Chapter 20: Questioned Documents

Electrostatic Detection Apparatus

Electrostatic Detection Apparatus

Uses a toner that is deposited preferentially in the indented writings so that they can be visualized.

Laser Desorption Mass Spectrometry

Can be used to track an ink dye as it ages.

Obliteration

Overwriting of a sample of writing or printing with another writing instrument.

Thin-Layer Chromatography

Most popular and one of the easiest methods of ink analysis and comparison.

Informal signatures

________- used in routine correspondence such as personal letters etc.

Chemical Erasures

Involve dissolving or bleaching ink so that it is no longer visible.

Requested writings

Samples taken from someone for the purpose of comparison with a questioned document

Signatures

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 will 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

Obliteration

Overwriting of a sample of writing or printing with another writing instrument

Abrasive Erasures

Involves removing writing with an abrasive eraser material

Charred Documents

Very fragile documents because they have almost been destroyed

Sampling

Accomplished by using a blunt-point syringe needle that takes tiny plugs from individual letters in the writing

Thin-Layer Chromatography

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