Bullet holes are smaller than bullets due to fabric elasticity. Higher velocity bullets cause greater damage. Bullet wipe leaves a ring of lead residue. Gunshot residue contains ejector particles and combustion/unburned powder particles that travel up to 5 feet from the firearm. The Greiss test detects nitrites from combustion using treated paper placed on samples, revealing orange specks. The sodium rhodizonate test confirms the presence of lead through a pink then blue color change. Gunshot residue examinations can determine the firing range and presence of the firearm and ammunition.

2. Bullet Holes
 The bullet holes are smaller in diameter than the bullet
due to the elasticity of the fabric
 Higher the velocity = the greater the damage
 Bullet wipe residue – traces of lead leave a ring of residue

3. GSR
 When gases combust
 Propel bullet
 Blow out from ejector
port and muzzle
 GSR
 Ejector particles
 Combustion
residue
 Unburned powder
particles

4.  GSR – travel 3 – 5 feet
 As firearm gets closer – the residue concentrations
increase

5.  Elements contained in GSR are not water soluble
therefore the residue will remain on clothing

6. GSR Examinations
 Visual/Microscopic Examination
 Greiss Test
 Sodium Rhodizonate

7. Greiss Test
 Performed 1st does not interfere with later tests
 Detects nitrites (product of combustion)
 Used to determine muzzle to garment distance

8. Steps of Greiss Test
 Treat photographic paper with chemical mixture – paper will
no longer be light sensitive but will be reactive to the
presence of nitrite residues
 Particle being processed placed faced down against treated
photo paper – bullet hole centered
 Steam ironed - dilute acetic acid

9. Steps continued
 Acetic acid will react with nitrites and chemicals in
photographic paper
 Resulting in orange specks

10.  Using same firearm – make test samples from various
distances
 Determine
 Minimum firing distance (the gun could be no closer than)
 Maximum firing distance (the gun could be not any further
than

11. Greiss Test – 3 inches

12. Greiss Test – 9 inches

13. Greiss Test – 15 inches

14. Greiss Test – 21 inches

15. Sodium Rhodizonate Test
 Determines if lead residues are present
 Spray particle with sodium rhodizonate solution (dark
yellowish/orange color)
 Sprayed with buffer solution – causes background color to
disappear

16. Sodium Rhodizonate Test
 Sodium rhodizonate reacts with lead – very bright pink
 Pink – only indication of presence of lead
 To confirm – area treated with Hydrochloric acid
 If pink turns blue – presence of lead confirmed

17. GSR results - 3 categories
 Residue, firearm and ammunition found
 Residue found – firearm and ammunition not found
 Trace or no residue found

19. Gunshot wounds are typically classified as
 Contact
 Intermediate range
 Distant range

20. Contact
 barrel contacts
the skin
 the gases
released cause
the star-shaped
laceration.

21. Contact
The abrasion
ring, and a very
clear muzzle
imprint, are seen
in this contact
range gunshot
wound.

22. intermediate
 Powder tattooing
 The actual entrance site
is somewhat
irregular, because the
bullet can tumble in
flight.