Analytical and Transfer Characteristics of a Fluorescent Detection Spray: Implications for Subvisible and Nanotrace Particle Transfers

• NCJ Number: 253462
• Date Published: 2018
• Length: 10 pages
• Author(s): Christopher S. Palenik; Kelly Brinsko-Beckert; Joseph Insana; Skip J. Palinik
• Agencies: NIJ-Sponsored
• Publication Type: Research (Applied/Empirical), Report (Study/Research), Report (Grant Sponsored), Program/Project Description
• Grant Number(s): 2015-DN-BX-K033
• Award: Nanotrace: Applications of subvisible to nanoscale particles in trace evidence

Annotation

This article provides a microanalytical characterization of a common fluorescent tracer and the approaches by which this powder (or analogous powders) may be applied, detected, and specifically identified in quantities that range from major to trace.

Abstract

Fluorescent detection sprays are applied to objects to elucidate evidence of contact. Billed as an invisible powder, evidence of contact between objects may be visualized through illumination by ultra-violet light, which causes the fluorescent tracer to luminesce. While the presence of the fluorescent powder on a suspect or object is often used as evidence of direct contact, the fine nature of the powder, which is comprised of sub-visible particles that are generally less than 10 microcetres in diameter, lends itself to higher-order transfers that do not necessarily involve the original object. Due to the small particle size and light-yellow color, the particles are generally invisible to the unaided eye in white light. This increases the opportunity for unwanted or unanticipated transfers (i.e., contamination). The current research illustrates the ease of higher order cross-transfers (up to the 10th order) and the considerations necessary to maximize the evidentiary value of sub-visible particles and nanotraces, while minimizing the chances of cross-contamination. (publisher abstract modified)