After his death, New Orleans district attorney Jim Garrison alleged that he had been involved in the assassination of John F. Kennedy.

[8] In December 1955, Banister publicly revealed 91 members of the police who were involved in graft, after a list was found at the home of an illegal lottery operator.

[9] In March 1957, NOPD Superintendent Provosty Dayries suspended Banister after witnesses reported he had drawn his revolver while threatening a bartender at the Old Absinthe House on Bourbon Street in the French Quarter.

[12] Later in March, Banister appeared before the state's Joint Legislative Segregation Committee where he told investigators that he had "documentary proof of clear and specific communist directions to promote friction between the races".

[16] Around the corner but located in the same building, with a different entrance, was the address 544 Camp Street, which would later be found stamped on Fair Play for Cuba Committee leaflets distributed by Lee Harvey Oswald, the assassin of President John F.

[17] The Newman Building housed militant anti-Castro groups, including the Cuban Revolutionary Council (October 1961 to February 1962), as well as Sergio Arcacha Smith's Crusade to Free Cuba Committee.

"[8] The New Orleans States-Item newspaper reported an allegation that Banister served as a munitions supplier for the 1961 Bay of Pigs Invasion and continued to deal weapons from his office until 1963.

In 1963, Banister and anti-Castro activist David Ferrie began working for a lawyer named G. Wray Gill and his client, New Orleans Mafia boss Carlos Marcello.

[21][8] On the afternoon of November 22, 1963, the day that President John F. Kennedy was assassinated, Banister and one of his investigators, Jack Martin, were drinking together at the Katzenjammer Bar, located next door to 544 Camp Street in New Orleans.

When questioned about the incident in December 1977 by investigators for the United States House Select Committee on Assassinations (HSCA), Martin said that in the heat of the argument just prior to the pistol-whipping he had said to Banister: "What are you going to do — kill me like you all did Kennedy?

Martin claimed that Banister, Ferrie and a group of anti-Castro Cuban exiles were involved in operations against Castro's Cuba that included gun running and burglarized armories.

[28] As Garrison continued his investigation, he became convinced that a group of right-wing activists, including Banister, Ferrie and Clay Shaw, were involved in a conspiracy with elements of the Central Intelligence Agency (CIA) to kill Kennedy.

Garrison would later claim that the motive for the assassination was anger over Kennedy's attempts to obtain a peace settlement in both Cuba and Vietnam.

In American Tabloid, Banister organizes John Kennedy's assassination, which is based on Ward Littell's original plan.