Forensics Journal - Stevenson University 2012

STEVENSON UNIVERSITY (Bandey, 2004, pg.7) PROCESSING METHOD The processing method employed Evident® Conventional Black Fingerprint Powder, a standard black latent print powder. This product method was chosen owing to its ease of application. For each processing, the fingerprint powder was applied to the bottle with a Sirchie® Fiberglass Filament Fingerprint Brush, a standard fingerprint brush. The brush was dipped into the fingerprint powder and then brushed onto the surface of the bottle with a circular, whirling motion until the latent prints darkened. When the latent prints became visible, all excess powder was brushed from the surface. Evident® Clear Fingerprint Tape was then applied to the surface of the bottle. The tape was placed onto the surface of the bottle by covering the darkened prints with the adhesive side of the tape. Pressure was then applied to the tape in order to remove any air bubbles. The tape was then removed from the surface of the bottle and placed onto the surface of a fingerprint lift card, essentially an index card with a section on the back for recording pertinent information. This same method was used for all prints processed. EVALUATION OF PRINTS After all prints were processed using latent print powder, each individual print was evaluated for quality. An evaluation scale was chosen, to provide a proper range of values and a standard. Due to the researcher’s lack of expertise, a scale that evaluated the physical characteristics of the prints, rather than their quality, was needed for comparison purposes. The evaluation did not take into account the prints’ suitability for comparison. The evaluation scale was adapted from a journal article by Helen L. Bandley, entitled “The Powders Process, Study 1: Evaluation of Fingerprint Brushes for Use with Aluminum Powder,” originally published in The Fingerprint Development and Imaging Newsletter, May 2004 edition by the (United Kingdom) Home Police Scientific Development Branch and is shown in Figure 1. Examples of ratings 1-4 are illustrated in Figures 2 through 5. Prints were given a rating of zero when there was absolutely no ridge detail developed or was recoverable. DISCUSSION The inherently random nature of latent prints poses a challenge for the researcher. In order to obtain sufficient and reliable results, it was necessary to consider a number of variables, which in turn had to be controlled so as not to influence or alter the results. The present research was conducted using three mediums for depositing prints. The results of these prints can only be compared to other prints that were deposited in the same manner. Lotion, Evident® Ridge Builder, and sebaceous residue were all used as depositing mediums, and all yielded distinct results. In addition to the variable mediums used, the research also relied on a wide range of donors. The use of multiple donors permitted a more realistic representation of the general population, since no two individuals deposit prints in the same way. This approach required careful controlling and monitoring because each donor secretes different amounts of oil. Therefore, the quality of deposited prints varies from one individual to the next. This is an important issue to consider as comparison between or among individuals might not be possible. FIGURE 1: Evaluation Scale 52

Forensics Journal - Stevenson University 2012 | Page 54