The value of document examination is that a definite conclusion can often be reached. A competent examiner has the ability to state that particular person or instrument produced the document in question, provided certain conditions for evidence collection and standard collection are met. This type of testimony has been accepted by the courts in this country for many years. While handwriting and typewriting comparisons are the most common types of examinations performed by the document examiner, his expertise spans a wide variety of related examinations. Comparisons of paper are possible, but a positive identification is seldom obtained.
New typewriters are also difficult to identify.
The document examiner is also trained in the use of special photographic techniques when needed. Information that cannot be determined with certainty by handwriting examination are the age and sex of the writer. As in other areas, the proper collection and preservation of the evidence and the submission of adequate and suitable standards are of the utmost importance in obtaining the best results possible from the laboratory. The questioned document must be adequately identified with initials, dates, and other pertinent data. This can be accomplished by either writing on the back of the document itself, or, if legal aspects or good judgment indicate otherwise, by placing it in a clear plastic envelope with a slip of paper inside showing the pertinent data.