President Kennedy was assassinated on November 22, 1963 in Dallas, Texas, during a motorcade through the city, en route to a luncheon at the Dallas Trade Mart.
The president and Mrs. Kennedy were riding in an open limousine containing three rows of seats.
The Kennedys were in the rear seat of the car, the governor of Texas, John Connally, and his wife, Nellie Connally, were in the middle row, Secret Service agent William Greer was driving and the president's bodyguard, Roy Kellerman, was also in the front row.

Hill was riding on the left front running board of the Secret Service car immediately behind the presidential limousine.
After the second shot, Hill began running to overtake the moving car in front of him, but the third shot had hit Kennedy in the head by the time that he arrived at the limousine.
He climbed from the rear bumper, crawling over the trunk to the back seat where the president and First Lady were located.
In the moments immediately after the fatal shots, Mrs. Kennedy climbed out of the back seat toward the trunk.
Hill pushed her back into the car and covered her and the fatally wounded president with his body.

Hill, along with Secret Service agents Kellerman, Greer, and Rufus Youngblood, provided testimony to the Warren Commission in Washington, D.C. on March 9, 1964.

Hill grabbed a small handrail on the left rear of the trunk, normally used by bodyguards to stabilize themselves while standing on small platforms on the rear bumper.
According to the Warren Commission's findings, there were no bodyguards stationed on the bumper that day because:
...the President had frequently stated that he did not want agents to ride on these steps during a motorcade except when necessary.
He had repeated this wish only a few days before, during his visit to Tampa, Florida.

The notion that the president's instructions in Tampa jeopardized his security in Dallas has since been denied by Hill and other agents.
Regardless of the Warren Commission's findings, photos taken of the motorcade along earlier segments of the route show Hill riding on the step at the back of the car.

As an alternative explanation, fellow agent Gerald Blaine cites the location of the shooting:
We were going into a freeway, and that's where you take the speeds up to 60 and 70 miles an hour.
So we would not have had any agents there anyway.

Hill grabbed the handrail less than two seconds after the fatal shot to the President.
The driver then accelerated, causing the car to slip away from Hill, who was in the midst of trying to leap onto it.
He succeeded in regaining his footing and jumped onto the back of the quickly accelerating vehicle.

As he got on, Mrs. Kennedy, apparently in shock, was crawling onto the flat rear trunk of the moving limousine.
Hill later told the Warren Commission that he thought Mrs. Kennedy was reaching for a piece of the president's skull that had been blown off.
He crawled to her and guided her back into her seat.
Once back in the car, Hill placed his body above the president and Mrs. Kennedy.
Meanwhile, in the folding jump seats directly in front of them, Mrs. Connally had pulled her wounded husband, Governor John Connally, to a prone position on her lap.

Agent Kellerman, in the front seat of the car, gave orders over the car's two-way radio to the lead vehicle in the procession "to the nearest hospital, quick!"
Hill was shouting as loudly as he could: "To the hospital, to the hospital!"
En route to the hospital, Hill flashed a "thumbs-down" signal and shook his head from side to side at the agents in the follow-up car, signaling the graveness of the president's condition.

The limousine then rapidly exited Dealey Plaza and sped to Parkland Memorial Hospital, only minutes away, followed by other vehicles in the motorcade.
Hill maintained his position shielding the couple with his body, and was looking down at the president.
He later testified:
The right rear portion of his head was missing.
It was lying in the rear seat of the car.
His brain was exposed.
There was blood and bits of brain all over the entire rear portion of
President Kennedy was assassinated on November 22, 1963 in Dallas, Texas, during a motorcade through the city, en route to a luncheon at the Dallas Trade Mart. The president and Mrs. Kennedy were riding in an open limousine containing three rows of seats. The Kennedys were in the rear seat of the car, the governor of Texas, John Connally, and his wife, Nellie Connally, were in the middle row, Secret Service agent William Greer was driving and the president's bodyguard, Roy Kellerman, was also in the front row.
Hill was riding on the left front running board of the Secret Service car immediately behind the presidential limousine. After the second shot, Hill began running to overtake the moving car in front of him, but the third shot had hit Kennedy in the head by the time that he arrived at the limousine. He climbed from the rear bumper, crawling over the trunk to the back seat where the president and First Lady were located. In the moments immediately after the fatal shots, Mrs. Kennedy climbed out of the back seat toward the trunk. Hill pushed her back into the car and covered her and the fatally wounded president with his body.
Hill, along with Secret Service agents Kellerman, Greer, and Rufus Youngblood, provided testimony to the Warren Commission in Washington, D.C. on March 9, 1964.
Hill grabbed a small handrail on the left rear of the trunk, normally used by bodyguards to stabilize themselves while standing on small platforms on the rear bumper. According to the Warren Commission's findings, there were no bodyguards stationed on the bumper that day because:
...the President had frequently stated that he did not want agents to ride on these steps during a motorcade except when necessary. He had repeated this wish only a few days before, during his visit to Tampa, Florida.
The notion that the president's instructions in Tampa jeopardized his security in Dallas has since been denied by Hill and other agents. Regardless of the Warren Commission's findings, photos taken of the motorcade along earlier segments of the route show Hill riding on the step at the back of the car.
As an alternative explanation, fellow agent Gerald Blaine cites the location of the shooting:
We were going into a freeway, and that's where you take the speeds up to 60 and 70 miles an hour. So we would not have had any agents there anyway.
Hill grabbed the handrail less than two seconds after the fatal shot to the President. The driver then accelerated, causing the car to slip away from Hill, who was in the midst of trying to leap onto it. He succeeded in regaining his footing and jumped onto the back of the quickly accelerating vehicle.
As he got on, Mrs. Kennedy, apparently in shock, was crawling onto the flat rear trunk of the moving limousine. Hill later told the Warren Commission that he thought Mrs. Kennedy was reaching for a piece of the president's skull that had been blown off. He crawled to her and guided her back into her seat. Once back in the car, Hill placed his body above the president and Mrs. Kennedy. Meanwhile, in the folding jump seats directly in front of them, Mrs. Connally had pulled her wounded husband, Governor John Connally, to a prone position on her lap.
Agent Kellerman, in the front seat of the car, gave orders over the car's two-way radio to the lead vehicle in the procession "to the nearest hospital, quick!" Hill was shouting as loudly as he could: "To the hospital, to the hospital!" En route to the hospital, Hill flashed a "thumbs-down" signal and shook his head from side to side at the agents in the follow-up car, signaling the graveness of the president's condition.
The limousine then rapidly exited Dealey Plaza and sped to Parkland Memorial Hospital, only minutes away, followed by other vehicles in the motorcade. Hill maintained his position shielding the couple with his body, and was looking down at the president. He later testified:
The right rear portion of his head was missing. It was lying in the rear seat of the car. His brain was exposed. There was blood and bits of brain all over the entire rear portion of 
Clint Hill (Secret Service)