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Developing and Fixing Latent Fingerprints: A Simple Method

NCJ Number
138652
Journal
Canadian Society of Forensic Science Journal Volume: 25 Issue: 2 Dated: (June 1992) Pages: 119-121
Author(s)
A K Single; O P Jasuja
Date Published
1992
Length
3 pages
Annotation
This article describes a simple method for the development of latent fingerprints with dry photostat toners and their fixing with the vapors of ethyl ether.
Abstract
To test the practical applicability of this method, latent fingerprints were made on various types of objects such as paper, wood, tin, leather, rexine, glass, and a plastic sheet. The prints were developed with drug photostat toner in the same way in which fingerprints are developed with the conventional fingerprint powders. The photostat toners have very fine grain size and strong affinity towards the deposits left by the contact of friction skin with the objects. After removing the excess of toner, the developed fingerprints were fixed/fused with the surface by carefully spraying ethyl ether with a fine nozzle atomizer from a distance of approximately 10 cm. The fingerprints are fused with the substratum in a few minutes without any apparent change in their details after development. Immediately after spraying the solvent, the area bearing fingerprints may be covered with a glass hood or an inverted funnel to avoid unwanted inhalation of the vapors of ethyl ether and to enhance the process of fixing. Once the fingerprints are fixed, they become permanent, and they do not get smeared off or damaged with accidental rubbing or disturbance of the surface bearing them. After preserving the fingerprints for approximately 6 months, there was no apparent change in the quality of the ridges or their permanence. This method was found by the authors to be convenient and simple, and it eliminates the need to lift fingerprints on cellotapes to prevent them from subsequent damage. 2 figures and 2 references