Free FBI Handbook of Crime Scene Forensics by Federal Bureau of Investigation

submit the ribbon to the Laboratory. Insert a new ribbon in the typewriter prior to obtaining exemplars.
If the typewriter has a fabric ribbon, remove it from the typewriter and put the typewriter in the stencil position. Place a sheet of carbon paper over a sheet of blank paper and insert both into the typewriter. Allow the typeface to strike the carbon paper. Submit the fabric ribbon and the exemplars typed on the carbon paper to the Laboratory.
Obtain two full word-for-word typed exemplars of the questioned text and two typed exemplars of the entire keyboard (all symbols, numbers, and upper- and lowercase letters).
Record the make, model, and serial number of the typewriter on the exemplars. Also record the date the exemplars were obtained and the name of the person who typed the exemplars.
Obtain the typewriter service and repair history, if available.
Normally it is not necessary to send the typewriter to the Laboratory; however, in some cases, the examiner will request the typewriter. It must be packed securely to prevent damage during shipment. Typewriter elements (e.g., ball, printwheel, or thimble) also must be submitted to the Laboratory.
    Photocopies or Facsimiles
    Photocopies or facsimiles of documents can be identified with the machine used to produce them if the exemplars and questioned documents are relatively contemporaneous. The possible make and model of the photocopier or facsimile machine sometimes can be determined.
    Procedures for Obtaining Known Photocopy Exemplars
Obtain at least 10 exemplars without a document on the glass plate and with the cover down.
Obtain at least 10 exemplars without a document on the glass plate and with the cover up.
Obtain at least 10 exemplars with a document on the glass plate and the cover down.
Obtain at least 10 exemplars with a document through the automatic document feeder, if applicable.
Record on each exemplar the date the exemplars were obtained, the name of the person who prepared the exemplars, and the conditions under which the exemplars were made.
Record the make, model, and serial number of the photocopier; information about the toner supplies and components; whether the paper supply is sheet- or roll-fed; and options such as color, reduction, enlargement, zoom, mask, trim, and editor board.
Do not store or ship photocopies in plastic envelopes.
    Graphic Arts (Commercial and Office Printing)
    Printed documents can be associated with a common source or identified with known commercial printing paraphernalia such as artwork, negatives, and plates or office printing devices such as ink-jet or laser printers.
    Paper
    Torn edges can be compared. The paper manufacturer can be determined if a watermark is present. Paper can be examined for indented writing. Do not rub the indentations with a pencil. Do not add indentations by writing on top of the evidence.
    Burned or Charred Paper
    Burned or charred documents (not completely reduced to ash) may be deciphered and stabilized. The document must be handled minimally. The document must be shipped in the container in which it was burned, in polyester film encapsulation, or between layers of cotton in a rigid container.
    Age of a Document
    The earliest date a document could have been prepared may be determined by examining various physical characteristics, including watermarks, indented writing, printing, typewriting, and inks .
    Carbon Paper or Carbon-Film Ribbon
    Used carbon paper or a carbon-film ribbon can be examined to disclose the content of the text.
    Checkwriters
    A checkwriter impression can be compared with a known source. Examining checkwriter impressions may determine the brand or model of the checkwriter.
    Embossings and Seals
    An embossed or seal impression can be compared with a known source. Submit the device to the Laboratory.
    Rubber Stamps
    A rubber-stamp impression can be compared with a known source. Submit the rubber stamp to the Laboratory uncleaned.
    Plastic Bags
    Plastic bags (e.g., sandwich and