Short answers, pulled from the story.
Lee Harvey Oswald, a former U.S. Marine who had defected to the Soviet Union and later returned to the United States, was charged with the assassination of President Kennedy on the 22nd of November 1963. The Warren Commission concluded that Oswald acted alone. Oswald was shot and killed two days later by Dallas nightclub owner Jack Ruby before he could stand trial.
Kennedy was assassinated in Dealey Plaza in Dallas, Texas, while riding in a presidential motorcade on Elm Street. The shots were fired from the sixth floor of the Texas School Book Depository building, which overlooked the motorcade route.
The Warren Commission concluded in its 888-page report, presented on the 24th of September 1964, that Lee Harvey Oswald acted alone in killing Kennedy and wounding Governor Connally, and that Jack Ruby acted alone in killing Oswald. The commission found no evidence of a conspiracy involving either man.
The single-bullet theory holds that one bullet caused all the non-fatal wounds to both President Kennedy and Governor Connally. According to the Warren Commission, the bullet entered Kennedy's upper back, exited his throat, then struck Connally's back, destroyed part of his fifth rib, punctured his lung, shattered his right wrist, and lodged in his left thigh. Conspiracy theorists dubbed it the "magic bullet theory."
The Zapruder film is twenty-six seconds of silent 8 mm footage recorded by Dallas tailor Abraham Zapruder from the pergola wall about sixty-five feet from the motorcade route. Frame 313 captures the moment of the fatal head shot. In 1999, an arbitration panel valued the complete film at $16 million, awarding Zapruder's heirs $615,384 per second of footage.
The House Select Committee on Assassinations concluded in its 1979 report that Kennedy was likely assassinated as a result of a conspiracy and that there was a high probability two gunmen fired at the president. However, the committee's chief evidence was acoustic analysis of a police Dictabelt recording, which the U.S. Justice Department subsequently found did not support the conclusion of a second gunman.