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Forensic Light Source Enhancement of Authentiprint Identification System Fingerprints

NCJ Number
Journal of Forensic Identification Volume: 51 Issue: 4 Dated: July/August 2001 Pages: 361-366
John W. Ohlson; William McQuay
Date Published
6 pages
This article describes how the Omnichrome 1000 Forensic Light Source luminesced fingerprints on "bad" checks coming through Central Florida's Authentiprint Identification System (AIS).
Supermarkets and other high-volume check cashing facilities in Central Florida use the AIS. The system consists of a dispenser of chemically treated stickers. On top of the dispenser is a pad that is impregnated with another chemical. When a check is cashed, a sticker is affixed to the check. A finger (usually the right index or thumb) is pressed on the pad and then onto the sticker. The reaction of the chemicals results in a visible fingerprint. In a recent series of "bad" checks, a problem arises when an insufficient amount of the chemical was transferred to the finger from the pad so as to allow a chemical reaction on the sticker. This may have been due to drying of the pad or insufficient pressure on the pad or sticker. In addition, investigations had discovered that some subjects, prior to cashing a check, allowed a foreign substance, e.g., Elmer's glue or clear fingernail polish, to dry on the finger. This prevented a transfer of the chemical in the shape of fingerprint ridges. The Omnichome 1000 Forensic Light Source was selected to determine whether the prints would luminesce. The individual prints were observed on all five settings of the Omnichrome 1000. The best setting proved to be 570 nanometers, using red goggles. The enhanced fingerprints that were originally unidentifiable were identified. The fingerprints were photographed using Ilford FP4 Plus, 125 ISA, black and white film, and the Omnichrome 1000 light source set at 570 nanometers. A Tiffen #25 red filter was also used to duplicate the results seen with the red goggles. The enhanced prints were entered into AFIS for searching. 4 figures