Hello just needd a little help Are gunshot residue and dista

Hello just needd a little help:

Are gunshot residue and distance determination the same? State what the differences are. Explain the difference as if you were explaining it to a jury.

Name three different types of tests that are used for distance determination and state what those tests react with

Solution

Both are different. Due to resudues formed by gunshot we can able to identify the what distance the gun shot take place.

Gun shot residue are chemicals coming out from the gun during firing. During firing gun powder start to burn
and it changes it state from solid to gas. The huge number of gas particles coming out with bullet and hit the target. The gas particles forms a circular residue in the target with bullet at the center.

With this circular residue or diameter of residue we can able to calculate the distance of gunshot.
1. If the target very close to gunshot - residual concentration high but the diameter is low.
2.If the target far from gunshot - residual concentration low but the diameter is scatter with high diameter.

1. Modified Griess Test - Nitrate residue are present around the bullet hit by the target. Based on the diameter
and scatter of nitrate the distance could be identified.

2. Sodium Rhodizonate test - Based on vapour lead this test useful to identify the distance. If the target is hit by
huge distance this methos useful.

3. Dithiooxamide Test - Always there is a friction between bullet and the inside of gun surface when shot take
place. Due to that each gun gives a different mark on the surface of bullet by copper or nickel.