The group of Cubans carried out a range of anti-Castro actions, killing people and destroying property in Cuba and in USA. One commentator wrote that the group ranked "among the most violent and most notorious of the Cuban-exile groups devoted to overthrowing Fidel Castro’s regime in Havana." Another that "Alpha-66’s terrorist actions could fill a book, and various volumes at that."
"Five armed members of the group were captured in Cuba in December 1968, but U.S. authorities made no effort to punish Alpha 66 for violating neutrality laws. Two years later in September 1970, Cuban authorities announced the capture of nine more Alpha 66 commandos on the island.
The group was linked to a spate of bombings and assassinations in Miami during the 1970s, directed at Pro-Castro speakers. No Alpha 66 member was convicted of these crimes.
Similar actions in Cuba continued through the 1990s — including three drive-by shootings at the same Havana hotel between March 1994 and May 1995 — while the FBI professed inability to find the men responsible."
In 1976 Antonio Veciana told the House Select Committee on Assassinations that he obtained operational guidance from a CIA agent known as 'Maurice Bishop'. He said that the group was actively supported by the CIA from 1960 to 1973.