U.S. flag

An official website of the United States government, Department of Justice.

NCJRS Virtual Library

The Virtual Library houses over 235,000 criminal justice resources, including all known OJP works.
Click here to search the NCJRS Virtual Library

Application of Oil Red O Following DFO and Ninhydrin Sequential Treatment: Enhancing Latent Fingerprints on Dry, Porous Surfaces

NCJ Number
243812
Journal
Journal of Forensic Identification Volume: 63 Issue: 4 Dated: July - August 2013 Pages: 387-423
Author(s)
Lawrence McMullen; Alexandre Beaudoin
Date Published
August 2013
Length
37 pages
Annotation
In this study, an assessment of the usefulness of ORO with the DFO (1,8 Diazafluoren-9-one) and ninhydrin (NIN) used consecutively in a sequence in recovering latent fingerprints from dry, porous surfaces was conducted.
Abstract
This research demonstrated that (1) the pretreatment of evidence with DFO and NIN did influence the ORO result, but did not prevent development of useful fingerprints with the sequential process, (2) the ORO sequential treatment did present lower contrast than ORO alone, but this lower contrast did not limit the ability of the fingerprint examiner to use the prints, and finally, (3) the addition of ORO following the DFO and NIN used consecutively enhanced fingerprints already developed with those tow amino acid reagents and even developed previously undetected fingerprints. This research supports using ORO in laboratories to visualize or even locate previously undetected prints on dry, porous surfaces. The recovery of fingerprints from porous surfaces is often problematic, because fingerprints cannot usually be directly lifted from such objects. As well, the fingerprints are often not visible to the naked eye. DFO and NIN are amino acid-specific chemicals and are widely used to visualize latent prints on such surfaces. When these two fingerprint reagents are used consecutively, more fingerprints are able to be identified. Because Oil Red O (ORO) targets lipids, the strategy is to add this reagent in the sequence of DFO and NIN used consecutively to enhance previously undetected latent prints on dry, porous surfaces (e.g., paper). Targeting lipids can be a valuable asset to enhance prints that contain fewer amino acids or prints that have been exposed to a humid environment. (Published Abstract)