NCJ Number
76413
Journal
International Criminal Police Review Issue: 342 Dated: (November 1980) Pages: 238-250
Date Published
1980
Length
13 pages
Annotation
The technique of establishing the chronological sequence of two crossing lines appearing in a document, a procedure often necessary for establishing fraud, is reviewed as developed at Lausanne University's Institute of Forensic Science and Criminology (Switzerland).
Abstract
The technique involves several steps: (1) an attempt to classify types of line intersections based on the type and nature of the lines themselves, (2) a study of the various types of line intersections, (3) the use of examination techniques that do not affect the document, and (4) the use of examination techniques which do affect the document. As much information as possible has been acquired about the structure and nature of lines produced by a movement of the writing instrument on the paper, as well as the structure and nature of lines produced without any movement of the instrument. The study of the dynamic aspects of the various kinds of intersection includes consideration of 'homogeneous intersections,' where the two lines are produced by the same instrument or by two identical instruments, and 'heterogeneous intersections,' where intersections are made with differing instruments. The following techniques for examining line intersections without damaging the document are described: (1) examination under the stereomicroscope, with the optical axis perpendicular to the paper's surface; (2) use of a cross-screen filter; (3) use of a special camera; (4) examinations under a stereomicroscope with its optical axis at an angle to the paper's surface or with curvature of the paper; (5) techniques using long or short ultraviolent or infrared incident lighting; and (6) 'pseudo low relief.' Photographic illustrations are provided.