AN X-RAY SPECTRAL DATABASE FOR FORENSIC APPLICATIONS€¦ · AN X-RAY SPECTRAL DATABASE FOR...
Transcript of AN X-RAY SPECTRAL DATABASE FOR FORENSIC APPLICATIONS€¦ · AN X-RAY SPECTRAL DATABASE FOR...
AN X-RAY SPECTRAL DATABASE FOR
FORENSIC APPLICATIONS
Dennis WardFederal Bureau of Investigation
Quantico, DC 22135
Characterize
Compare
Identify
What are the structural and chemical characteristics?
Could items have come from the same source?
What is it?
Existing Deficiencies in SEM/XRF Utilities
• “Quant based”• Cannot search for best fit• Cannot compare specific compositions • Cannot search for text information• Cannot display nested spectra• Cannot associate an image with
spectrum
Spectrum Analysis WindowSpectrum Analysis Window
Select Search CriteriaSelect Search Criteria
Best Fit SearchBest Fit Search
Compare Case SpectraCompare Case Spectra
• Demonstrate GSR particle populations• Demonstrate “other” populations • “Unusual” particle composition query• Bullet lead/jacket composition “screen”
Summary of uses(GSR/Firearms)
Individual recordIndividual record
“Projects”“Projects”(Speer Lawman 9mm Luger)
“Best fit” query“Best fit” queryExample: Winchester Super Clean NT primer cup
Query for specific compositionQuery for specific compositionExample: Example: SbSb >5%>5% SbSb, , BaBa >5% >5%
view GSR populationview GSR populationExample: Winchester 25 auto
“environmental” particle composition“environmental” particle compositionExample: Brake particles
Confirm questioned particle to GSRConfirm questioned particle to GSR
SWGFAX(Scientific Working Group for the Forensic
Archive of X-ray spectra)
• Belgium, US, Germany, Canada, and California
• Confirmed utility of database• Consensus for design
♦ MATERIAL IDENTIFICATION ♦ PRODUCT IDENTIFICATION♦ MANUFACTURER IDENTIFICATION♦ CRITICAL SUDIES OF COMPOSITION
♦ FBI LABORATORY♦ FEDERAL LABORATORIES♦ INDUSTRY♦ STATE AND LOCAL CRIME LABORATORIES
NATIONAL XNATIONAL X--RAY DATABASERAY DATABASE(PROPOSED FOR DEVELOPMENT)
Spectral Library and Classification Explorer, developed by the FBI and xk, Inc. as a “stand alone” application for spectra management
Scanning Electron Microscope
X-ray Fluorescence - laboratory use
X-ray Fluorescence - field use
(proposed for development)
SS 316
SEM/EDS
SS330.str
Fe
Cr
Ni
Cr, (Mn) Fe
Ni????
SS 330
0.00 2.00 4.00 6.00 8.00 10.00 12.00 14.00 16.00 18.00 20.00
SS 316 XRF
SS 316 Micro
First response capability
• Elemental analysis• Wide elemental range (Mg +)• Qualitative• Portable (suitcase size)• Interface to database (SLICE)• = XRF
www.fbi.gov
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