NCJ Number
225766
Journal
Journal of Forensic Identification Volume: 59 Issue: 1 Dated: January/February 2009 Pages: 7-25
Date Published
January 2009
Length
19 pages
Annotation
Various types of tape were used in testing the use of liquid nitrogen as a means of separating tapes that have been stuck together prior to testing for latent fingerprints.
Abstract
Using liquid nitrogen made the separation of the tapes that were stuck together adhesive side to nonadhesive side much less cumbersome. Specifically, the duct tape was not subjected to the usual stretching and pulling that is associated with the normal separation of duct tape that is stuck together with the adhesive side against the nonadhesive side. Liquid nitrogen had no noticeable effect on the latent fingerprints present on the adhesive side of the tape. When adhesive sides of tapes were adhered to adhesive sides, reverse or mirror images of latent prints occasionally appeared on each side of the separated tape. When processed, the latent print was cut in half, depositing a portion of its matrix to each side. The successful development of latent prints was achieved even in the longest time test of 36 days for the adhesive-to-adhesive group on tapes that had been protected by moderate indoor temperatures. On the other hand, there was a poor likelihood of finding latent prints on tapes in outdoor environments for more than a few days when they were stuck adhesive side to adhesive side. Of the 20 types of tapes tested--including box tape, packing heavy duty tape (clear and tan), and various brands of duct tape--the duct tapes were the most amenable to separation with liquid nitrogen. In order to test whether the latent prints would be adversely affected by liquid nitrogen, some tapes were processed with Sticky-side Powder after they had been submerged in the liquid nitrogen. Testing methods are described in detail. 9 figures, 6 tables, and 3 references