Book Review: Committee on Scientific Assessment of Bullet Lead Elemental Composition Comparison. (2004). Forensic Analysis: Weighing Bullet Lead Evidence. Washington, DC: National Academies Press, pp. 226

• Date: 01 December 2007
• DOI: 10.1177/0734016807310633
• Published date: 01 December 2007
• Author: Julian Tyson
• Subject Matter: Articles

Science Service are discussed, as well as issues in forensic science education, although

there are no comments on the U.K. or European perspective, which is disappointing as there

have been a number of reports published recently such as Science and Technology

Parliamentary Select Committee’s Forensic Science on Trial (2005). However, the inclusion

of these wider issues does very much to add value to the book and place forensic science

in the context of a changing external environment. In summary, this text provides readers

with a thorough introduction to forensic science principles and practice that will greatly

assist their understanding and appreciation of the discipline area.

Julie Mennell

Northumbria University, Newcastle Upon Tyne, UK

Committee on Scientific Assessment of Bullet Lead Elemental

Composition Comparison. (2004). Forensic Analysis: Weighing Bullet

Lead Evidence. Washington, DC: National Academies Press, pp. 226

DOI: 10.1177/0734016807310633

Sometime in 2002, the FBI asked the National Research Council (NRC) to conduct an

impartial assessment of the soundness of the principles underlying the compositional analysis

of bullet lead (CABL), paying particular attention to three topics: the analytical method, the

statistical basis of comparisons, and interpretation of the results. The committee, which met

on four occasions in 2003, released its report on February 10, 2004, and on September 1, 2005,

the FBI pronounced that CABL was dead.

Not all bullets have the same chemical composition, so if a bullet fragment found at a

crime scene (the CS bullet) and a bullet found in the possession of a potential suspect (the

PS bullet) are analyzed to determine the concentrations of seven elements thought to form the

basis of a discrimination procedure (antimony [Sb], arsenic [As], bismuth [Bi], cadmium

[Cd], copper [Cu], silver [Ag] and tin [Sn]), what can be concluded from the results of this

CABL? The prosecution is trying to establish a connection between the CS and PS bullets

and would like to produce evidence that they come from the same box. On the other hand,

the defense wishes to present evidence that the CS bullet did not come from the box(es) in

the suspect’s possession.

If it were possible to measure the concentrations of the relevant elements to a very large

number of significant digits, then all bullets would be different (they would have a unique ele-

mental “fingerprint” or “profile”). This scenario does not help anyone. On the other hand, if

the method gave rather fuzzy results with large ±terms, then all bullets would be identical.

This scenario does not help anyone either. But as it happens, the performance of the method

that is actually used is somewhere in between, and so because of the variations in the manu-

facturing processes, bullets are (a) distinguishable from some and (b) indistinguishable from

others. The book devotes quite a lot of space to convincing the readers of this. To help make

the case, the committee creates the concept of a compositionally indistinguishable volume of

lead (CIVL), which yields, at the end of the manufacturing process, a number of bullets that

are analytically indistinguishable. The analytical method, which involves chemical reactions

(to dissolve the target elements, but not the lead) followed by measurement of the solution

478 Criminal Justice Review