Warren Commission

The President's Commission on the Assassination of President Kennedy, known unofficially as the Warren Commission, was established by President Lyndon B. Johnson on November 29, 1963. Its purpose was to the assassination of United States President John F. Kennedy that had taken place on November 22, 1963. 
Commission report.
The Commission took its unofficial name—the Warren Commission—from its chairman, Chief Justice Earl Warren. According to published Transcripts of Johnson's presidential telephone conversations, some major officials did not want to form this commission. Also that several commission members took part only reluctantly. One of their chief reservations was that a commission would create more controversy and people's fears would be proved valid.
The 88th U.S. Congressional session passed Senate joint resolution 137 authorizing the Presidential appointed Commission to report on the assassination of President John F. Kennedy.
Its 889-page final report was presented to President Johnson on September 24, 1964. It was made public three days later. It concluded that President Kennedy was assassinated by Lee Harvey Oswald. They also stated that Oswald acted entirely alone. The commission said that Jack Ruby also acted alone when he killed Oswald two days later. The Commission's findings have proven controversial. They have been both challenged and supported by later studies.