The Indignant Indigent has added two news link to the "Resources" toolbar at the right entitled "Challenging Firearms Examiners" (two parts). The links lead to two articles by Professor Adina Schwartz of the John Jay College of Criminal Justice that appeared last year in the New York State Defender's Association publication, The Champion. In the articles, Professor Schwartz points out the weaknesses inherent to any firearms examiner's testimony and provides scientific evidence to support the position that no firearms examiner can reliably testify that he has found the one-and-only weapon that discharged a particular bullet or shell casing. The articles should be required reading for any attorney before cross-examining a firearms expert. You can also find the articles here and here.
It should also be known that three recent federal cases highlight the problems inherent in firearms identification and suggest that such testimony is vulnerable to legal challenges despite its having been long accepted in evidence, often without much debate (see US v. Glynn, 578 F Supp 2d 567 [SDNY 2008]; US v Montiero, 407 F Supp 2d 351, 355 [Dist Mass 2006]; and US v Green, 405 F Supp 2d 104).