NCJ Number
211809
Journal
Forensic Magazine Volume: 21 Issue: 5 Dated: October/November 2005 Pages: 15-17
Date Published
October 2005
Length
3 pages
Annotation
This article assesses the features of laser-induced breakdown spectroscopy (LIBS) that make it suitable for analyzing various types of forensic evidence; and its use in the chemical analysis of wood in a murder case in Collin County, TX, is described.
Abstract
The greatest advantage of LIBS is its ability to perform remote chemical analysis of samples with minimal handling and little or no sample preparation. Further, the instrumentation and operation of a LIBS system is simpler than some of the more sensitive techniques, and its rapid analysis time (a few minutes) make it amenable for real-time analysis of chemical processes. In the murder case featured in this article, the killer attempted to dispose of the victim's body by burning it on a pyre of firewood. In the course of the investigation, detectives learned that the suspect had brought logs to a party at about the same time the victim was known to be missing. Investigators collected 10 logs from the murder-scene fire and 4 logs from the party fireplace in order to compare them. If the logs could be determined to come from the same group, it might help to place the suspect at the crime scene. If the chemical composition of logs from the two locations matched, it could be assumed they came from a common source, perhaps even from the same tree. The LIBS technique assessed the presence and amounts of specific elements in the wood sample. Little difference was found in the chemical spectra between charred logs and unburned logs; the low temperatures that charred the murder-scene logs were not sufficient to volatilize and remove the elements.