Vaporous Lead Residues
Vaporous lead (smoke) residues are characteristically deposited at closer ranges. These deposits are chemically detectable by an application of the Sodium Rhodizonate Test.
Results are useful in
- determining the maximum distance of the vaporous lead deposits,
- corroborating the results of the Modified Griess Test.
This type of residue is projected from the muzzle of a firearm as a cloud-like array. However, these smoke residues are projected only to a particular maximum distance. This distance can be determined by experimentation using the suspect firearm and ammunition in known-distance test firings.
Residues Consistent with the Passage of a Bullet
Holes found in objects, such as garments, with no accompanying particulate residues may appear consistent with the passage of a bullet. Positive results for the presence of any copper-bearing or lead-bearing residues (bullet wipe) from either or both of the Dithiooxamide Test and the Sodium Rhodizonate Test are consistent with the passage of a bullet.
Residues Consistent with the Discharge of a Firearm
In many instances, the discharge of a firearm will result in the deposit of particulate lead around a bullet hole. This deposit may be in the form of tiny solidified droplets resulting from the surface erosion of a bullet during its passage through the barrel, ejecta from a dirty barrel, or lead shavings from the surface of a bullet.
Such residues may be visible and are chemically detectable. However, these residues are not reproducible and therefore are not useful for a distance determination. On the other hand, they are consistent with the discharge of a firearm.
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