EXHIBIT A Bullet Lead

Recent applications of bullet profiling have been controversial. Forensic chemists have employed elemental data to link bullets to boxes of cimmunition and to original batches of smelted lead. The controversy swirls around an issue we have seen and will see again in this text The characterization of inter- and intrasample variation in mass-produced items. Bullets are such items in the article cited at the end of this exhibit, it was noted that about 100,000 pounds of lead are used to make millions of bullets. The lead contains many minor and trace constituents that could conceivably be used to characterize each batch of bullets. However, to date few data are available concerning what are normal expected variations in these trace and minor 

Source Smith, W. D. Controversy Over Forensic ICPMS Method. Analytical Chemistry— A Pages (2002), 411A. 

Strontium Zinc and titanium Sr, Al, Cu, spherical particulates with Sr and trace Ba Zn, Ti Pb-Sb-Ba Pb-Ba, Pb-Sb, Pb, Sr, Sr-Pb-Sb-Ba Particulate with T1O2 core with various elements as coating Ti Zn 

Source Summarized and adapted from Romolo, F. S.. and P. A. Margot, Identification of Gunshot Residue A Critical Review, Forensic Science International 119 (2001), 195-211. 

Methods of analysis for GSR have evolved along with the instrumentation available for elemental analysis. Prior to the advent of scanning electron microscopy-energy-dispersive X-ray (SEM-EDX) techniques, (flame and graphite furnace) atomic absorption was the principal analytical technique employed. Suspected GSR was collected with the use of wipes or swabs moistened with 1% nitric acid, and the residue collected was introduced into the instrument. Less frequently used were neutron activation analysis (NAA), anodic stripping voltammetry, and photoluminescence techniques. ICP methods (AES and MS) appear promising, but have not been widely used to date for GSR. 

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