NCJ Number
130214
Journal
Journal of Forensic Sciences Volume: 36 Issue: 3 Dated: (May 1991) Pages: 820-837
Date Published
1991
Length
18 pages
Annotation
The diffuse reflectance infrared Fourier transform spectroscopy (DRIFTS) technique is applied to an analysis of 152 black and color toners used in photocopiers and laser printers available on the Swiss market.
Abstract
Of this group 149 of these toner samples taken from the photocopied documents and raw toner powders were classified into 36 distinct groups on the basis of their infrared (IR) spectra. A sample of toner from the surface of a questioned document which was produced on a photocopier or laser printer was removed and its IR spectrum was determined with the diffuse reflectance technique. The class of toner was then ascertained by comparison with a collection of standard spectra. Information of the compatibility of each type of toner can be used to produce a list of photocopiers or laser printers that could have produced the questioned document. The technique is not affected by variations between batches of toners, age of the photocopy, and fingerprint development reagents such as ninhydrin. This analysis of 152 different toners has provided an infrared database representing major photocopying toners on the Swiss market. This database together with information on the compatibility of each toner provides a forensic examiner with useful information in the analysis of questioned document cases. 3 tables, 15 figures, and 7 references (Author abstract modified)