High Velocity Projectile Trauma (Lab 13) Flashcards
What is the primary factor that distinguishes high velocity projectile trauma from other types of trauma in forensic contexts?
The velocity of the projectile
How does the presence of lead residue or bullet fragments assist in identifying high velocity projectile trauma?
It is diagnostic of high velocity projectile trauma
In the context of projectile trauma, what is the significance of secondary and tertiary fractures?
They show the amount of energy imparted to the body
What is the primary task of a forensic anthropologist when analyzing projectile trauma?
Describing the evidence of trauma on the skeleton
what is NOT considered an intrinsic factor affecting skeletal trauma?
The type of bullet fired
__________ size is measured by caliber, where larger numbers indicate larger bullet diameters (.22, .45, 9 mm)
Ammunition
_________ are measured by gauge; a smaller number indicates a larger diameter of shell (12 gauge = 1/12 pound ball would fit in the diameter of the barrel).
shotgun shells
burned gunpowder is discharged resulting in ______ around the wound; this can be washed away
soot
Second, ________ are ejected from the end of the barrel, which can indent the soft tissue before the bullet arrives or be driven into and under the skin causing a plastic deformation to the wound site similar to over-inflating and then deflating a balloon.
gases
firing a bullet produces _______, which can cause burns on the skin if the end of the barrel is pressed against the body.
heat
unburned gunpowder is discharged, which travels farther than burned gunpowder because it is heavier. This impacts the skin causing abrasions in the form of _________ or ____________
stippling or powder tattooing.
__________ wounds result from when the barrel of the gun is placed firmly and completely against the body. When fired, the bullet is propelled along with gases, burned, and unburned gunpowder into the wound itself
There is evidence of burning around the wound from the barrel touching the skin, but little evidence of soot or stippling around the wound.
hard contact
The gases can cause ___________ (star-like in appearance) of the skin around the primary wound site.
stellate tearing
With ___________ wounds the barrel is not placed completely against the body. There is no stellate (starlike appearance) tearing because the projected gases dissipate around the end of the barrel instead of being forced into the body.
loose contact
With close range gunshots
the farther away the barrel is from the body the greater the spread of soot and unburned gunpowder will be around the primary wound.
unburned gunpowder will generally not be present if shot from more than 7 inches away. This means close range gunshots with soot (can be removed with water) and stippling (cannot be removed with water) will be in the range of 1-6 inches. Close range gunshots without soot but with stippling will be in the range of 7-24 inches. Gunshots without burning, stellate tearing, soot, or stippling will be from greater than 24 inches away. This is called a distance wound.
Close range gunshots cause more damage than distance gunshots. Larger caliber weapons cause more damage than smaller caliber weapons. Bullets that fragment or deform and stay in the body cause more damage than those that exit the body because all of their kinetic energy is released into the person’s tissues.
As bullets pass through the body they cause beveling within the wound, where the beveling points in the direction the bullet is moving. As the bullet enters the skull it will cause a wound that will be larger on the inside surface of the skull than on the outside surface of the skull (inward beveling).
As the bullet exits the skull it will cause a larger wound on the outer surface of the skull than on the inner (outward beveling).
______________ refers to the primary impact site of a bullet and is usually described as round, oval, square, or irregular.
wound shape
The shape of the bullet wound is determined by two primary factors: 1) the angle of impact (perpendicular to the bone or at an angle), and 2) the bullet’s rotational behavior as it impacts the body.
A bullet with enough velocity to maintain its rotation around its long axis that impacts at a right angle will create a ________ bullet hole with __________ wound beveling.
round
symmetrical
Bullet wounds that are _______ indicate the bullet was wobbling on its axis as it impacted the body.
oval
An ________ bullet wound indicates it was tumbling upon impact, suggesting a deflection. Because bullets lose velocity with distance, an irregular- or oval-shaped bullet wound may be useful in a forensic investigation for directing areas of search for additional evidence (gun casings) or comparing against a suspect’s sworn statements.
irregular
_________ combine an entrance and exit wound in the same impact site, they indicate the direction the bullet was traveling and the position of the assailant with respect to the victim
key hole
_______________- are a special class of bullet wound defined by their shape. these wounds result from a bullet impacting the skull at a shallow angle, which fractures the bullet into 2 or more fragments. These fragments have separate trajectories depending on the angle of impact and can create an entrance and exit wound at the same impact site
keyhole wounds
___________ or ________ fractures originate from the primary fracture site and radiate out as a means of dissipating the bullet’s energy
Secondary or radiating fractures
_________ or __________ surround the bullet impact site and dissipate any remaining energy after the formation of radiating fractures.
Tertiary or concentric fractures
The physical separation of the suture line caused by the energy traveling through it is called a
diastatic fracture
__________ fractures radiate out from the primary impact site, which means their course can be traced back to the bullet impact location. In cross-section, these fractures show no beveling (unlike primary impact sites) and the fracture lines form perpendicular to the outer and inner surfaces of the vault.
radiating fractures
___________ fractures result from a high amount of energy impacting the body resulting in the formation of fracture lines that form a circle (often only partial) around the primary bullet impact site. They develop as a result of an increase in intra-cranial pressure caused by the bullet impact, which results in the bone surrounding the primary impact site to heave outward
Concentric
Which type of fracture is indicative of a perpendicular impact on a long bone during blunt force trauma?
butterfly fracture
How do concentric fractures differ between blunt force trauma and projectile trauma?
Concentric fractures in blunt force trauma are internally beveled, while in projectile trauma they are externally beveled.
What is the significance of striations in sharp force trauma analysis?
They indicate the direction of movement of the weapon with respect to the bone.
How can injury recidivism be identified in forensic analysis?
By documenting a pattern of repeated blunt force trauma over time.
