Module 4 - Forensic Ballistics

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The assassination of John F. Kennedy, the thirty-fifth President of the United States of America (USA), occurred on Friday, November 22, 1963. Because he was fatally wounded by two gunshots, ballistic evidence was important in the forensic investigation.

The Assassination

President Kennedy was riding in an open-top limousine in a presidential motorcade through Dallas, Texas. The President’s wife (Jacqueline), Texas Governor John Connally, Governor Connally’s wife, and a driver were also in the vehicle. After Kennedy’s limousine slowly passed a building called the Texas School Book Depository, three shots were fired at the limousine from a distance of approximately 60 metres.

As President Kennedy waved to the crowd on his right, the first bullet entered his upper back, exited through his throat, and entered Texas Governor John Connally, penetrating his back, chest, and right wrist. The second bullet missed the vehicle, but the third bullet struck the President in the back of the head. After the three shots, the driver of the President’s limousine sped to a local hospital in a desperate attempt to get emergency medical treatment for the President and the Texas Governor. The President died before arriving at the hospital, and the Governor survived after receiving emergency surgery.

The Investigation

The Dallas Police immediately began searching the area for signs of the assassin. Witnesses claimed the shots came from a nearby building called the Texas Book Depository. Subsequently, police officers found an Italian bolt-action rifle on the sixth floor of the Texas Book Depository. A witness who saw the male assassin fire the last shot from the building gave police a physical description. Police determined that the person that matched the description might be an employee of the Texas Book Depository named Lee Harvey Oswald.

A few hours after the assassination, Dallas Police Officer J. D. Tippit, after hearing the assassin’s description, stopped Oswald on a street corner. When Officer Tippit tried to question Oswald, Oswald shot Tippit four times with a revolver. Oswald fled the scene on foot, and Tippit died from his gunshot wounds. Oswald went into the nearby Texas Theater without paying. The police quickly arrived and arrested Oswald after being notified by theatre staff.

Oswald was questioned for twelve hours about both the Tippit shooting and the assassination of the President. He denied any involvement with the murders. Paraffin tests were performed on Oswald's hands and right cheek for gunpowder residue. The results were positive for the hands and negative for the right cheek.

Two days later as Lee Harvey Oswald was being taken to the Dallas County Jail, he was shot and killed by Jack Ruby before live TV cameras in the basement of Dallas police headquarters.

An official investigation by the Warren Commission conducted in September 1964 concluded that Lee Harvey Oswald was solely responsible for the assassination of President Kennedy.

Internal Ballistic Evidence

The bullet that hit President Kennedy in the head imploded upon impact. As a result, the bullet could not be analyzed for rifling impressions.

However, the bullet that hit Kennedy and Governor Connally was found at the hospital. The bullet was a 6.5 mm round-nose military-style full-metal jacket design specifically meant to pass through the human body. Important pieces of ballistic evidence related to this bullet found by the FBI include the following:

• Neutron Activation Analysis (NAA) of the bullet fragments in Governor Connally’s wrist matched the bullet found.
• The mass of the bullet found was 10.28 g. The average mass of a single, unfired bullet of this type is 10.42 g. The lead fragments retrieved from Connally's wounds in the wrist weighed about 0.13g.
• Rifling impressions found on this bullet matched the lands and grooves in the rifle found at the Texas Book Depository.

External Ballistic Evidence

The muzzle velocities of the bullets that hit President Kennedy were calculated to be between 560 and 610 m/s. Each bullet arced downward while traveling and hit President Kennedy at an angle of 25 degrees from the horizontal.

Terminal Ballistic Evidence

The first bullet that hit the President entered his upper back above the shoulder blade, passed through the base of his neck, bruised the upper tip of his right lung without puncturing it, and exited the front of his neck. The entry point of the bullet was 4 mm by 7 mm in size, and the exit wound was 3 mm by 5 mm. The bullet fractured one of the President’s vertebrae.

Upon leaving the President’s neck, the bullet’s velocity had slowed to about 457 m/s and it had started to tumble. It then hit Governor Connally who was sitting in front of Kennedy. The bullet entered Connally's back creating an 8 mm by 15 mm entry wound. This large entry wound indicates that the bullet was tumbling greatly, which often happens after hitting a target, which was President Kennedy in this case. The bullet destroyed part of one of Connally's ribs as it smashed through his chest leaving an exit wound with a diameter of 50 mm. Slowed to 274 m/s, the bullet entered Connally's upper right wrist depositing metal fragments and exited his palm.

The autopsy of President Kennedy concluded the wound from the second bullet that hit his head was fatal. A small entry wound was visible in the rear right-hand side of the President’s head. The bullet imploded upon impact causing a large portion of the right side of Kennedy’s brain and skull to detach.

Crime Case Study Related Questions

1. Of the two bullets that hit President Kennedy and Governor Connally, why was only one analyzed for ballistic fingerprints?
   Ans.  The bullet that hit the President in the head imploded into fragments upon impact, and therefore, could not be analyzed.
2. What three pieces of ballistic evidence linked the bullet from Connally’s leg to the rifle from the Texas Book Depository?
   Ans. 
   1. NAA of the bullet fragments in Governor Connally’s wrist matched the bullet found.
   2. The mass of the bullet found was 10.28 g and the mass of lead fragments retrieved from Connally's wrist was 0.13 g. The average mass of a single, unfired bullet of that calibre and type is 10.42 g.
   3. Rifling impressions found on this bullet matched the lands and grooves in the rifle found in the Book Deposiory.
3. Answer the following:
   1. How much did the bullet’s velocity change between when it hit Governor Connally in the back to when it entered his wrist?
      Ans.  457 m/s – 274 m/s = 183 m/s
   2. Explain why this change occurred.
      Ans. As the bullet smashed through his flesh and bone (rib), it began losing some of its kinetic energy and slowing.

4. When the first bullet hit President Kennedy, it created a 4 mm x 7 mm entry wound. After it left the President’s body, this same bullet hit Governor Connally creating an 8 mm x 15 mm entry wound. Explain why Governor Connally’s entry wound was so much larger than the President’s entry wound.
   Ans.  As the bullet moved through the President’s neck, it began losing kinetic energy and slowing, causing it to tumble before it hit the Governor. This tumbling caused the Governor’s entry wound to be significantly larger than the President’s entry wound.