Without a Trace? Advances in Detecting Trace Evidence

• NCJ Number: 200907
• Journal: NIJ Journal Issue: 249 Dated: July 2003 Pages: 2-9
• Date Published: July 2003
• Length: 8 pages
• Publication Series: NIJ Journal
• Agencies: NIJ
• Publication Type: Report (Technical Assistance)

Annotation

This article describes promising new techniques for distinguishing glass evidence, identifying chemical composition, collecting and analyzing explosives, and locating body fluids and fingerprints.

Abstract

Dr. Jose Almirall, associate director of the International Forensic Research Institute, has collaborated with Dr. Douglas Duckworth of Lockheed Martin's Oak Ridge National Laboratory to develop an improved method for analyzing glass elements by using a process called inductively coupled plasma-mass spectrometry (ICP-MS). ICP-MS combines enhanced sensitivity with a multielement capability. This higher level of glass analysis is a valuable tool for distinguishing among all types of glass from very small fragments. In another area of trace evidence, the Idaho National Engineering and Environmental Laboratory has focused on the persistent nature of chemicals. Static secondary ion mass spectrometry (static SIMS) has been used to distinguish trace chemicals and residue on various materials. The goal is to find links between suspected sites and possible offenders. In a third area of trace evidence analysis, Dr. Michael Sigman, a researcher at Oak Ridge National Laboratory, has developed a new method for the rapid analysis of organic explosives at a crime scene. The method uses dry, durable Teflon surface wipes. These wipes offer several advantages over the many different physical and chemical techniques traditionally used to collect and analyze chemical evidence from blast debris. An effective method for locating body fluids and fingerprints at a crime scene has been developed by Colin Smithpeter, a scientist at Sandia National Laboratories in New Mexico. He has developed the Criminalistics Light-Imaging Unit (CLU), which is a camera that uses a multispectral imaging system with various colors of light to view the substance or structure being examined. By using a strobe lamp, signal processing, and improved optics, CLU rejects surrounding light and thereby improves both the sensitivity and specificity of the area being viewed. CLU is five times more sensitive than current fluorescing methods. 13 references