Identification of Photocopiers from Fusing Roller Defects

• NCJ Number: 134451
• Journal: Journal of Forensic Sciences Volume: 37 Issue: 1 Dated: (January 1992) Pages: 130-139
• Author(s): F J Gerhart
• Date Published: 1992
• Length: 10 pages
• Publication Format: Article
• Publication Type: Report (Technical)
• Language: English
• Country: United States of America
• Note: Presented at the 48th Annual Conference of the American Society of Questioned Document Examiners, 1990, San Jose, California

Annotation

This study examined a sample of 27 photocopiers using the indirect electrostatic process for fusing roller damage of significance to the forensic document examiner.

Abstract

Included in the sample was one machine that had been submitted to the laboratory in a case involving the questioned origin of photocopied documents. The remaining photocopiers were in use in a typical government office environment. Distinctive indentation patterns were present on some copies produced which were sufficient for identification and for establishing that copies had been in physical contact with the copiers. Of the 27 photocopiers examined, 22 percent displayed identifiable indentations on copies produced from worn and damaged fusing rollers. With all machine marks appearing on the copies included, a positive association could be made 37 percent of the time. In view of the high degree of potential for association, as well as the opportunity to establish that a questioned copy was in physical contact with a particular copier, the author recommends that fusing rollers be considered a key component in the identification of photocopy machines. He also notes that the current results reflect the frequency of damage to Teflon-coated heat and pressure rollers only. Since laser printers use the same toner fixing process as photocopiers, worn fusing rollers may produce distinctive marks on laser copies as well. 16 references, 1 table, and 3 figures (Author abstract modified)