ASTM E2494-08

The procedures outlined here are grounded in the generally accepted body of knowledge and experience in the field of forensic document examination. By following these procedures, a forensic document examiner can reliably reach an opinion concerning the source of the item(s) examined.

The examinations described in this guide pertain to those documents prepared on typewriters and can consist of a wide range of forensic examinations. Some or all of these procedures can also be applicable to examinations of documents prepared on other impact and nonimpact printing devices.

Examinations can be conducted to classify a typestyle and to determine the possible make and model of typewriter(s) by comparison with a typestyle library.

Examinations and comparisons of typewritten documents can be conducted for the purpose of determining whether or not they are from a common source.

Examinations and comparisons of typewritten documents can be conducted for the purpose of determining whether or not they were produced using a particular typewriter or type element.

Examinations and comparisons of a typewritten document(s) with a typewriter (or particular part(s) of a typewriter) or type element can be conducted for the purpose of determining whether or not a document was prepared with that equipment.

Examinations and comparisons of a typewritten document(s) with typewritten documents of known date can be conducted for the purpose of determining whether or not a document was prepared on or about the date indicated.

Examinations of typewritten documents can be conducted for the purpose of determining whether or not a document was typed in a single, continuous operation.

Examinations of typewriter ribbons or correction media (see lift-off and cover-up), or both, can be conducted to determine the content or source of the material typed on them or corrected with them, respectively.

1.1 This guide covers procedures that should be used by forensic document examiners (Guide E 444) for examinations and comparisons involving typewritten items and related procedures.

1.2 These procedures are applicable whether the examination and comparison is of questioned and known items or of exclusively questioned items.

1.3 These procedures include evaluation of the sufficiency of the material (questioned, or known, or both) available for examination.

1.4 Procedures are also given for taking exemplars from typewriters and the proper handling of typewriters or parts of typewriters that might be relevant.

1.5 These methods can also be applicable (in whole or in part) to examinations of documents prepared on other impact and nonimpact printing devices.

1.6 The particular methods employed in a given case will depend upon the nature of the material available for examination.

1.7 This guide might not cover all aspects of unusual or uncommon examinations of typewritten items.

1.8 This guide cannot replace training (Guide E 2388) or experience and should be used in conjunction with professional judgment.

1.9 The values stated in inch-pound units are to be regarded as standard. The values given in parentheses are mathematical conversions to SI units that are provided for information only and are not considered standard.

1.10 This standard does not purport to address all of the safety concerns, if any, associated with its use. It is the responsibility of the user of this standard to establish appropriate safety and health practices and determine the applicability of regulatory limitations prior to use.