BALLASTICS TRAUMA TO THE SKULL

1. BALLASTICS TRAUMA TO THE SKULL By Clay Chastain Above: Angry murderer with a ballistic instrument of death.

2. Ballistics is “the science or study of the motion of projectiles, as bullets, shells, or bombs.” In this context, we are focusing on bullets and shells. Ballistics can be divided into three main categories: Handguns (Small caliber) Rifles (Large caliber) Shotguns (Buckshot/Birdshot) Introduction to Ballistics

3. Types of Handguns • There are four main types of handguns: • Single-shot pistols • Derringers • Revolvers (most common handgun variant in the United States) • Auto-loading pistols Above: Single-shot pistol, derringer, revolver, auto-loading pistol

4. Common types are round nose and hollow-point, but other types include semi-wadcutter and wadcutter (designed for target use). Caliber (diameter of bullet) ranges from around .22 to .45 typically. Common traits of handgun ammunition is a relatively low firing velocity (Magnum is slightly below that of a low end rifle). Can have a “jacket” which is a copper coating that reduces lead’s deformation upon entry to a surface. Handgun Ammunition Left: Round nose bullet with full jacket. Below: Hollow-point bullet with jacket.

5. Types of Rifles • There are two main types of rifles: • Rifles (bolt-action, semi-automatic) • Assault rifles (20 round+ and fully-automatic [M16/AK-47 are examples of semi-automatic assault rifles]) Above: Kar98 (bolt-action), Modified M16 Rifle with belt feeder system (full-auto)

6. Almost all rifles use a similar type of bullet which is has a long case and an elongated, somewhat pointed bullet to aid in penetration. Caliber (diameter of bullet) ranges from around .22 to .308 typically. Common traits of handgun ammunition is a relatively high firing velocity (this creates a more circular wound usually). Generally bullets have a jacket that helps to maintain velocity and stability when hitting a surface, leaving enough force to exit the opposite side of the head. Rifle Ammunition Left: Center rifle round, semi-jacketed with Silver-Tip. Left: Traditional assault rifle ammunition.

7. Bullets can deform in two ways: Naturally (on impact) By design (Mushrooming) These scenarios create irregular exit wounds such as large holes or shattering of nearby bone, along with disrupting stereotypical bevels. Bullet Deformation Left (top): A natural deformation of a rifle round after hitting a hard surface. Left (bottom): An engineered bullet which creates a mushroom-shaped hole in soft tissue and the skull.

8. Types of Shotguns • There are many variants of shotguns: • Single-shot • Over-and-under (one on top of another) • Double-barrel (side by side) • Bolt-action • Lever-action • Pump-action • Auto-loading Above: Generic single-shot, SPAS-12 Tactical (Pump-action), Custom over-and-under

9. Can be classified as birdshot or buckshot. Buckshot are larger pellets with more weight; Birdshot are lightweight pellets. Gauge (the maximum weight of a lead ball) – 10,12, 16, 20, 28. Pellets (the solid ball). Birdshot - #11 .06, #10 .07. Buckshot – 4 – 00. Because of weight and velocity, most pellets will penetrate the skull at closer ranges than that of rifles or handguns; many pellets will also bounce around inside the skull, ricocheting from their remaining velocity. Shotgun Ammunition Left: Chart showing relative size of bird/buckshot Left (top): Typical buckshot shell. Left (bottom): Typical birdshot shell.

10. Pellet Ricocheting • It is very common for a pellet to ricochet inside the skull when impacted from a medium to long range shot, creating a degree of brain damage as well as some cranial deformation (ridges and pits).

11. Wound Beveling • Upon impact, wounds will generally exhibit beveling. There are three types: • Inward – At the site of a bullet’s entry. • Outward – At the site of a bullet’s exit. • Reverse – Beveling of the opposite direction on an entry/exit. Right: A standard exit wound bevel on a frontal. Left: A diagram showing a typical bevel in action.

12. Wounds can be classified in four ways: Round, Oval, Keyhole, and Irregular. Round holes are direct angle hits usually from higher velocity sources (although pistols at close range are similar). Oval holes often come from side angle bullets, or incomplete contact wounds. Keyhole wounds occur when a bullet enters at an angle, chipping away bone in a way that resembles an old-fashioned keyhole. Irregular wounds are generally those that come from shotguns or weapons with the force to pulverize bone upon impact. Wound Shape Left (top): A keyhole wound. Left (bottom): The exit and round entry wound.

13. Fractures can be classified in three ways: Radiating, Concentric, and Butterfly. Radiating fractures start from the entry/exit wound and radiate to the weakest area in order to relieve pressure. Concentric fractures are circular rings that form from extreme pressure, such as from rifles. Butterfly fractures are bilateral fractures; however, these fractures are generally on long bones, not the skull. There are also irregular fractures, such as when the trauma is extreme enough to pulverize bone; usually these are secondary or tertiary fractures, unless caused by a shotgun. Fractures Left (top): A radiating fracture dissipating at a suture. Left (bottom): A concentric fracture.

14. Examples of Fleshed Wounds • Many fleshed wounds look similar, however the difference between a rifle wound (left) and the shotgun wound (right) is in the amount of trauma to the skull (pulverization versus shattering).

15. Columbine Reenactment Taken from the Midland Reporter Telegram and the Odessa American newspapers in 2003. Myself, in black, using a TEC DC 9, a 9mm pistol with an extended clip.