NCJ Number
218817
Date Published
July 2000
Length
7 pages
Annotation
This article describes the development, significance, and features of the FBI Laboratory's X-ray database.
Abstract
The scanning electron microscope (SEM) with associated energy dispersive spectrometer (EDS) is commonly used to characterize the structure and elemental composition of a wide variety of materials of forensic significance; however, the usefulness of SEM/EDS has been limited by its inability to archive spectra of various materials within a true database architecture. In order to remedy this deficiency, the FBI Laboratory has designed an X-ray database that consists of storage, query, and display utilities unique to X-ray spectroscopy. The database is designed as a Windows-based application intended to function with a contemporary EDS system on a personal computer (PC). Spectra are converted to the EMSA format that has emerged as an industry standard. Two functional spectral display windows are used, an analysis window and a search window. Imported spectra are processed, analyzed, and stored from the analysis window. The search window displays the spectral matches that result from a search. Display of a single record includes all information stored with that entry, including spectrum, text, composition, and image. Database queries may select individual or multiple criteria, including keyword, material classification, best fit, or composition. The ability to query the spectra of vast numbers of standard materials has improved the ability of the FBI Laboratory to use SEM/EDS in a comprehensive manner. Each of the database utilities has been used in casework to provide spectral manipulation and investigative direction from previously unmanageable associations. The second phase of the project will provide remote access to the database in order to enable data sharing with law enforcement agencies. 5 figures and 2 references