Crime Scene Unit Trace Evidence. Evidence Collection Division

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2 Scope Crime Scene personnel are responsible for collecting trace evidence such as hair, fibers, glass, paint, soil, and chemicals present at a crime scene, suspects and/or witnesses. The Medical Examiner s office has jurisdiction over any evidence located on the decedent and will recover it or give permission for it to be recovered by CSI. If trace evidence is seen on a decedent, the CSI is obligated to discuss the evidence with the medical examiner investigator to devise the best manner to ensure its collection Hair and Fiber Evidence Collection Equipment Glassine envelopes Tweezers Razor blade/scalpels Paper envelopes Forensic Light Source Sticky Notes Hinge lifts 1.3. Examination Methods Visual inspection using flashlight with oblique lighting Visual inspection using Forensic Light Source Sample Selection of Unknown Standards On substrates where trace evidence is observed, all unknown samples should be collected 1.5. Collection Methods All evidence should be photographed prior to collection Objects with hair or fiber firmly attached: Carefully collect the entire object, if possible, and package the object in such a way that the hair or fiber will not become dislodged Objects with hair or fiber not firmly attached: Note the location and photograph the hair/fiber in place Carefully remove the hair/fiber using gloved fingers or a pair of tweezers Package the hair/fiber inside a glassine envelope or paper bindle Large Areas (e.g., vehicles/mattresses/floors etc.) A visual search of the area should be conducted first. Uncontrolled When Printed Page 2 of 6

3 Section off the area (e.g. driver s seat, passenger seat, shirt, pants) and use one hinge lifter per area. Each hinge lift should then be properly marked immediately with identifying information Package the hinge lifts from each area individually and in a fully sealed container If the trace evidence is securely attached to an object and cannot be easily removed, then the entire object or portion containing the trace evidence can be collected Collection of Known Standards Crime scene investigators should always consider search and seizure statutes when collecting known standards and whether possible trace evidence (victim s hair, etc.) has been collected beforehand. Identification photos of the subject should be obtained prior to collection and the subject s identifying information noted on the container. The following collection methods should be utilized: Head Hair A representative sample of approximately 10 hairs from each area should be collected The samples should be taken from the top left, top right, center, lower left and lower right sides of the scalp The hair should be pulled as close to the root as possible without stretching the hair If head hair is too short to be pulled, it may be cut as closely to the scalp as possible (with proper notation) Package the hair separately by area inside glassine envelopes or paper bindles Properly mark the package with the appropriate area and information Pubic Hair A representative sample of approximately hairs total should be collected The hair should be pulled as close to the root as possible without stretching the hair Package inside a glassine envelope or paper bindle Properly mark the package with the appropriate area and information Other Body Hair Standards A representative sample of approximately 20 hairs total should be collected from each desired area The hair should be pulled as close to the root as possible without stretching the hair Package the hair separately by area inside glassine envelopes or paper bindles Properly mark the package with the appropriate area and information Uncontrolled When Printed Page 3 of 6

4 Carpet Fiber Standards A representative sample of the carpet should be collected so that the fiber types/colors/wear are represented Include stained/unstained areas and faded/un non-faded areas as well as areas which have different wear patterns and treatment The fibers should be cut as close to the backing as possible Package the fibers separately by area inside glassine envelopes or paper bindles Properly mark the package with the appropriate area and information Glass Collection Crime scene investigators are responsible for collecting glass evidence which may be present at crime scenes, where windows, automobile glass, bottles, and other glass objects have been broken. Glass evidence can assist in the reconstruction of crime scenes Sample Selection On those substrates where glass evidence is observed, unknown samples should be collected at the discretion of the crime scene investigator Collection Methods Objects with glass firmly attached: Carefully collect the entire object and package it in such a way that the glass will not become dislodged Properly package and mark with the appropriate information Objects with glass not firmly attached: Carefully remove the glass using gloved fingers or a pair of tweezers Place the glass inside a glassine envelope or paper bindle Properly package and mark with the appropriate information Clothing/Shoes (e.g. hit and run suspect/victim) Collect the item containing the evidence (shirt, shoes, etc.) Glass evidence on clothing or shoes may be microscopic Wrap each individual item in paper if possible Package in a paper bag and mark with the appropriate information Glass Items (e.g., light bulbs, bottles, etc.) Carefully remove the glass item using gloved fingers Properly package the item in a paper bag within a cardboard box Known Standards For a comparison standard, collect as much as possible of the broken glass If the glass is being used to determine the direction of impact, document which side was outside Package separately from questioned samples. Uncontrolled When Printed Page 4 of 6

5 1.8. Paint Evidence Collection Crime scene investigators are responsible for the documentation and collection of paint evidence which may be present at crime scenes such as homicides and burglaries Sample Selection On those substrates where paint evidence is observed, unknown samples should be collected at the discretion of the crime scene investigator Collection Method Note the location of the paint When possible, collect the entire object and package it in such a way that the paint will not become dislodged When unable to collect the entire object, use a clean scalpel or knife blade to carefully scrape the paint sample into a glassine envelope or paper bindle When collecting a paint sample from a vehicle, a sample from each area of damage should be collected The sample should include all layers down to the bare metal or wood Samples from different areas should be collected and packaged separately Clothing items/shoes (e.g., suspected/possible hit and run victim) with paint transfer should be wrapped in paper first, then placed in a paper bag Known Standards Obtain a known paint sample in close proximity to the unknown sample The sample should include all layers down to the bare metal or wood The sample should be collected and packaged in the same manner as previously mentioned Soil Evidence Collection Crime scene investigators are responsible for collecting soil evidence which may be present at crime scenes such as homicides, sexual assaults, and burglaries Sample Selection On those substrates where soil evidence is observed, unknown samples should be collected at the discretion of the crime scene investigator Collection Methods Soil from impressions Complete casting prior to collection of soil Soil will adhere to the cast. This can be used as your sample. Do not attempt to clean the cast by removing the soil Air dry the cast for 48 hours and ensure the soil is dry Package the cast in a paper container to ensure it will not be damaged Soil from clothing or shoes Uncontrolled When Printed Page 5 of 6

6 Collect the clothing or shoe if possible and wrap each individually in paper Ensure both the clothing/shoes and the soil are dried before packaging Package in paper container and mark it with the appropriate information Unknown soil sample Collect the sample in such a way that it will be allowed to air dry. A recommended method is a paper bindle that can be folded to secure the sample Once the soil is dry, it can be packaged. Mark the package with the appropriate information such as location soil obtained from, date, and name of crime scene investigator collecting the sample Known standards Collect at least three samples of soil (one half to one cup) from each area of interest or under and around the location a victim s body was located, etc Samples should be collected from the top one quarter inch of the surface soil and be representative of the soil types in the area The samples should be collected in such a way that they will be allowed to air dry. A recommended method is a paper bindle that can be folded to secure the sample Once the sample is dry, it can be packaged. Mark the package with the appropriate information to include the location it was collected, the date, and the name of the crime scene investigator that collected the sample References Scientific Working Group on Material Analysis (SWGMAT) Recovery Guidelines Fisher BAJ Techniques of crime scene investigation. 5th ed. New York (NY); Elsevier Science Publishing Co., Inc. Uncontrolled When Printed Page 6 of 6