The motorcade then left the airport and proceeded along the parade route. Just prior to the shooting the Presidential car turned left at the intersection and started down an incline toward an underpass followed by 679X. After a very short distance I heard a loud report which sounded like a firecracker. It appeared to come from the right and rear and seemed to me to be at ground level. I stood up and looked to my right and rear in an attempt to identify it. Nothing caught my attention except people shouting and cheering. A disturbance in 679X caused me to look forward toward the President's car. Perhaps 2 or 3 seconds elapsed from the time I looked to the rear and then looked at the President. He was slumped forward and to his left, and was straightening up to an almost erect sitting position as I turned and looked. At the moment he was almost sitting erect I heard two reports which I thought were shots and that appeared to me completely different in sound than the first report and were in such rapid succession that there seemed to be practically no time element between them. It looked to me as if the President was struck in the right upper rear of his head. The first shot of the second two seemed as if it missed because the hair on the right side of his head flew forward and there didn't seem to be any impact against his head. The last shot seemed to hit his head and cause a noise at the point of impact which made him fall forward and to his left again. Possibly four or five seconds elapsed from the time of the first report and the last.

At the end of the last report I reached to the bottom of the car and picked up the AR 15 rifle, cocked and loaded it, and turned to the rear. At this point the cars were passing under the over-pass and as a result we had left the scene of the shooting. I kept the AR 15 rifle ready as we proceeded at a high rate of speed to the hospital.

Agent Clint Hill was riding across the rear and the top of 100X in a horizontal position. He looked into the rear of 100X and turned toward 679X and shook his head several times. I received the impression that the President at the least was very seriously injured. A few moments later shift leader Emory Roberts turned to the rest of us in the car and said words to the effect that when we arrive at the hospital some of us would have to give additional protection to the Vice President and take him to a place of safety. He assigned two of the agents in the car to this duty. I was told to have the AR 15 ready for use if needed.

When we arrived at the hospital the President and Governor Connally were taken inside and about the same time the Vice President had arrived. I requested him to come into the hospital to a place of safety and he was surrounded by his detail and the other assigned agents, and myself and led into the hospital. When he entered I returned the gun to 679X as ordered by Agent Roberts.

At the corner of Houston and Elm Streets I verified with Chief Curry that we were about five minutes from the Trade Mart and gave this signal over my portable White House Communications radio. We were just approaching a railroad overpass and I checked to see if a police officer was in position there and that no one was directly over our path. I noticed a police officer but also noticed a few persons on the bridge and made motions to have these persons removed from over our path. As the lead car was passing under this bridge I heard the first loud, sharp report and in more rapid succession two more sounds like gunfire. I could see persons to the left of the motorcade vehicles running away. I noticed Agent Hickey standing up in the follow-up car with the automatic weapon and first thought he had fired at someone. Both the President's car and our lead car rapidly accelerated almost simultaneously. I heard a report over the two-way radio that we should proceed to the nearest hospital. I noticed Agent Hill hanging on to the rear of the President's vehicle. A motorcycle escort officer pulled alongside our lead car and said the President had been shot. Chief Curry gave a signal over his radio for police to converge on the area of the incident. I requested Chief Curry to have the hospital contacted that we were on the way. Our lead car assisted the motorcycles in escorting the President's vehicle to Parkland Hospital.

Special Agent Ready, on the right front running board of the Presidential follow-up car, heard noises that sounded like firecrackers and ran toward the President's limousine. But he was immediately called back by Special Agent Emory K. Roberts, in charge of the follow-up car, who did not believe that he could reach the President's car at the speed it was then traveling. Special Agent George W. Hickey, Jr., in the rear seat of the Presidential follow-up car, picked up and cocked an automatic rifle as he heard the last shot. At this point the cars were speeding through the underpass and had; left the scene of the shooting, but Hickey kept the automatic weapon ready as the car raced to the hospital. Most of the other Secret Service agents in the motorcade had drawn their sidearms.

This time, one of those theories will be played out in federal court in Baltimore, where a former U.S. Secret Service agent assigned to protect John F. Kennedy on the day of his death nearly 33 years ago is suing for libel.

A little-known book called Mortal Error: The Shot That Killed JFK claims the agent slipped and accidentally pulled the trigger of his high-powered AR-15 rifle, striking Kennedy in the head Nov. 22, 1963.

It's a theory - first advanced by a ballistics expert from Towson - that just won't go away.

"We're trying to stop this now while Hickey's still alive," said Mark S. Zaid, an attorney for former agent George W. Hickey, 73. "He doesn't want his grandchildren growing up and hearing other children say, "Hey, your grandfather killed the president of the United States."

Hickey is seeking untold damages from St. Martin's Press in New York. He also wants an apology, preferably printed on full-page ads in The New York Times, The Washington Post and The Baltimore Sun, his lawyer said.

It's not likely Hickey will see an apology anytime soon.

"The case is utterly without merit," said David N. Kaye, chief attorney for St. Martin's.

Hickey's suit, filed last week in U.S. District Court in Baltimore, says "Mortal Error" is simply false, and other Kennedy assassination experts agree. Published in 1992, the 350-page book recounts the day of the assassination and focuses on the actions of Hickey.

Written by Missouri-based journalist Bonar Menninger, the book claims that when Hickey heard the first volley in Dallas' Dealey Plaza that day, he pulled out an AR-15 assault-type rifle while standing in a trailing Cadillac outfitted for the Secret Service.

The first shot by Lee Harvey Oswald (according to Mortal Error) hit the pavement. The second -- the so-called "magic bullet" -- struck Kennedy in the neck. At that point, Hickey lost his balance in the Cadillac, "Mortal Error" claims, and he accidentally pulled the trigger, hitting the president in the head.

The lawsuit - which does not name Menninger as a defendant - says Mortal Error is "replete with false and misleading defamatory statements and innuendos.'' The suit says the book libels Hickey by accusing him of a crime - negligent homicide for shooting Kennedy - and by claiming that the agent has participated in a deliberate coverup for three decades.

The lawsuit quotes numerous passages from the book, calling them libelous and saying they were published with "reckless disregard" of the truth.

"So Hickey reaches down and grabs the AR-15 off the floor, flips off the safety and stands up on the seat, preparing to return fire," one passage reads. "But his footing is precarious. The follow-up car hits the brakes or speeds up. Hickey begins to swing the gun around to draw a bead on Oswald, but he loses his balance. He begins to fall. And the barrel happens to be pointing toward Kennedy's head. And the gun happens to go off."

Hickey, who lives in Abingdon, declined through his lawyer to discuss the case. Menninger did not return a call to his home in Kansas City, Mo. But Howard Donahue, the ballistics expert responsible for the theory, said Wednesday that he still stands by it.

Many conspiracy theorists unhappy with the official account of the assassination of John F. Kennedy have pointed to evidence they believe shows that the president was shot twice, from different directions.

Now a new documentary has come up with a new twist on the conspiracy theory, claiming that a Secret Service agent was the man who fired that shot... by accident.

JFK: The Smoking Gun claims that George Hickey, a Secret Service man riding in the car behind Kennedy, accidentally fired his weapon on November 22, 1963.

It alleges that a cover-up was then carried out to save the blushes of the agency whose main role is to protect serving and former U.S. leaders - leaving the many loose ends that have long raised suspicions.

It is said that as much as 75 per cent of the American public do not believe the official account of the Kennedy assassination.

The new documentary is based on the work of Colin McLaren, a veteran Australian police detective who has undertaken a four-year investigation into the killing.

His theories are based on the work of Howard Donahue, who spent two decades probing the assassination and whose work was presented in the book Mortal Error: The Shot That Killed JFK, by Bonar Menninger.