U.S. flag

An official website of the United States government, Department of Justice.

Forensic Elemental Analysis of Materials by Laser Induced Breakdown Spectroscopy (LIBS)

NCJ Number
Proceedings of the SPIE - The International Society for Optical Engineering Volume: 5778 Dated: 2005 Pages: 657-666
Date Published
10 pages
Since a newly developed Laser Induced Breakdown Spectroscopy (LIBS) instrument (Foster and Freeman Ltd., Evesham, U.K.) has been evaluated as a tool for the forensic elemental analysis of glass and compared in performance to other elemental methods in order to determine the utility of comparing casework sized glass samples, the current article reports on developments in the instrumental design of this LIBS system, which is specifically designed to address the analytical requirements of the forensic laboratory.

Materials analysis and characterization can provide important information as evidence in legal proceedings. Although the utility of trace elemental analyses for comparisons of glass, paint chips, bullet lead, and metal fragments has been shown to provide a high degree of discrimination between different sources of these materials, the instrumentation required for the generation of good analytical data in forensic comparisons can be beyond the reach of many forensic laboratories. Scanning Electron Microscopy with an Energy Dispersive Spectrometer (SEM-EDS), X-Ray Fluorescence (XRF), Laser Ablation Inductively Coupled Plasma Atomic Emission Spectroscopy (LA-ICP-AES) and, more recently, LA-Inductively Coupled Plasma Mass Spectrometry (LA-ICP-MS) have been used in forensic laboratories for elemental analysis determinations. The current article includes a discussion of the utility of the LIBS system for the analysis of glass, paint, metals, gun shot residue, and other matrices. The power of the LIBS-based elemental analysis to discriminate between different glass samples is also compared to the discrimination power of SEM-EDS, XRF and LA-ICP-MS. The relatively low cost (expected to be ~ $ 60,000.), ease of operation, and almost non-destructive nature of the LIBS analysis makes the technique a viable forensic elemental analysis tool. (publisher abstract modified)

Date Published: January 1, 2005