Trauma affects the skeleton via fracturing and dislocating the bones, which would disrupt the blood and nerve supply. Studying the osteological trauma can possibly tell the violence happened. There are three types of fractures: traumatic fracture, pathologic fracture, and periprosthetic fracture. Among these, we are going to discuss traumatic fracture, particularly from projectile trauma here with reference to the real case I encountered in the morgue.
The deceased was a male, in late twenties or early thirties. He expired at 6 am and two hours later, he is with us in the morgue. According to the death investigator back from the crime scene, he attempted to kill his girlfriend and suicide. His girlfriend survived, but not him.
Externally, there is one bullet hole on each side of the skull. According to the external condition, it is possible that the wound on the right would be the entrance wound, and the left would be the exit wound. Yet, it is the otherwise when we have shaved his hair and opened up the skull.
After shaving his hair however, the beveling is really clear. Judging from the projectile fracture and the beveling, the exit wound would be on the right and the entrance would be the wound on the left.
Trajectory of the projectile, usually gunshot wounds, can be located and identified as either penetrating when no exit wound is found, or perforating that a projectile has an entrance and exit like the captioned case. Crime investigation unit will usually use color stick to link the trajectory for verification. Speaking of beveling, a skull contains layers—inner and out table. The force of the projectile would impact differently on the layers, and caused differences performances on entrance and exit spot. Generally speaking, when a bullet enters it produces a sharp-edged on the outer surface of the skull, but “beveled-out” on the inner surface, and this is called internal beveling.
Internal beveling (Source: the University of Tennessee, Department of Anthropology)
External beveling is usually seen on the exit wound—the outer surface beveled out. Yet occasionally would also be seen on the entrance site, depends on the way of holding the projectile and the distance of the projectile from the head. There is also one condition called the keyhole, which would only be seen when the entrance and exit wound overlapped.
External beveling (Source: the University of Tennessee, Department of Anthropology)
Keyhole wound (Source: the University of Tennessee, Department of Anthropology)
So, the entrance wound for this case is on the left and the exit on the right, does it mean the deceased is left-handed? According to the M.E., he stated that there are indeed studies done and show that no relevance with hand preferences to pull the trigger.
The M.E. also pointed out that sometimes blunt force and projectile force trauma may not directly fatal. The energy from the trauma could be transmitted and make the brain tissue hit on the foramen magnum that creates a second wave of trauma. That would delay the death a little.
Also, on the other case that another M.E. was working on, they found negative results from autopsies on cause of death. They found only hemorrhage in his brain but the skull did not fracture at all. He decided to open up the deceased at the back and see if they can trace fractures, possibly compression fracture on the neck and the spine that would cause instant death, and the autopsy later confirmed this manner of death.