20.1: Questioned Document

• Questioned documents need not be a piece of paper; it can be any object.

• To be a document, it must contain linguistic or numerical markings that are put there by handwriting, typewriting, copying, computer printing, or by other means.

20.2: Handwriting Comparisons

Handwriting changes over time. Handwriting can also change with changes in physical and emotional condition. It also varies by the type of writing instrument and medium (e.g., paper) used.

The ability of a questioned document examiner to identify the author of a handwritten document by comparison of unknowns with exemplars depends upon two factors:

1. There must be sufficient individual characteristics present in the unknown sample and

2. There must be sufficient samples of the purported writer’s authentic handwriting.

If both of these conditions are met, then questioned document examiners believe that it is possible to individualize an unknown handwriting exhibit to a particular person. If either of the above conditions is not met, then an equivocal conclusion may be necessary; that the suspect’s writing could be the source for the unknown writing.

Handwriting Comparison Characteristics

• Spacing between letters

• Spacing between words

• Relative proportions between letters and within letters

• Individual letter information

• Formation of letter combinations

• The overall slant of the writing

• Connecting strokes

• Pen lifts

• Beginning and ending strokes

• Unusual flourishes

• Pen pressure

Collection of Handwriting Exemplars

1. Exemplars

   • Two types of exemplars:

     • Requested writings – samples taken from someone for the purpose of comparison with a questioned document.

     • Non-Requested writings –  subject’s writing that are taken in the normal course of business or personal transactions. They might include checks, bills, a diary, deeds, etc.

• Proper Collection of Requested Writings

  • The most important consideration is that there must be a sufficient amount of writing to ensure that the normal variations that are present in everyone’s handwriting are represented.

  • Each writing sample should be on a separate sheet of paper and should be removed from the sight of the writer before collecting the next sample.

  • Requested writings should be collected by dictation, not copying.

  • Dictated passages should be long. This will also help uncover attempts to deliberately alter handwriting because the longer someone is forced to write, the harder it is to make deliberate alterations to what is essentially a subconscious process.

  • The requested writing should contain some words and phrases that are present in the questioned document.

  • To the extent possible, the subject should be supplied with the same type of writing instrument and paper used in the questioned document.

2. Signatures

   1. A single signature may be the sole handwriting on the entire questioned document, giving rise to problems that the sample may be insufficient for a definite conclusion.

      • Formal signatures – used on official documents such as wills or deeds.

      • Informal signatures – used in routine correspondence such as personal letters, etc.

      • Stylistic signatures – would be used in signing checks, credit card receipts, etc.

      • Forged signatures – traced signatures; some forgers practice copying the authentic signatures.

20.3: Printed Documents

1. Typewriters:

   1. The font type and size are generally characteristic of particular manufacturers’ models of typewriters, so a questioned, typewritten document can be compared with library entries to determine the make and model used.

2. Laser Printers and Copiers:

   1. There are situations where extraneous marks or blotches of toner may show up repeatedly in the same location until the machine is cleaned or repaired. If the questioned document and exemplars both show these same markings in the same location on the copy, this may provide individual information about the source of the questioned document.

   2. If there are no reproducible, extraneous markings on the paper, and the source of the copy is not known, it may still be possible to determine the make of the copier or printer by chemical analysis and comparison of the toners with known samples.

3. Inkjet Printers:

   1. As with laser printers and copiers, it is not normally possible to trace a document written on an inkjet printer back to a specific machine.

4. Fax Machine:

   1. Facsimiles possess a header called a transmitting terminal identifier (TTI).

   2. The TTI can be a very important characteristic in the comparison of known and unknown facsimiles.

   3. It will usually be in a special font that is different from the text font, and attempts to forge TTIs and place them on a document are usually detectable by document examiners.

20.4: Other Examinations

Document Alterations

• Obliteration – overwriting of a sample of writing or printing with another writing instrument.

• Erasures

  • Abrasive Erasures – involves removing writing with an abrasive eraser material.

  • Chemical Erasures –  involve dissolving or bleaching ink so that it is no longer visible.

• Indented Writings

  • Electrostatic Detection Apparatus (ESDA) – uses a toner that is deposited preferentially in the indented writings so that they can be visualized.

• Charred Documents – very fragile documents because they have almost been destroyed.

Ink Samples

• Understanding the composition of an ink sample and the chemical changes that it undergoes as it dries can be very important in several types of document cases.

• The inks for each of the pen and printer types are formulated especially for the ink delivery system. Inks can be quite complex materials.

• When the composition of an ink sample is determined, it can help determine what type of writing instrument it came from.

• Sampling – accomplished by using a blunt-point syringe needle that takes tiny plugs from individual letters in the writing. Many plugs may be taken from a writing sample as long as there are sufficient writings available to maintain legibility.

• Thin-Layer Chromatography – the most popular and one of the easiest methods of ink analysis and comparison.

• Infrared Spectrophotometry – shows absorption peaks for all the components of the ink at one time, including the solvent, dyes, and additives.

• Laser Desorption Mass Spectrometry – can be used to track an ink dye as it ages.

Artificial Aging of Inks

• Heating at 100°C for a few minutes or hours can age a document by several months.

• Since heating may cause unwanted interactions between ink and paper, other methods of artificial aging are also being studied.

  • The use of UV light and using an oxygen-rich atmosphere.

• Whatever process is used, it must age the ink in the same way that natural aging takes place; that is, the same chemical processes must take place so that the artificial and natural aging processes can be correlated.