JFK files: The key points about the 1963 assassination
Thousands of previously classified documents relating to the assassination of President John F Kennedy in 1963 have been released by the US government.
As people examine all 2,800 files, here are the most interesting points so far. NB many files contain unverified raw intelligence.
FBI concerned about conspiracy theories
In a memo written the day Oswald was killed, FBI director J Edgar Hoover expressed concern about the spread of conspiracy theories.
"The thing I am concerned about is having something issued so that we can convince the public that Oswald is the real assassin," he said.
Oswald spoke to a KGB officer
A memo from the CIA, based on an intercepted phone call, suggests Oswald spoke with a KGB officer at the Russian embassy in Mexico City.
It says that on 28 September 1963 he spoke with Valeriy Vladimirovich Kostikov, an "identified KGB officer" who worked for a department "responsible for sabotage and assassination".
Oswald later called the embassy and, in "broken Russian", asked if there was "anything new concerning the telegram to Washington".
FBI warned police to protect the killer
Lee Harvey Oswald, who shot and killed President Kennedy, was quickly arrested and charged. But two days later Oswald was shot dead in the basement of the Dallas police department by Jack Ruby, a local nightclub owner.
But could more have been done to protect him?
One memo reveals the FBI had warned Dallas police of a death threat made against Oswald.
FBI director J Edgar Hoover said: "We at once notified the chief of police and he assured us Oswald would be given sufficient protection. However, this was not done."
Kennedy's death worried the USSR
The idea of a leaderless United States did not appeal to some Soviet officials.
They "were fearful that without leadership, some irresponsible general in the United States might launch a missile at the Soviet Union", according to one memo.
It also says the Soviets were "convinced the assassination was not the deed of one man" but rather a "carefully planned campaign in which several people played a part".
Private detectives tried to spy on Kennedy
An FBI memo from before Kennedy was elected president describes attempts by a private detective to spy on the then senator.
It says a "high priced Hollywood call girl" told FBI agents that private detective Fred Otash had contacted her to ask about Senator Kennedy's involvement in "sex parties".
The private detective also suggested equipping the woman with "a recording device" to take down any "indiscreet statements" from Senator Kennedy.
She refused, and said she was unaware of any "indiscretions".
British paper received an anonymous call
One memo describes how a British local newspaper, the Cambridge News, received an anonymous call about "some big news" in the US, just 25 minutes before the assassination.
"The caller said only that the Cambridge News reporter should call the American embassy in London for some big news and then hung up", it says.
A copy of the memo was released by the National Archives in the US in July, but had gone unreported.
Was a US president in the Ku Klux Klan?
An FBI report alleges that President Lyndon B Johnson, who took office after President Kennedy was killed, may have been a member of the KKK.
An informant said the white supremacist group had "documented proof that President Johnson was formerly a member of the Klan in Texas during the early days of his political career".
However, no proof was provided.
Fond memories of Lee Harvey Oswald