NCJ Number
198076
Journal
Journal of Forensic Sciences Volume: 47 Issue: 6 Dated: November 2002 Pages: 1274-1277
Editor(s)
Michael A. Peat Ph.D.
Date Published
November 2002
Length
4 pages
Annotation
This paper briefly presents experiments of ninhydrin sublimation in vacuum to detect latent fingerprints on thermal paper.
Abstract
Ninhydrin is the oldest and best-known detection reagent for latent fingerprints on porous surfaces reacting with amino acids of fingerprint sweat. With several alternative methods for the detection of latent fingerprints on thermal paper having been identified, the ninhydrin sublimation under reduced pressure was seen as a better method in the detection of fingerprints on thermal paper. In this method, latent fingerprints become visible in rich detail without the background black staining from the application of ninhydrin solutions on thermal paper. After a successful initial experiment, the sublimation conditions for fingerprint detection were optimized and additional experiments were conducted on ninhydrin sublimation. The experiments were carried out in a 50 by 50 by 50 cm vacuum chamber. The experiments showed that ninhydrin sublimation is very useful for porous samples working well on normal white paper, thermal paper, and euro notes. Ninhydrin sublimation takes not much more time than the commonly used dipping process. Future investigations are recommended and planned to improve contrast, based on densitometric measurement, for objective comparison of gradual differences.