Table of Contents
How paraffin test is done?
noun. A forensic test to indicate whether a person has recently fired a gun, in which the person’s hand is coated in hot paraffin wax which cools and sets and is peeled off and tested for the presence of residue from the gun.
What is paraffin cast?
: a test in which a paraffin cast of the hand of a person suspected of firing a gun is subjected to chemical analysis to determine the presence of powder particles.
What kind of evidence is paraffin test?
A paraffin test could establish the presence or absence of nitrates on the hand. However, it cannot establish that the source of the nitrate was the discharge of firearms. Nitrates are also found in substances other than gunpowder.
What is the use of cotton in paraffin casting?
Paraffin wax
| Identifiers | |
|---|---|
| Boiling point | > 370 °C (698 °F) |
| Solubility in water | ~1 mg/L |
| Hazards | |
| Flash point | 200–240 °C (392–464 °F; 473–513 K) |
How is GSR tested?
Gun shot residue is tested by lifting samples off a defendant’s hands or clothing and then testing to see if the lifts contain a fused particle of barium, antimony, and lead, which are known to be present in GSR. A positive GSR test result does not necessarily mean that a defendant has fired a gun.
What is a ballistic examination?
Forensic ballistics involves the examination of evidence from firearms that may have been used in a crime. If investigators recover bullets from a crime scene, forensic examiners can test-fire a suspect’s gun, then compare the marks on the crime scene bullet to marks on the test-fired bullet.
What is GSR gun?
Gun Shot Residue, or simply GSR, is a means of testing for the presence of certain materials on the hands and clothing of a subject in hopes of determining that this individual may have discharged a firearm.
What is the color of positive reaction in paraffin cast?
An organic reagent, diphenylamine, in a concentrated solution of sulfuric acid, is added to the paraffin glove drop by drop. A positive reaction indicating the presence of gunpowder residues is indicated by the appearance of dark blue pin-point specks on the inner surface of the cast.
How is gunshot residue used to solve crimes?
Gunshot residue contains burned particles (potassium nitrite) and some unburned particles (potassium nitrate), and for decades criminal investigators collected these particles by applying melted paraffin wax to a subject’s hands. The development of blue specks was indicative of the presence of nitrates.
What are the three types of ballistics?
The science of projectiles and firearms is defined as ‘ballistics’ and it can be divided into three distinct categories: internal, external and terminal.
How is gunshot residue formed?
Because GSR particles are formed by rapid cooling from extreme temperatures and high pressures, they should contain features of condensates not only on their surfaces, but also within their interiors.