Forensic Pathology for Police - Brainshare Public Online Library

366 13 Gunshot Wound Deaths
Fig. 13.42 Evidence collected from a body that was the victim of a shotgun injury. Note the
presence of a representative sampling of the birdshot pellets, as well as plastic wadding material
Mechanism of Injury
The mechanism of injury in gunshot wound cases mimics those in many other traumatic
causes of death. If the deep central structures of the brain and/or brainstem
are disrupted by the projectile, it is generally accepted that immediate incapacitation
results. Upper spinal cord injury will result in the inability to breath. Brain
injuries that are limited to more peripheral regions can be associated with longer
survival, and perhaps even consciousness, depending on the location of the injury.
Isolated frontal lobe injuries may not induce immediate unconsciousness or incapacitation.
The mass effect associated with the injury and associated swelling can lead
to compression of deeper brain structures and eventual death. In non-central nervous
system sites, deaths frequently result from loss of blood. Other mechanisms,
such as respiratory compromise (lung compression or lungs filling with blood) and
air embolism (resulting from a neck or upper extremity venous injury with subsequent
“sucking” of air into the vein) may also contribute to death. Delayed deaths
can be related to infection, other medical complications (multiple organ failure, systemic
inflammatory response syndrome, sepsis) and deep venous thrombosis due to
pulmonary thromboembolism, to name some possibilities.
Gun enthusiasts and others occasionally become embroiled in discussions regarding
which weapon/ammunition is the best for “stopping” someone. The term
“stopping power” is occasionally used in this regard. Ultimately, the degree of
physical injury sustained by a given tissue/organ is related to the amount of energy
transferred from the projectile to that tissue/organ. Kinetic energy is calculated by
the following formula: KE = 1 / 2 mv 2 (KE: kinetic energy; m: mass; v: velocity). It
should be evident from this formula that the bigger the bullet (that is, the greater the
mass), the more energy it contains. In fact, the amount of energy available to transfer
from a moving bullet is directly proportional to the bullet’s mass. In contrast,
there is an exponential increase in the amount of available energy within a moving