Did the Cubans assassinate Kennedy?

The Telegraph reports:

The Cuban secret service was behind the assassination of President John F Kennedy, according to evidence presented in a new television documentary.

Rendezvous with Death, to be shown on German television on Friday, offers the most convincing evidence that Fidel Castro's regime was behind the most talked-about murder of the 20th century.

A former agent of the Cuban secret service G2 talks for the first time about how Lee Harvey Oswald, the assassin, was, he claims, pointed out to the Cubans by the KGB.

Was Lee Harvey Oswald that good of a shooter?