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

reaches the Laboratory, the greater the possibility of conducting useful examinations. It may be necessary to use a variety of techniques to collect suspected body-fluid evidence.
    Collecting Known Samples
    Blood
Only qualified medical personnel should collect blood samples from a person.
Collect at least two 5-mL tubes of blood in purple-top tubes, which contain EDTA as a preservative, for DNA analysis. Collect drug or alcohol-testing samples in gray-top tubes, which contain NaF (sodium fluoride).
Label each tube with the date, time, person’s name, location, collector’s name, case number, and evidence number.
Refrigerate, do not freeze, liquid blood samples (tubes may break if frozen). Use cold packs, not dry ice, during shipping.
Pack liquid blood tubes individually in Styrofoam or cylindrical tubes with absorbent material surrounding the tubes.
Package blood samples from different individuals separately.
Label the outer container “KEEP IN A COOL, DRY PLACE,” “REFRIGERATE ON ARRIVAL,” and “BIOHAZARD.”
Submit to the Laboratory as soon as possible.
    Buccal (Oral) Swabs
Use clean cotton swabs to collect buccal (oral) samples. Rub the inside surfaces of the cheeks thoroughly.
Air-dry the swabs and place in clean paper or an envelope with sealed corners. Do not use plastic containers.
Identify each sample with the date, time, person’s name, location, collector’s name, case number, and evidence number.
Package oral samples from different individuals separately.
Buccal samples do not need to be refrigerated.
Submit to the Laboratory as soon as possible.
If a reference blood or oral sample cannot be obtained, an alternate reference sample may be submitted (for nuclear examinations only). This may include such items as surgical samples, Pap smear slides, pulled teeth, or a toothbrush or item of clothing known to be used solely by the individual of interest.
    Blood on a Person
Absorb suspected liquid blood onto a clean cotton cloth or swab. Air-dry the cloth or swab and pack in clean paper or an envelope with sealed corners. Do not use plastic containers.
Absorb suspected dried blood onto a clean cotton cloth or swab moistened with distilled water. Air-dry the cloth or swab and pack in clean paper or an envelope with sealed corners. Do not use plastic containers.
    Blood on Surfaces or in Snow or Water
Absorb suspected liquid blood or blood clots onto a clean cotton cloth or swab. Air-dry the cloth or swab and pack in clean paper or an envelope with sealed corners. Do not use plastic containers.
Collect suspected blood in snow or water immediately to avoid further dilution. Eliminate as much snow as possible. Place in a clean, airtight container. Freeze the evidence and submit to the Laboratory as soon as possible.
    Bloodstains
Air-dry suspected wet bloodstained garments. Wrap dried bloodstained garments in clean paper. Do not place wet or dried garments in plastic or airtight containers. Place all debris or residue from the garments in clean paper or an envelope with sealed corners.
Air-dry small suspected wet bloodstained objects and submit the objects to the Laboratory. Preserve bloodstain patterns. Avoid creating additional stain patterns during drying and packaging. Pack to prevent stain removal by abrasive action during shipping. Pack in clean paper. Do not use plastic containers.
When possible, cut a large sample of suspected bloodstains from immovable objects with a clean, sharp instrument. Pack to prevent stain removal by abrasive action during shipping. Pack in clean paper. Do not use plastic containers.
Absorb suspected dried bloodstains on immovable objects onto a clean cotton cloth or swab moistened with distilled water. Air-dry the cloth or swab and pack in clean paper or an envelope with sealed corners. Do not use plastic containers.
    Blood Examination Request Letter
    A blood examination request letter must contain the following information:
A brief statement of facts relating to the case.
Claims made