Read FBI Handbook of Crime Scene Forensics for Free Online Page A

bullet was fired from that firearm.
    Cartridge Cases or Shotshell Casings
    Cartridge-case or shotshell-casing examinations can determine the caliber or gauge, the manufacturer, and whether there are marks of value for comparison. The images of questioned cartridge cases and shotshell casings can be scanned into the National Integrated Ballistic Information Network (NIBIN) to compare with evidence from other shooting incidents. The microscopic characteristics of evidence cartridge cases and shotshell casings can be examined to determine whether they were fired from a specific firearm.
    Shot Pellets, Buckshot, or Slugs
    Examinations of shot pellets, buckshot, or slugs can determine the size of the shot, the gauge of the slug, and the manufacturer.
    Wadding
    Examinations of wadding components can determine the gauge and the manufacturer.
    Unfired Cartridges or Shotshells
    Examinations of unfired cartridges or shotshells can determine the caliber or gauge and whether there are marks of value for comparison. Examinations also can determine whether the ammunition was loaded in and extracted from a specific firearm. Unfired and fired cartridges or shotshells can be associated through manufacturing marks.
    Gunshot Residue on Victim’s Clothing
    The deposition of gunshot residue on evidence such as clothing varies with the distance from the muzzle of the firearm to the target. Patterns of gunshot residue can be duplicated using a questioned firearm-and-ammunition combination fired into test materials at known distances. These patterns serve as a basis for estimating muzzle-to-garment distances.
    Gun Parts
    Examinations of gun parts can determine the caliber and model of the gun from which the parts originated.
    Silencers
    Muzzle attachments can reduce the noise of a firearm by suppressing sound during firing. Testing can determine whether a muzzle attachment can be classified as a silencer based on a measurable sound-reduction capability.
    Questions on ern n firearm ea en evidence should be directed to 703-632-8442. Follow the evidence submission directions, including Requesting Evidence Examinations and Packaging and Shipping Evidence .
All firearms must be unloaded.
The firearm should be submitted. If the firearm cannot be submitted, call 703-632-8442 for instructions.
The firearm must be handled minimally to avoid loss or destruction of evidence. Do not allow objects to enter or contact the firearm’s barrel, chamber, or other operating surface.
Firearms and ammunition components such as bullets, cartridge cases, and shotshell casings can be sent via Registered Mail through the U.S. Postal Service. Evidence must be packaged separately and identified by date, time, location, collector’s name, case number, and evidence number.
U.S. Department of Transportation regulations and the following guidelines must be followed when shipping live ammunition :
Package and ship ammunition separately from firearm(s).
The outside of the container must be labeled “ORM-D, CARTRIDGES, SMALL ARMS.”
The Declaration of Dangerous Goods must include the number of package(s) and the gross weight in grams of the completed package(s).
Do not mark the firearm. Firearms must be identified with a tag containing the caliber, make, model, and serial number. The date, time, name(s) of the owner(s), location, collector’s name, case number, and evidence number must be on the container.
Do not mark bullets, cartridges and cartridge cases, shotshells and shotshell casings, or other firearm-related evidence. The date, time, location, collector’s name, case number, and evidence number must be on the container.
Clothing submitted for gunshot residue examination must be carefully handled, air-dried, and wrapped separately in paper. Clothing with blood must be air-dried and labeled “BIOHAZARD” on the inner and outer containers. The date, time, location, collector’s name, case number, and evidence number must be on the container.
    Forensic Facial