Firearm Injuries

What can be seen on a X-ray when a high velocity rifle was used?

* "lead snow storm"

Approximately how far does soot travel?

* 12 inches

Most modern handguns will not deposit gunpowder beyond this distance.

* 3 feet

Cylinder gap:

* GP and soot can slip through cylinder gap @ muzzle end

What can be found on clothing around a gunshot wound?

* GP and soot is deposited on clothing * tears in clothing around contact zone * melting -> contact through polyester

What causes the ring of abrasion?

* a bullet scrapes off the epidermis

How much gunpowder soot will be around a close range gunshot wound?

* a lot

What is a Hydra Shok?

* a type of expanding bullet

What is a Perforating gunshot wound?

* a wound where the projectile exits the body

What is a Penetrating gunshot wound?

* a wound where the projectile is still in the body

The skin surround the shored exit wound has a broad area of ____?

* abrasion

Define 1st intention wound healing:

* aka. primary wound healing or primary closure * describes a wound closed by approximation of wound margins or by placement of a graft or flap, or wounds created and closed in the operating room

Define 2nd intention healing:

* aka. secondary wound healing or spontaneous healing * describes a wound left open and allowed to close by epithelialization and contraction.

The severity of wounds depends on the following:

* amount of KE lost in the tissue * angle of yaw of bullet * size of temporary cavity

What defines an intermediary target?

* an object may fragment and strike the person producing various injuries * yaw of the bullet increases producing an atypical entrance wound

What are medical conditions that can result from lead poisoning?

* anemia * seizures * intranuclear inclusions in hepatocytes

Bullet deformation can cause what type of entrance wound?

* atypical entrance wound

Which travels farther a gunpowder ball or disk?

* ball

What are the gunpowder types?

* ball * flattened ball * disk, flake

Bone often indicates direction of bullet by ___?

* beveling (sloping edge)

What do you find with a glaser safety slug?

* blue ball fragments

A bullet might not kill you, but ___ caused by a bull will kill you.

* bone fragments

What part of the body is prone to stellate looking entrance wounds?

* bony prominence of the head

What does lead show up as in the Sodium Rhodizonate Test?

* bright pink

What impacts do intermediary targets have on the bullet?

* bullet deformation -> atypical entrance wound * bullet fragmentation -> more than one entrance wound

How is an old bullet different from a new bullet when found in the victim's body?

* bullet is black and oxidized * scar tissue * is devoid of hemorrhage

Definition of reentrance wound:

* bullet passes through one body part and reenters another body part * exp: arm to thorax

Gutter Wound 3rd degree;

* bullet perforates skull in the center of wound

Keyhole Wounds:

* bullets striking at shallow angle produce a wound with one edge having characteristics of an entrance wound while the other edge has external beveling characteristics of an exit wound

What impact do shotguns have on wounds?

* cause different wound pattern * multiple pellets * buckshot/birdshot/slugs * shot, cup, wad, gunpowder, primer can enter wound

What color is the tissue as a result of a hard contact gunshot wound and why?

* cherry red color * result of carboxyhemoglobin

Range of fire can be labeled as ___?

* close * intermediate * distant

On what type of material is the Greiss Test used on?

* clothing

Gases enter the cranium and expand in what type of wounds?

* contact wounds

When a bullet does not exit/penetrate skin ( lack of kinetic energy) what can be seen?

* contusion (bullet can be felt under skin)

Why can bullets not be extracted from the body with metal instruments?

* damage/alter the striation marks

What is an example for intermediary target?

* doors * windows * other people

The Energy Dispersive x ray test is used for the following:

* edges of entrance analyzed for copper, antimony, barium and lead * not used much in a practical sense, expensive

What can be seen in hard contact gunshot wounds?

* edges of the wound are seared by hot gases and blackened by soot * soot and gunpowder are found within the wound track * thermal injury * muzzle imprint

Define graze wound:

* elongated area of abrasion

What is a homemade silencer?

* empty 2l bottle taped to muzzle of gun

What is a shored entrance wound?

* entrance is supported by another portion of the body * usually seen in reentrance wounds involving arm and chest

What can be determined from a Gunshot Wound?

* entrance vs exit * range of fire * direction of wound path * injured organs * recovery of projectiles

Appearance of exit wounds:

* excavated in cone like manner

Distante range entrance wounds may resemble what kind of other wound type?

* exit wounds * contact wounds

What are examples of pseudo gunpowder soot?

* fingerprint dusting powder * graphite: bullet striking pencils * asphalt: bullet striking ground * powdered lead: bullet fragments (non-jacketed bullet) * dried edges of an entrance wound

Gutter Wound 2nd degree:

* fracture of inner table

Distance range wound:

* fractures produced by pressure from the temporary cavity formation

Secondary fractures are common in contact wounds of the head due to ___?

* gas discharge

Is there a muzzle imprint in loose contact wounds?

* generally not present

What are examples of pseudo gunpowder stipple?

* glass * fragmented bullet * homemade silencer * post mortem insect activity * hemorrhage in hair follicles * sutures and staples * petechiae

Bullet wipe leaves ____rim around an entrance hole.

* gray - black

How does GP show up on light clothing?

* grayish- black

How does GP show up on dark clothing?

* grayish- white

What range is given to a Distance Range Wound?

* greater than 3 feet

Uncoated gunpowder grains appear?

* green or beige

What travels farther, gunpowder or soot?

* gunpowder

Gunpowder tattooing is___?

* gunpowder is embedded in the skin

Gunpowder stippling is____?

* gunpowder leaves abrasion

What can be seen around the wound in a close range of fire scenario?

* gunpowder stiple

Size and density of gunpowder stippling pattern depends on what?

* gunpowder type and barrel length

Contact Gunshot wound types?

* hard contact * loose contact * angled contact * incomplete contact * near contact

What is true to the healing process of exit wounds?

* heal better * 1st intention healing * 2nd intention healing

What type of gun is usually the cause for micro tears?

* high velocity center fire rifle bullets

How is soot removed/wiped off?

* hot water * hydrogen peroxide

Bullet wipe:

* if gun barrel is not clean bullet picks up debris

Gunpowder Stipple:

* impact of unburned , partially burned or burning gunpowder on the skin

Irregular nature of wounds define:

* increase in yaw * bullet deformation

What effect does reentrance wound have on the flight path of the bullet?

* increases the yaw

Define pseudostippling:

* injury to skin not produced by gunpowder * more irregular than stippling

Define tangential wound:

* injury to subcutaneous tissue * area of abrasion at the entrance * torn margins of skin point in the direction the bullet moved

What to keep in mind when finding a decomposed body with some damage looking like a gunshot wound.

* insects can cause "holes" but could not go through bone * look for gunpowder residue

An ____ target is when a bullet passes through a object before the striking person

* intermediary

Ricochet bullets tumble in air producing larger more ___ wounds.

* irregular

What is fluoroscopy?

* is an imaging technique that uses X-rays to obtain real-time moving images of the interior of an object

What can be seen around the wound in a distant range of fire scenario?

* just an entrance wound

What type of wound pattern does a reentrance wound cause:

* large irregular wound * irregular abrasion ring

What type of bullets can result in bullet wipe?

* lead * full jacketed bullets

What does the Sodium Rhodizonate Test detect?

* lead residue * ( most lead arise from primer, some can come from bullet or barrel)

What parts of the body can a bullet emboli to?

* legs * pelvis * rarely brain

How is it determined which bullet strike first?

* less stippling - shot came from distance, victim went down, perpetrator walked up to victim, shot again at close range, causing stippling around second wound

Why are X-rays important in evidence gathering?

* location of bullet and fragments * separation of jacket and core * locate old bullets with scar tissue * lead snowstorm

Contact (range of fire) can be defined as ___?

* loose * tight

Ricochet bullet facts:

* may penetrate but usually do not perforate the body * one surface of bullet is flattened *may fragment and pepper the body

What kind of wound pattern can be seen with bullet fragmentation?

* more than one entrance wound

Near contact facts:

* muzzle close but not in contact with skin * gray zone between contact and intermediate range wounds * overlap in appearance between near and loose contact wounds * too close for gunpowder stipple to be produced

How much pressure is on the skin - loose contact wounds?

* muzzle is in light contact with skin

Angled contact facts:

* muzzle is not in complete contact * gas and soot produce an eccentric pattern * entrance wound is at the base of the eccentric pattern

Close range-intermediate range wounds facts:

* muzzle of gun is away from the body at the time of discharge * muzzle is still close enough to produce gunpowder stippling and possibly soot deposition

Define a Distance Range Wound?

* muzzle of the gun is far enough from body that no soot or gunpowder is deposited on the body

Gunpowder stippling from a close range is ___?

* narrow and more dense pattern ( think hair spray)

What does the Greiss Test detect?

* nitrites ->pop up as orange spots

Are bullet wipe and range of fire related?

* no

Can you determine range of fire in the Sodium Rhodizonate Test as you can in the Greiss Test?

* no

Does Bullet wipe deposit well on skin?

* no

Is tissue lost in exit wounds like it can in entrance wounds?

* no

Will there be stippling on wound with an intermediary object?

* no

Are aluminum bullets easy to see on an X-ray?

* no * aluminum bullets are coated with nylon

Can you estimate a caliber of a bullet from an X-ray?

* no * x-rays alter the size of the bullet, can make them look smaller or larger

What is a sign of a possible bullet emboli?

* no exit wound * but possible could have been aspirated as well

Can gunpowder be wiped away?

* no, becomes embedded in skin

Incomplete contact facts:

* occurs when body surface is not flat * ex: head * elongated area of searing, GP and soot * on side opposite of muzzle

Can range of fire be determined with the Energy Dispersive x ray test?

* only an approximate range

Secondary fractures are most common in what part of the skull?

* orbital plates

Gutter Wound 1st degree:

* outer table grooved by bullet

On what part of the body do you rarely find an abrasion ring?

* palms * soles

Soot contains metals from what parts of the gun?

* primer * bullet * cartridge case

What factors determine soot pattern and range?

* propellant * angle * barrel length * caliber * weapon type

What are pseudo gunpowder stipple?

* punctuate abrasions produced by objects other than gunpowder

Gunshot Wounds to the skull can cause what to the eyes?

* raccoon eyes

Margins of exit wounds can be ____

* reapproximated

Appearance of entrance wounds:

* round, oval * punched out * sharp edged

What defines an entrance wound?

* round, oval, elliptical * ring of abrasion * micro tears * margins CANNOT be re-approximated

If bullets are fired from 5, 50, or 500 feet, they produce the ___ type of entrance wound.

* same

Low velocity bullets may strike the skull, flatten and travel between ____.

* scalp and skull

A bullet coming in with a range of fire and kinetic energy can cause the following:

* secondary fractures * due to intracranial pressure waves

Bone fragments may form ____?

* secondary projectiles

What can you get from a fracture line - skull - bullet hole?

* sequence of bullets * won't jump suture or fracture line

Bullets striking at a ____ may cause a portion of bone to penetrate the brain.

* shallow angle

Coated gunpowder grains appear?

* shiny black

What type of exit wound is the result when skin is supported by a surface when bullet exist?

* shored exit wound

In exit wounds, what does not correlate with type of the bullet?

* size and shape

Skin facts on hard contact GSW?

* skin surrounds muzzle * tearing of skin * surrounding skin blackened by soot

Lax skin in exit wounds appears like:

* slit like

What type of bullets can emboli in the body?

* small caliber * low velocity

A longer barrel causes what type pf soot pattern?

* smaller and denser

Gunpowder facts:

* smokeless * powder grains may be coated or uncoated

Near contact angled wounds facts:

* soot radiates outward from muzzle * bulk of the zone is on the same side as muzzle * opposite of pattern in angled contact wounds

Bullet wipe consists of ___?

* soot, lubricant, metallic elements

What can be seen around the wound in a contact range of fire scenario?

* star shaped * gunpowder deposit

Distant range entrance wounds may appear looking ___

* stellate

Tightly stretched skin in exit wounds appears like:

* stellate

Hard contact gunshot wounds may take on what form?

* stellate * cruciform * gas expands between skin -> pushing it away -> star-shaped

Close range gunshot can lead to what around the bullet entrance on the skin?

* stippling

What parts of the body are prone to lead poisoning with a retained bullet?

* synovial joint * bone * vertebral disc

If it is hard to find an entrance wound in a decomposing body, what can be done?

* take X-ray and find exit wound and work backwards

Injury to subcutaneous tissue is cause by what type of wound?

* tangential wound

What type of wound has an area of abrasion at the entrance wound?

* tangential wound

Gutter wounds:

* tangential wounds that makes a surface furrow without breaking the skin

The variations in the abrasion ring depend on what?

* the direction the bullet entered * concentric - shortening * eccentric - lengthening

What defines a contact gunshot wound?

* the imprint of the barrel on the skin * gases expand the skin around the bullet hole making it appear bigger

In exit wounds what the size and shape depend on?

* the location of the exit wound

What is the Sodium Rhodizonate Test used for?

* to determin bullet defect on clothing not skin

What are the results of the Greiss Test used for?

* to determine range of fire

What can help determine the direction the bullet travelled by looking at the skin/wound?

* triangular pieces of tissue ( apices) will point in the direction bullet is traveling

If there is no soot or gunpowder to determine the range of fire what else can be used to determine the range of fire?

* type of weapon * type of ammunition

How to test if dried edges of an entrance wound have soot or pseudo soot?

* use wet gauze * soot will be picked up, dried skin will not

What is soot?

* vaporized carbon

Bone perforation as a result of a gunshot wound depends on the following:

* velocity of bullet * bullet construction * weight of bullet * angle of interaction between bullet and bone * type of bone

The amount of KE lost depends on the following:

* velocity of bullet * mass of bullet * type of bullet * tissue involved

What is a typical support to result in a shored exit wound?

* wall, ground, chair or tight fitting clothing

When will you not see a cylinder gap on the victim?

* when shooter has revolver close to his body * cylinder gap markings will be on the shooter

Gunpowder stippling from a greater range is ____?

* wider and less dense pattern ( think hair spray)

Define yaw:

* wobbling path of bullet

Cylinder gap can be seen when a revolver is used ____

* wrapping cloth around revolver * L or V shaped blackened area on the cloth

How to find ricochet bullets?

* x-ray during autopsy

Can a bullet emboli in the body?

* yes

Can an abrasion be the result of a bullet traveling under skin and hitting hard objects in the clothes pocket?

* yes

Can bone exit the body after a gunshot?

* yes

Can bone fragments impact the exit wound path?

* yes

Can exit wounds have varying shapes?

* yes

Can soot be wiped away?

* yes

Does bullet wipe come off when going through clothing?

* yes

Is Soot lighter than gunpowder?

* yes

Can the pattern of the intermediary target be imprinted on the bullet?

* yes * ex: screen door

Can you determine the barrel length with a cylinder gap?

* yes * measure the distance between entrance defect and cylinder gap

Can a bullet emboli in a deceased body?

* yes * moving of the deceased body * CPR attempts * CO2 build up

If the organ has no or little connective tissue the temporary cavity will cause more destruction, yes or no?

* yes * brain, liver, spleen

Do exit wounds have abrasions?

* yes but rare

Is it possible to determine an entrance or exit of gunshot on clothing?

* yes, but difficult * if bullet wipe is present, it is an entrance wound

Can someone get lead poisoning from retained bullets?

* yes, but very rare

Can you find soot and gunpowder in loose contact wounds?

* yes, it is deposited in a band around the wound

In what order are the Greiss Test and Sodium Rhodizonate Test performed?

1. Greiss Test 2. Sodium Rhodizonate Test