NCJ Number
186107
Journal
International Journal of Forensic Document Examiners Volume: 5 Dated: December/January 1999 Pages: 415-423
Date Published
1999
Length
9 pages
Annotation
This paper profiles a case in which a forger broke into the Government United Invoice Lottery System (GUILS) in Taiwan to alter documents; the authors explain a novel method that was used to identify the forged invoices and to prevent the forger from further access to the system.
Abstract
The investigators developed a process to identify a possible method for the extraction of the typographic printing ink. The method first used dichloromethane and 2 percent hydrocholoric acid mixed with methanol solutions to extract the ink. The residual on the invoice was further extracted by using a solution of heated pyridine. Then, the entire sheet was soaked in a hot water bath, washing the extraction without any residual. The results showed that the forgery method was identical and effective. The main reason the forger used the screen printing method instead of the hand-drawing method to do the forgery was the cost-effectiveness of this printing method, simplicity, and easy acquisition. The forgery method was identified due to the examination of printing characteristics of the serial number between the genuine invoice and the forged invoice. The case involved the use of a novel method to identify the variations. The proposed method provided an effective solution to government examiners for preventing the forger from breaking into the particular system. The results also suggest that other similar types of forgery could be reproduced and therefore identified. 5 figures and 4 references