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Follow the evidence submission directions, including Requesting Evidence Examinations and Packaging and Shipping Evidence .
Submit control samples of the unadulterated product.
Package and ship control and suspect samples separately to avoid contamination. Submit samples in leakproof containers such as film canisters or plastic pill bottles. Do not use paper or glass containers.
Use caution to prevent the destruction of latent prints.
    Questioned Document Examinations
    Handwriting and Hand Printing
    The examination and comparison of handwriting characteristics can determine the origin or authenticity of questioned writing, although not all handwriting is identifiable with a specific writer. Intent and such traits as age, sex, and personality cannot be determined from handwriting examinations. Some reasons for inconclusive results include:
Limited questioned and/or known writing.
Lack of sufficiently comparable known writing for comparison.
Lack of contemporaneous writing or lapse of time between execution of questioned and known writing.
Distortion or disguise in the questioned and/or known writing.
Lack of sufficient identifying characteristics.
Submission of photocopied evidence instead of original evidence.
    Procedures for Obtaining Known Writing Exemplars
The text, size of paper, space available for writing, writing instrument, and writing style (handwriting or hand printing) must be as close to the original writing as possible.
Give verbal or typewritten instructions concerning the text to be written. Do not give instructions on spelling, punctuation, or arrangement of writing.
All exemplars must be on separate pieces of paper.
The writer and witness must initial and date each page of writing.
Do not allow the writer to see the previous exemplars or the questioned writing. Remove each exemplar from the writer’s sight as soon as it is completed.
Numerous repetitions may be necessary to obtain naturally prepared writing.
Obtain exemplars from the right and left hands.
Obtain hand-printing exemplars in upper- and lowercase letters.
Obtain a sufficient quantity of exemplars to account for natural variation in the writing.
Obtain undictated writing such as business records, personal correspondence, and cancelled checks or other documents prepared during the normal course of business activity.
    Common Types of Nongenuine Signatures
Traced signatures are prepared by directly using a genuine signature as a template or pattern.
Simulated signatures are prepared by copying or drawing a genuine signature.
Freehand signatures are written in the forger’s normal handwriting with no attempt to copy another’s writing style. Therefore it may be possible to identify the writer(s) who prepared the signature(s).
    Altered or Obliterated Writing
    Documents can be examined for the presence of altered or obliterated writing, and the original writing may be deciphered.
    Typewriting
    Questioned typewriting may be identified with the typewriter that produced it. This is most common when the typewriter is a typebar machine. The identification is based on individual characteristics that develop during the manufacturing process and through use and abuse of the typewriter.
    Typewriters with interchangeable elements (e.g., ball, printwheel, or thimble) are less likely to be associated with questioned typewriting. However, these typing elements may be positively identified with specific texts by examining individual characteristics of the elements.
    Comparison of questioned typewriting with reference standards can determine a possible make and model of the typewriter and/or the typewriter elements.
    Carbon-film typewriter ribbons and correction ribbons retain readable text. These ribbons can be compared with questioned typewritten impressions. Generally, fabric ribbons cannot be read or identified.
    Procedures for Obtaining Known Typewriting Exemplars
If the typewriter has a carbon-film ribbon or correction ribbon, remove it from the typewriter and