This article deals with gunshot wounds, which are seen by (forensic) pathologists in the context of forensic autopsies.
An introduction to forensic pathology is in the forensic pathology article.
- 1 Bullet accounting
- 2 "Sites of election" (suicide)
- 3 Firearm projectiles
- 4 Entrance wounds
- 5 Exit wounds
- 6 Special entrance/exit wounds
- 7 Distance of shooter
- 8 Injury severity due to GSWs
- 9 See also
- 10 References
Number of entrance wounds should equal the number of exit wounds.
If the above is not so... the explanation is:
- Bullets are still in the body.
- "Tandem bullets" -- two bullets entered (or exited) at the same place.
- Secondary projectile -- a bullet hit something, e.g. bone, and made it fly out of the body.
- Pathologist missed an entrance or exit.
- Places to look:
- Below chin (common in suicides).
- In the mouth (common in suicides).
- Places to look:
"Sites of election" (suicide)
Common places where people shoot themselves:
- Left chest.
- Below the chin.
- Bullets are often good evidence:
- The calibre (size) and markings from the barrel (on handgun/rifle projectiles) allow it to be matched to the weapon that fired it.
- Thus, all projectiles are recovered from a body... and it is routine to X-ray all gunshot victims.
Two broad groups:
- Shotgun projectiles.
- Buckshot - usu. 7-9 pellets, typically 6-9 mm (diameter).
- Birdshot - many pellets, typically 2-5 mm (diameter).
- Slug - one large bullet; may be confused with a (high power) rifle projectile.
- Handgun/rifle projectiles.
- Similar in size to the barrel - large when compared to shotgun projectiles.
- Bullets from handguns/rifles are marked by the barrel on the way-out (by grooves which in part spin on it to improve accuracy).
- Rifled projectile are often group by diameter, e.g. "22 caliber" is 0.22 inches (~5.6 mm).
- Circular/round defect --especially if the projectile strikes at a right angle to the surface.
- If the projectile strikes at an angle the injury will be elliptical and the long axis of the ellipse will lie approximately in the plane the bullet traveled.
- An abrasion, or scraping, --concentric or eccentric-- usually surrounds a deep wound (key feature -- used to differentiate from exit wounds).
- Eccentric abrasion suggest directionality.
- Usually smaller than exit wounds.
- In skull the inner table defect is typically larger than outer table defect ("internal bevel").
Atypical entrance wounds
- Irregular (non-circular/non-elliptical) margin.
- May be due to close range/contact.
- Classically results in a "stellate" pattern.
- Bullet ricochets --hits other object before hitting target, gun defective -- bullet's long axis doesn't coincide with its velocity vector.
- Classically results in a "D-shaped" wound.
- May be due to close range/contact.
Ceramic plates (experimental)
- Usually bigger than entrance wounds.
- Morphologic shape -- variable/irregular.
- May be : stellate, ovoid, round.
- Looks like it may be easily approximated with sutures -- unlike a typical entrance wound.
- NO abrasion at wound margin - key feature.
- In skull -- outer table defect typically larger than inner table defect (external beveling).
Atypical exit wounds
"Shored" exit wounds:
- Exit defect created whilst surface supported/adjacent to firm surface.
- Supporting surface may lead to abrasion.
- May appear to be an entrance wound.
Special entrance/exit wounds
- Combination entrance/exit wounds -- result from a bullet grazing the victim.
- Attached skin tags can give directionality; they are classically found at the aspect of the wound distant from the projectile's origin.
- The University of Utah describes it as:
- Characteristically, the side of the [skin] tag demonstrating a laceration is the side of the projection toward the weapon.
Distance of shooter
- Muzzle impression.
- Stellate splitting/tearing of the skin -- especially if it overlies a bony surface.
- Soot/gun powder residue - deep in the wound.
- Stippling (tattooing) - punctate abrasions around the entrance wound.
- Suggests a distance > 1 cm and <= 60 cm (rim fire cartridge), > 1 cm and <= 90-120 cm (centrefire cartridge).
- Soot/gun powder residue - dirt at the entrance, can be wiped-off.
- Scalloped border/edge in shotgun wound.
- No soot.
- "Satellite" wounds.
- Wad marks - typically have sharp edges +/- sharp corners.
- Previously known as distant for non-shotguns, as this is the pattern seen if a shooter is far from the victim.
- No soot.
- No stippling.
- Absence of soot & stippling does not exclude near range; the lack of soot and stippling may be explained by clothing or an intermediate target that the projectile travelled through prior to striking the victim.
- Intermediate should not be confused with indeterminate.
Summary table - hand gun entry wounds:
|Contact||+/- (only if to head)||+ (in wound)||+ (in wound)||muzzle imprint|
|Near contact||-||+ (in & around wound)||+||no muzzle imprint|
|Intermediate||-||-||+||should not be confused with intermediate target|
|Indeterminate||-||-||-||previous known as distant|
Summary table - shot gun entry wounds:
|Distance||Skin splitting||Soot||Stippling||Projectile topography||Wad mark|
|Contact||+/- (only if to head)||+ (in wound)||+ (in wound)||round||-|
|Near contact||-||+ (in & around wound||+ (in & around wound)||round with scalloped border||-|
|Intermediate||-||-||+||round with scalloped border + "satellite" bullets||+/-|
|Distant||-||-||-||scattered, multiple round-same size||-|
Injury severity due to GSWs
The damage of a projectile depends on:
- Where the bullet strikes, e.g. ascending aorta vs. brain vs. tibia vs. gluteus maximus.
- Kinetic energy of the bullet.
- Velocity is more important -- as it is squared (duh).
- Cavitation effect; temporary cavity formation.
- Rouse D, Dunn L (September 1992). "Firearm fatalities". Forensic Sci. Int. 56 (1): 59–64. PMID 1398378.
- DiMaio, Vincent J.M.; Dana, Suzanna E. (2006). Handbook of Forensic Pathology (2nd ed.). CRC Press. pp. 147. ISBN 978-0849392870.
- Denton JS, Segovia A, Filkins JA (September 2006). "Practical pathology of gunshot wounds". Arch. Pathol. Lab. Med. 130 (9): 1283?9. PMID 16948512. http://journals.allenpress.com/jrnlserv/?request=get-abstract&issn=0003-9985&volume=130&page=1283.
- Dixon, DS. (Jan 1984). "Determination of direction of fire from graze gunshot wounds of internal organs.". J Forensic Sci 29 (1): 331-5. PMID 6699600.
- URL: http://library.med.utah.edu/WebPath/TUTORIAL/GUNS/GUNINJ.html. Accessed on: 6 March 2012.
- DiMaio, Vincent J.M.; Dana, Suzanna E. (2006). Handbook of Forensic Pathology (2nd ed.). CRC Press. pp. 135. ISBN 978-0849392870.
- DiMaio, Vincent J.M.; Dana, Suzanna E. (2006). Handbook of Forensic Pathology (2nd ed.). CRC Press. pp. 139. ISBN 978-0849392870.
- Maiden N (2009). "Ballistics reviews: mechanisms of bullet wound trauma". Forensic Sci Med Pathol 5 (3): 204–9. doi:10.1007/s12024-009-9096-6. PMID 19644779.