion of the assassination question be initiated where it is not already taking place. Where discussion is active, however, addressees are requested:
"a. To discuss the publicity problem with liaison and friendly elite contacts (especially politicians and editors)...Urge them to use their influence...
"b. To employ propaganda assets...Book reviews and feature articles are particularly appropriate for the purpose..."