FBI Handbook of Crime Scene Forensics (3 page)

• Blood/saliva (reference samples).
  
  • Refrigerate, do not freeze, liquid blood samples.
    
  • Store refrigerated, frozen (if dried), or at room temperature, away from light and humidity.
    
• Blood/semen (evidence samples).
  
  • Store refrigerated, frozen, or at room temperature, away from light and humidity.
    
• DNA tubes/tissue samples, etc.
  
  • Store refrigerated or frozen, if possible.
    
  • It is recommended that these samples be stored in a refrigerator/freezer and isolated from evidence that has not been examined.
    

Examinations of commercial electronic devices—including personal digital assistants (PDAs), cellular telephones, pagers, and global positioning systems (GPSs)—can extract user- or owner-entered data and other information. In some cases, it is necessary to disassemble the devices during examination.

Interception-of-communication (IOC) devices are used to unlawfully intercept oral or wire communications. The devices consist of radiofrequency transmitters and receivers. Examinations are conducted to identify operating characteristics (frequency of operation, range of operation). In some cases, it is necessary to disassemble the devices during examination.

Examinations on other electronic devices and circuitry—including facsimile machines, stun guns, and bomb detonators—can extract user- or owner-entered data, stored data, and other information. The examinations can identify operating characteristics and modifications made to the devices. In some cases, it is necessary to disassemble the devices and/or circuits during examination.

Questions concerning electronic device examinations should be directed to 703-985-2400. Questions concerning shipping electronic device evidence should be directed to 703-985-1388. FBI entities may refer to the Operational Technology Division/Digital Evidence Section web page on the FBI intranet for additional information regarding evidence submission.

Follow the evidence submission directions, including
Requesting Evidence Examinations
and
Packaging and Shipping Evidence
.

• Label the outer container “FRAGILE, SENSITIVE ELECTRONIC EQUIPMENT” and “KEEP AWAY FROM MAGNETS OR MAGNETIC FIELDS.”
  
• Address the outer container as follows:
  

  FORENSIC PROGRAM
  BUILDING 27958A
  ENGINEERING RESEARCH FACILITY
  FEDERAL BUREAU OF INVESTIGATION
  QUANTICO VA 22135
  

Firearm examinations can determine the general condition of a firearm and whether the firearm is mechanically functional or in a condition that could contribute to an unintentional discharge. Triggerpull examinations can determine the amount of pressure necessary to release the hammer or firing pin of a firearm. Examinations can determine whether a firearm was altered to fire in the fullautomatic mode. Obliterated and/or altered firearm serial numbers sometimes can be restored. Firearms can be test-fired to obtain known specimens for comparison with evidence ammunition components, such as bullets, cartridge cases, and shotshell casings.

Comparisons of suspect firearms can be made with firearms depicted in surveillance images, possibly resulting in an “association” conclusion. Photogrammetry can determine the length of the weapon(s) used by the subject(s) depicted in the surveillance images. See
Image Analysis Examinations
.

Fired bullets can be examined to determine general rifling characteristics such as caliber, physical features of the rifling impressions, and the manufacturer of the bullets. The microscopic characteristics on evidence bullets can be compared with test-fired bullets from a suspect firearm to determine whether the evidence bullet was fired from that firearm.

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.

Examinations of shot pellets, buckshot, or slugs can determine the size of the shot, the gauge of the slug, and the manufacturer.

Examinations of wadding components can determine the gauge and the manufacturer.

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.

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.

Examinations of gun parts can determine the caliber and model of the gun from which the parts originated.

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.
  

• Submit samples of glass from each broken window or source in leakproof containers such as film canisters or plastic pill bottles. Do not use paper or glass containers.
  
• Submit samples of laminated glass (e.g., windshield) from each side of the glass. Label the samples “INSIDE” and “OUTSIDE” and package separately in leakproof containers such as film canisters or plastic pill bottles. Do not use paper or glass containers.
  
• Submit the air-dried clothing of the victim(s) and suspect(s). Package each item separately in a paper bag.
  
• Search for particles in the hair, skin, and wounds of the victim(s) and suspect(s). Submit particles in leakproof containers such as film canisters or plastic pill bottles. Do not use paper or glass containers.
  
• Search for particles in vehicles by vacuuming each section of the vehicle separately. Do not use tape for recovering glass particles. Submit vacuum sweepings in leakproof containers. Do not use paper or glass containers.
  
• Ship known and questioned debris separately to avoid contamination.
  
• Do not process evidence for latent prints.
  

• Label the sides of the glass in the frame (“INSIDE” and “OUTSIDE”). Label the glass where it was removed in the frame (“TOP,” “BOTTOM,” “LEFT,” and “RIGHT”).
  
• Submit all glass pieces so that the pieces can be fit together to identify the radial cracks near and at the point(s) of impact and to increase the probability of matching edges. Pack all glass separately and securely to avoid shifting and breaking during shipping.
  
• Submit the entire piece of laminated glass, if possible. Secure the glass between sheets of plywood or sturdy cardboard. Do not place any objects into the impact area.
  

Do not process evidence for latent prints.