a lone assassin. As opposed to several assassins.
Lee Harvey Oswald killed JFK alone and that there was no conspiracy.
If by chance you mean the Warren Commission, they concluded that JFK was killed by Lee Oswald, and that while other people may have been involved, they were unknown.
Most researchers say that the Warren Commission was not correct in this finding. Aside from a few Warren Commission proponents, researchers tend to agree with the witnesses and ballistics evidence that suggests that there were multiple shooters involved in the assassination. This belief was supported by the House Select Committee on Assassinations, which concluded with near certainty that there was a second shooter.
Warren Commission
JFK was killed by the lone gunman Lee Harvey Oswald without help or conspirators.
The Warren Commission Report claimed Lee Harvey Oswald shot and killed Dallas Police Officer J. D. Tippit.
President John F. Kennedy was assassinated in Dallas, Texas on November 22, 1963 at aged 46. Lee Harvey Oswald was arrested for the crime. Oswald was murder two days later by Jack Ruby. Various groups believed that Kennedy was the victim of a conspiracy. However, the FBI and the Warren Commission officially concluded that Oswald was the lone assassin.
President Gerald Ford (1974 to 1976) served on the 1964 Warren Commission to investigate the 1963 murder of President John F. Kennedy, (and Officer JD Tippet) by Lee Harvey Oswald, after Oswald was killed by Jack Ruby. The conclusion of the Warren Commission was that Oswald murdered both Kennedy and Tippet and he acted alone. Ruby acted alone when he killed Oswald.
President John F. Kennedy was assassinated in Dallas, Texas on November 22, 1963 at aged 46. Lee Harvey Oswald was arrested for the crime. Oswald was murder two days later by Jack Ruby. Various groups believed that Kennedy was the victim of a conspiracy. However, the FBI and the Warren Commission officially concluded that Oswald was the lone assassin.
President John F. Kennedy was assassinated in Dallas, Texas on November 22, 1963 at aged 46. Lee Harvey Oswald was arrested for the crime. Oswald was murder two days later by Jack Ruby. Various groups believed that Kennedy was the victim of a conspiracy. However, the FBI and the Warren Commission officially concluded that Oswald was the lone assassin.
President John F. Kennedy was assassinated in Dallas, Texas on November 22, 1963 at aged 46. Lee Harvey Oswald was arrested for the crime. Oswald was murder two days later by Jack Ruby. Various groups believed that Kennedy was the victim of a conspiracy. However, the FBI and the Warren Commission officially concluded that Oswald was the lone assassin.
There hasn't been a recent breakthrough in the investigation of the John F. Kennedy assassination. The official version of events is that Kennedy was killed by Lee Harvey Oswald acting alone, which was concluded by the Warren Commission in 1964. While there have been theories and speculation over the years, no concrete evidence has emerged to change the official narrative.