GRIFFIN – FORENSIC SCIENCE BALLISTICS GRIFFIN – FORENSIC SCIENCE

COMPUTERIZED IMAGING

NIBIN National Integrated Ballistics Information Network Produces database files from bullets and cartridge casings retrieved from crime scenes or test fires from retrieved firearms. Multiple crimes NIBIN

Ultimate decision MUST be made with the use of a microscope. Serial Numbers can be restored through chemical etching MICROSCOPIC METHODS

When a firearm is discharged, unburned and partially burned particles of gunpowder in addition to smoke are propelled out of the barrel along with the bullet toward the target. The distribution of gunpowder particles and other discharge residues around a bullet hole allow an assessment of the distance from which a handgun or rifle was fired. GUNPOWDER RESIDUE

GRIESS TEST Chemical test color that can detect nitrite ions. Nitrites react with sulfanilic acid to eventually form a red color.

Barium and antimony are also found in GSR.

BULLET TRAJECTORY

COLLECTION Carefully collect gun. Must prevent accidental discharge – may have to unload. Wrap bullets in tissue paper – place in pill box or envelope. All parts of the gun are recovered and recorded. Marked for identification. Initials of investigator must be etched into all evidence. Chain of Custody must be followed. COLLECTION