Get answers to some of the most frequently asked questions about President John F. Kennedy's assassination, investigation and the aftermath. 

Assassination:

Q: Why was Kennedy in Texas?
A: Kennedy went to Dallas to address the Dallas Citizens Council's annual meeting at the Dallas Trade Mart. His undelivered speech was on the subject of national security.

Q: How severely wounded was Texas governor John Connally?
A: Governor Connally suffered a shattered rib; splintered bones in his wrist and forearm; and bullet puncture wounds to his back, lung, chest and thigh.

Q: Why did First Lady Jacqueline Kennedy climb onto the back of the car after the shooting?
A: Jacqueline Kennedy climbed on the back of the car to retrieve fragments from the president's head, though she had no memory of it afterward.

Q: Was Kennedy killed instantly?
A: The first physician to see the president at Parkland Memorial Hospital, within minutes of his arrival at 12:43 p.m., reported hearing a heartbeat, but finding no pulse or blood pressure.

Q: What was the official cause of Kennedy's death?
A: Dr. George Gregory Burkley signed Kennedy's death certificate, which listed "Gunshot wound, skull" as the cause of death.

Q: When was the president declared dead?
A: Kennedy was declared dead at 1 p.m., 17 minutes after he arrived at the hospital.

Q: Where was Vice President Lyndon Johnson at the time of the shooting?
A: The Vice President was in the motorcade, two cars behind Kennedy's.

Q: How many shots were fired?
A: The Warren Commission determined that three shots were fired during the assassination.

Q: How far is the hospital from the site of the shooting?
A: Parkland Memorial Hospital is about four miles from Dealey Plaza.

Investigation:

Q: Who led the initial investigation?
The Dallas Police and the FBI conducted the initial investigation in the 24 hours after the assassination.

Q: Was Abraham Zapruder the only person to film the assassination?
A: At least two people in addition to Abraham Zapruder filmed the last bullet hitting President Kennedy: Orville Nix and Mary Muchmore.

Q: When was the Warren Commission established?
A: President Johnson established the Warren Commission on November 29, 1963 -- a week after the assassination.

Q: When did the Warren Commission issue a report?
A: The Warren Commission presented its report on September 24, 1964.

Q: How long was the Warren Commission Report?
A: The Warren Commission Report was 888 pages long; the commission's published hearings ran to 26 volumes.

Q: According to the Warren Commission, who killed Kennedy?
A: The Warren Commission determined that Lee Harvey Oswald -- acting alone -- shot President Kennedy and Governor Connally.

Q: Were there other official investigations into the Kennedy assassination?
A: In the 1970s, two other groups in Washington, D.C. investigated Kennedy's assassination: the President's Commission on CIA Activities Within the United States and the House Select Committee on Assassinations. A New Orleans district attorney, Jim Garrison, led his own controversial investigation in 1967.

Q: According to the House Select Committee on Assassinations, who killed Kennedy?
A: The House Select Committee on Assassinations reported that Kennedy "was probably assassinated as a result of a conspiracy. The committee was unable to identify the other gunmen or the extent of the conspiracy."

Q: According to the President's Commission on CIA Activities Within the United States, who killed Kennedy?
A: The President's Commission on CIA Activities Within the United States determined that "the findings of the Warren Commission regarding a lone assassin were correct."

Q: Jim Garrison used Sodium Pentathol when interviewing witness Perry Russo. What does it do?
A: Sodium Pentathol is a depressant drug that some believe to act as a "truth serum." It is often used in general anesthesia.

Aftermath:

Q: Where was Lee Harvey Oswald when he was shot?
A: Lee Harvey Oswald was at Dallas police headquarters, in the process of a transfer to the Dallas County Jail, when local businessman Jack Ruby shot him.

Q: Where was President Kennedy buried?
A: President Kennedy was laid to rest at Virginia's Arlington National Cemetery on Monday, November 25, 1963, a national day of mourning.

Q: What happened to Jacqueline Kennedy after her husband's assassination?
A: In 1968, Jacqueline Kennedy married Greek tycoon Aristotle Onassis. After his death in 1975, she worked as a book editor in New York. She died in 1994 from cancer.

Q: What happened to Jack Ruby after his arrest?
A: Jack Ruby was convicted of Oswald's murder in 1964, The Texas Supreme Court overturned the conviction after Ruby's lawyers successfully argued that he could not receive a fair trial in Dallas due to the huge publicity surrounding the case. On January 3, 1967, while awaiting a second trial, Ruby died from cancer-related complications.

Q: What happened to Lee Harvey Oswald's Russian-born wife, Marina?
A: Marina Oswald remarried in 1965, and remained in Texas. Her two daughters with Oswald, June (born in 1962) and Rachel (born in 1963), took the surname of their stepfather.

Q: In the days after Kennedy's death, how many people believed there was a conspiracy behind the assassination?
A: A November 1963 Gallup poll found that 52 percent of people polled believed there was a conspiracy behind the assassination of President Kennedy.

Q: How many people today believe there was a conspiracy behind the assassination?
A: Today 70 percent of Americans believe there was a conspiracy behind the assassination of President Kennedy.