N on-requested dictated writings are of value in handwriting comparison because the investigator controls the test and ensures that it is directly comparable to the questioned entries. The investigator also controls the number of known documents prepared, so the document examiner is assured of having a sufficient number of examples of each of he questioned letter combinations and words for comparison. The dictated non-request writings should be in the same format, on the same type of form, and written with a writing instrument similar to that of the questioned document.
T here are two disadvantages associated with dictated writings.
First, the writing is done at one sitting, so the natural variation in the writing may not likely to be as large as in collected writings made individually over a period of time and under varying conditions. Second, the writing may not be entirely natural or representative of the writer's normal habits. Knowing the writings are being collected for the purpose of comparison in a criminal investigation, an innocent person may write more carefully than usual, and a guilty one may intentionally attempt to disguise his handwriting. All of these circumstances will be taken into account during the document examination. N on-request or collected writings avoid the problem of handwriting disguise and generally represent the writer's normal range of variation in writing habits.