3 inches, 12 inches, 18 inches greater than 3 inches but less than 18 inches.
No GSR on skin because all GSR is inside the body
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
GSR When gases combust Propel bullet Blow out from ejector port and muzzle GSR Ejector particles Combustion residue Unburned powder particles
GSR – travel 3 – 5 feet As firearm gets closer – the residue concentrations increase
Elements contained in GSR are not water soluble therefore the residue will remain on clothing
Greiss Test Performed 1st does not interfere with later tests Detects nitrites (product of combustion) Used to determine muzzle to garment distance
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
Steps continued Acetic acid will react with nitrites and chemicals in photographic paper Resulting in orange specks
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
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
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
GSR results - 3 categories Residue, firearm and ammunition found Residue found – firearm and ammunition not found Trace or no residue found
Gunshot wounds are typically classified as Contact Intermediate range Distant range
Contact barrel contacts the skin the gases released cause the star-shaped laceration.
ContactThe abrasion ring, and a very clear muzzle imprint, are seen in this contact range gunshot wound.
intermediate Powder tattooing The actual entrance site is somewhat irregular, because the bullet can tumble in flight.