Basic Information about Document Examination
No two people write exactly the same way. Nor, for that matter, does one single person as your own signature varies over time. Determining who wrote a given writing or printing sample is accomplished by identifying a combination of handwriting traits that are unique to one person only.
Requirements for Document Examination
Because nobody writes exactly the same way twice, I need to determine how much a person varies his or her handwriting. Doing this requires a sufficient amount of authentic or "known" writing to compare against the questioned handwriting. The following is a guide to what I need in order to conduct a handwriting comparison:
- I prefer to examine original documents. Photocopies do not reproduce the finer features of handwriting such as pressure, ductus, and line crossing.
- Examination of originals also eliminates the possibility of a forgery by cutting, pasting and copying a signature onto a document. The absence or loss of an original can itself be suspicious-especially if the destruction or loss of a document is out of character for the situation. Even so, originals are not always available. In such cases, it is common for document examiners to give a qualified opinion when examining non-originals.
- I need a sufficient amount of known writing, called exemplars, which are used to compare against the questioned writing. Many cases involve questioned signatures. In such cases, five to twenty-five signatures is sufficient; and...
- A person's handwriting or handprinting habits can change over time. Consequently, the exemplars and questioned writing should be contemporary with each other. Ideally, both bodies of writing should be written with a year or two of each other.
Sometimes the quantity and quality of writing samples available for examination does not exactly meet the criteria listed above. I can still perform the forensic document examination, but may give a qualified opinion.
My collegue Richard Orsini has put together a wonderful list of typical places where you can locate handwriting samples.
Request Writing Samples
When there is a very limited amount of exemplars available, it may become necessary to have a person provide writing samples. Writing samples executed for the purpose of handwriting comparison are known as "request writing". Here is some useful information about taking request writing samples by Katherine Koppenhaver of the Baltimore, MD area.
Another collegue, Emily Will, has compiled a list of famous document examination cases, available here.